Updated July 18, 2017
The Diesel Page operates as a subscriber based web magazine. This means all new feature articles are normally available on-line for a period of time. New and original articles, product reviews and/or tech pages are added throughout each year. The Book Reprint Section contains a preview for all of the available books, which contain the articles and product reviews produced by The Diesel Page since early 1996, many of which may no longer be available online. These reprint articles are available separately as part of a collection of bound volumes.
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Pro-Stock Duramax Diesel
Replay from 2007: Seemingly overnight, diesel drag racing has swept the nation, and is becoming more popular as each racing season passes. To help fill the need for speed, more retired Pro-Stock drag race trucks are being brought out of retirement, but not to run blown nitro burning bigblocks. Nope... The trucks are rocketing down the track with the state-of-the-art in diesel performance. Brad Makinen brought new life to a retired gas Pro-Stock truck in the form of "Dirtymax", a Duramax diesel powered Chevy 1500. This truck appeared at a drag race event I attended this past June here in Montana, which provided an opportunity to look beneath the fiberglass skin to see what it takes to make a Pro-Stock diesel run in the 8-9 second range.
Protecting Your Truck From Rust
Rust... Every year, millions of vehicles suffer many more millions of dollars in damage due to rust. As awful as the cosmetic damage is, rust can even make your vehicle unsafe to drive and you may not even be aware of it. I don't know of a single instance where someone dismantled their truck, sandblasted-stripped-repainted-recoated the metal parts and then reassembled everything to correct the damage caused by rust - just not worth it. What we'll do here is show you how to easily and inexpensively treat this rust problem. Now available to subscribers in the Member's Area. Not a subscriber? Visit this link to see how easy and inexpensive it is to become a subscribing and supporting member of TheDieselPage.com.
Do the Best Job Possible
In Part II I walk you through the process of replacing the Duramax water pump using the best tools, methods and parts. Everything you need is included... except maybe elbow grease. Do it right - learn how here. Now available to subscribers in the Member's Area.
GM's Next-Gen 6.6L Duramax
Beginning production in July 2000 with the 6.6L LB7 Duramax V-8 diesel engine, the current L5P 6.6L Duramax is the most recent and most powerful. Replacing the outgoing LML engine, the 2017 L5P incorporates a long list of advancements produced exclusively for General Motors' full-size heavy-duty (HD) Chevrolet and GMC pickup trucks. Go here for the specifications and all-important details.
We're here to save you money and provide the information you need to do the best job possible.
Own one of these trucks long enough and you'll eventually be faced with the prospect of replacing the original water pump. Normal cooling system pressure is in the range of 8-10 psi. The water pump's coolant-side seal is there to contain this pressure against a spinning shaft. Over time, this seal will wear until it begins to leak coolant. That's your cue for a need to install a new pump. What we'll do in this two part series is explain how to correctly identify a leaking water pump seal, give you a list of part numbers you'll need for the new parts, identify the special tools you'll need, and show you how to do the work using large clear photos and easy to follow instructions. In short, this professionally written water pump replacement guide should answer all of your questions.
Rocket science is a whole lot more entertaining when you actually get to drive one! The primary mission for this Duramax Diesel Power Project included proving that a Duramax 6600 diesel engine and Allison 1000 automatic transmission could be installed in a previous generation GM pickup truck, and then to explore the performance potential of the Duramax/Allison in a lightweight 4x4. Outside of General Motors, this truck was the very first Duramax diesel conversion in a pickup truck. Go here to see a series of fabulous photos of the completed truck.
and the GM Diesels
Updated for 2015: Operating a diesel engine during the cold winter months demands that all diesel fuel and electrical systems operate normally. Included here is list of precautionary measures and cold weather strategies that will help your diesel pickup operate reliably throughout the coming winter. If you're new to the GM diesel or any diesel light truck, the information found here should help to answer your questions as well as reduce any anxiety you might have about cold weather operation. Dealing with cold weather is really easier than you might think.
Front wheel bearings used in these 4-wheel drive 2500HD/3500 series pickup trucks are not serviceable. You cannot disassemble the hub bearing assemblies to repack them with high-temperature wheel bearing grease or to replace an individual bearing. The entire hub bearing assembly must be replaced whenever a bearing fails. Let's have a look at the symptoms of a failing hub bearing assembly, and learn how to replace one yourself. Now available to subscribers in the Member's Area.
This Truck's For Sale!
My 1984 C-10 Short-bed has served as a test-bed and project truck for a number of improvements in performance, and appearance since 1991. The best investment I ever made was joining The Diesel Page in 1996. This article is a summary of some of the projects undertaken on this truck, originally equipped with the light-duty 6.2L diesel, 700R4 transmission, and economy-oriented 2.73 rear axle gears. So, hoping to inspire the next generation to step up and take responsibility for keeping this 30-year-old senior citizen of the GM and Chevy diesel truck world on the road and representing the diesel heritage, I am reluctantly announcing that: My Truck Is For Sale!
Dual-Idler 6.5L Gear Drive Timing Set
This product review first appeared here in The Diesel Page in 1998. Many product reviews have come and gone since that time, and we sometimes forget just how important these can be to owners of the 6.2L and 6.5L diesels. Available for nearly 20 years, the Phazer Dual-Idler gear drive timing set for the 1994 and newer 6.5L Turbo Diesel replaces the stock chain-driven timing set and the original reluctor wheel used for the crankshaft position sensor. Advertising claims at the time said: "Our "Phaser" performance kit allows 3-5 degrees of timing advance right off the crankshaft, which we found to increase fuel economy, produces cleaner starts, and improves throttle performance." We'll install the Phaser, and independently test the ad claims.
Cast Aluminum Oil Pan for the Duramax 6600
Cast aluminum differential and transmission pans have been popular products among diesel owners for many years, but the engine oil pan has been largely forgotten by the aftermarket. Till now. A new lower oil pan was introduced recently for the GM Duramax 6600 by www.Go-Truck-Yourself.com. The Banana Pan was developed to allow a complete oil drain when changing the engine oil and make it easy to add an oil pan heater. The design of the stamped-steel sheet-metal OEM oil pan prevents 1 or 2 cups of old oil from draining at the time of service. The Banana Pan changes all that. Let's have a look.
Variety is the spice of life!
The 5.9L Cummins has to be the single most popular choice for a diesel conversion. Plentiful, relatively inexpensive, simple electrical requirements, enormous aftermarket support, proven reliability and a satisfying power potential all make the Cummins a popular choice. This month we present four 5.9L Cummins diesel conversions in four very different types of vehicles that demonstrate this popularity and versatility.
GM Re-enters the Light-Duty Diesel Market
Why now? We here at The Diesel Page have pushed GM to include a line of light-duty diesels for more than a decade. In 2001, GM, Ford and Dodge all had working designs in the pipeline for a fuel efficient common-rail diesel intended for the light-duty market. One by one, all of these light-duty diesels fell by the wayside. So why, after a dozen years of ignoring the clamor, is GM finally offering the Cruze diesel? Go here to learn more about the new Chevy Cruze.
The 1984 model year was a good one for General Motors despite the upheaval in the petroleum industry and a doubling of diesel fuel prices in the late 1970s and early 1980s. By 1984, the new 6.2L V-8 diesel engine had already been available for two full years, and reports were generally favorable. Buyers who needed a full-size pickup truck jumped at the opportunity to buy a GM model that offered twice the fuel economy of the carbureted gas 305 V-8. To see how it all began, let's have a look at a vintage 1984 GMC C/K Pickup brochure that illustrates what the General was offering new truck buyers back in the day.
The 2013s are here! Go here for all of the new truck details.
At the time of rebuild, a percentage of 6.2/6.5 block decks must be resurfaced because of wear caused by the head gasket's fire ring. The removal of a few thousandths is usually enough to clean up the deck surfaces, which also produces a clean and flat surface for the new Fel-Pro gaskets to seal against. If the machine shop is doing its job, the machined surface doesn't need any further hand preparation. Otherwise, a flat sanding block and 80-grit paper can be used to carefully prep the deck surfaces when not re-machining the decks. Milling the block deck changes the piston protrusion, requiring the use of thicker head gaskets. We show you how to measure piston protrusion and how to choose the correct head gaskets. Now available to subscribers in the Member's Area.
USDP's sixth annual Dyno Day was held this past June 2, 2012 here in Missoula Montana, and the crowd just keeps getting bigger each year. From morning till late afternoon, 3 dozen of the Big Three's diesel pickups rolled across the Mustang dyno rollers and kept everyone entertained.
1999-2007 Power Window Regulator Service
I was buzzing the driver's side window down a short while ago in my 2001 GMC 2500HD, and I heard a gritty/grinding sound and noticed that the window wasn't moving normally. Hmmm... So, I moved the window button in the opposite direction. It was then that I heard a pop, like a pea sized chunk of gravel pinging off the windshield at highway speed. The window stopped moving, then began a slow slide downward. The window had become disconnected from the mechanism that moves the window up/down. This mechanism is called the window "regulator". Not a good start to the day. Go here to see an illustrated guide to replacing the power window regulator. Now available to subscribers in the Member's Area.
Getting the Proper Fit
Crankshaft bearing selection is vital to produce the correct running clearances for the crankshaft's main and rod bearings. When correctly assembled, there are always a few thousandths of an inch clearance in rod and main bearings. This clearance provides room for an oil film to act as the actual bearing. This series of related articles discussing the assembly of a newly machined 6.5 block hit the highlights of an engine assembly so you can better judge for yourself whether you're equipped for such an endeavor. The photos and information contained in this series also provides essential information for which you can judge the knowledge possessed by your chosen engine rebuild shop. Now available to subscribers in the Member's Area.
Getting the Proper Fit
Learning how to use micrometers and bore gages is critical to correctly fitting pistons. This month's 6.5L engine rebuild series update discusses how I measured both pistons and cylinder bores, and shows how you can do this as well. While learning how to use these tools takes time, what follows is a primer for measuring the bores & pistons. Go here to see how it's done. Now available to subscribers in the Member's Area.
Duramax Diesel Conversion
I always enjoy hearing from others who have completed or are beginning a Duramax conversion. A few months back, Jason contacted me with a few questions about his recent conversion project. Our discussion may help shed some light on a similar conversion you might be considering. Now available to subscribers in the Member's Area.
With a problem...
It's been a couple of years since Russ Newton acquired a 1997 6.5L diesel K2500 Suburban, and it's taken this long to return it to good condition and get it back on the road. Russ sunk what he described as an "insane" amount of money into the Suburban for a complete and professional paint job. The results are fantastic. One problem remained after all that work - an annoying vibration. Read along as Russ and I discuss the possible sources of vibration. Now available to subscribers in the Member's Area.
What would I do differently if I were to begin another 6.5L Turbo Diesel Power Project? I've been asked that question many times over the past decade, and I answer by saying "I wish I had experimented with different turbochargers." Not until the end of the project did I come to realize that the factory GM-8 turbocharger was a performance-limiting problem. We're always learning, and since the early 2000s we've produced several articles discussing how the various turbochargers we've learned more about might improve 6.5L performance. As of 2012, this update reflects current thinking. Now available to subscribers in the Member's Area.
Power Starts Here
Own a vehicle long enough and you'll eventually have to replace the batteries. All GM 6.2/6.5/6.6 diesels came from the factory with two hi-capacity automotive batteries, wired in parallel to double the amperage capacity. This higher capacity is necessary because the 6.2/6.5/6.6 glow plug system and intake pre-heater used in the Duramax put a big load on the batteries during a cold start. And, these diesels are high compression ignition engines that require more power to crank. The combustion heat generated during the compression stroke is what ignites the diesel fuel, and a faster cranking speed increases the heat. Knowing this, it's no surprise that diesels start easier with a faster cranking speed. Let's have a look at the choices we diesel owners need to consider when buying a replacement set of batteries and look at how to prolong the life of the batteries we already own. Now available to subscribers in the Member's Area.
Getting the Proper Fit
I've not recommended most owners get involved with doing their own bearing/piston fitting because of the KSAs (Knowledge, Skill & Abilities) and tools necessary to do it correctly. I still don't know whether it's a good idea for most of us (yes, I'm including myself in this category), but our current 6.5TD project may change that opinion. However, because the current 6.5L Turbo project requires me to fit both bearings and pistons, this may provide an excellent opportunity to dig deeper into the subject, and it'll allow learning something new that The Diesel Page has not covered before. Whether you do the work yourself or you're an involved sort of person who wants to check the work of your local machine shop, the information presented in this series will help you sleep better. Now available to subscribers in the Member's Area.
This article first appeared here in The Diesel Page in 2002, and we've been asked to reintroduce the story to all those members who may have missed it the first go-around. A talented engine machinist and performance enthusiast creates the ultimate in electronic 6.5L diesel performance. Roller valve rockers, steel block girdle, deep aluminum oil pan, custom turbo & intercooler and many other custom features are combined into one engine that proves itself on the chassis dyno. Now available to subscribers in the Member's Area.
We owned a 1994 6.5TD Chevy Blazer more than 10 years ago. This was a fun and reliable vehicle, but we let it go too soon. Though it's gone through a couple of owners since, that very same Blazer has found its way home... The engine is currently in pieces, but that's a good thing. This will provide an opportunity to build an electronically fuel-injected 6.5L in a direction we haven't explored before. This will also provide you with an opportunity to participate in designing the Project - engine build direction, end goals, and so on... Should be fun, and it'll provide answers to questions that haven't been covered before. Now available to subscribers in the Member's Area.
Solving Contamination Problems
A $4500 out-of-warranty Duramax injector replacement bill usually gets people thinking about fuel quality and its direct correlation to injector life. What we'll do here is discuss what we as diesel owners need to be aware of when buying fuel and learn how to deal with most fuel quality problems. Whether water, gasoline, sediment, or biological contamination - solving a fuel contamination problem is never any fun, but knowing with certainty what to do if it happens will provide a sense of security. Print this page and keep it in your truck's glovebox. You never know... Now available to subscribers in the Member's Area.
Fuel Lift Pump Circuit
A member and owner of a 1998 6.5TD called recently with a fuel lift pump problem that was a bit confusing. He reported that he had recently replaced the lift pump and the oil pressure switch, but the pump would not function. Hmmm... So, I dug out the schematics and we discussed over the phone about how the fuel lift pump circuit should function in the 1996+ GM trucks. Here are the results of our discussion. Now available to subscribers in the Member's Area.
The tailgate on my truck refused to open recently due to a failure of one of the latch components. Solving the problem allowed for an indepth look at the latch and hinge components. What follows here is a step-by-step guide showing you how to service the tailgate and keep it functioning for years into the future. Servicing the latch and hinge components every year or two will keep them in fine shape and will help to prevent rust. I've neglected mine for far too long. Now available to subscribers in the Member's Area.
Eleven Steps to Success
These GM trucks have eleven grease fittings on the front-end. GM recommends greasing these eleven fittings at every oil change, which can vary from 3,000 miles to 7,500 miles, depending on how the truck is used and under what conditions. What we'll do here is suggest a type of grease and grease gun, and show you where all of the fittings are and how to grease them. Now available to subscribers in the Member's Area.
Renewing Plastic Lenses
It seems today that vehicles are utilizing more plastic than ever before. Care of plastics presents unique challenges that many of us are not immediately accustomed to. After finishing eight years of continuous sea duty in the U.S. Navy, I decided that now would be a good time to invest more effort in vehicle maintenance. In researching ways to improve the appearance of my Suburban's taillight assemblies, I turned to Griots Garage to assist in that goal. Follow along as we show just how easy it is to return your plastic lenses to like new condition.
Frequently Asked Questions
It's been a few years since we updated this page, but the engine evolution hasn't been static. A number of questions are answered here that have become the most frequently asked. Such as: What was the genesis for the Duramax 6600 diesel engine, and who builds it? The Duramax has evolved through time. How many different generations now exist, how can I determine which version I have, and how are they different? What are the GVW ratings for the new 2001-2005 2500HD/3500 pickup trucks? What are the trailer weight (towing) ratings for the new 2001-2011 HD trucks? Does the Duramax really offer "class-leading" performance? When will GM produce a new diesel Suburban? These questions and more are all answered here.
3G Mobile Broadband Hotspot
I envy those who live in areas supported by digital cable, DSL or another wired high-speed Internet service. While Montana offers many lifestyle advantages, one deficit is access to high-speed Internet, especially those who live outside the primary coverage areas. Nearly everyone finds The Diesel Page through the Internet. Anything that makes access easier is better for everyone, and the Verizon Wireless Fivespot hotspot provides instant broadband Internet access to The Diesel Page both at home and while traveling. I believe the new Verizon Fivespot is a worthwhile addition to your diesel tool box. Let's have a look at it.
Where to begin?
Where there's a will, there's a way. In this economy, more of us are finding the will to work on our out-of-warranty trucks. This month, we'll begin that process by helping you prepare - discussing what parts and supplies you'll need, as well as establish some basic guidelines for working inside your engine. Now available to subscribers in the Member's Area.
The serpentine belt tensioner is a wear item that will need to be replaced - eventually. I recently replaced a noisy belt tensioner on my 10-year old 86,000-mile 2001 GMC. I suspected either the pulley bearing was on the verge of failure or the tension hub had become worn - it was producing a rattling sound that indicated it was not long for this world. For either type of problem, replacing the belt tensioner with a new one is the best cure. While replacing a tensioner isn't all that difficult, what appears here are a few tips that can help you do the job correctly. Now available to subscribers in the Member's Area.
More than a million Duramax powered pickups are now out of warranty. The cost of dealer service can sometimes be beyond what many owners are willing to spend, but they are willing to perform more of any required maintenance themselves. Doing the work correctly requires a proper use of hand tools, and correctly torquing the fasteners during re-assembly is absolutely vital. In addition, much of the engine is made from aluminum, which requires all of us to take precautions when re-assembling the engine to avoid stripping the threads. Stripped threads will turn a relatively routine job into a real pain. That's where a comprehensive torque specs sheet comes in. Now available to subscribers in the Member's Area.
Improving Diesel Fuel Economy
Hydrogen gas has been used to augment diesel fuel for many years, proving it can both extend the driving range between fillups and increase average fuel economy. Here's a hydrogen gas generator specifically developed for use as a motor fuel supplement.
Gear Drive Timing Set & Fluidampr
A long-time member recently upgraded his 1997 6.5TD Chevy Tahoe with a gear drive timing set and a Fluidampr. Aside from showing William's upgrades and installation, this also presents another opportunity to talk again about what benefits these upgrades may provide. Now available to subscribers in the Member's Area.
Helping them do a better job!
From 1985 through the early 1990s, GM incorporated the Stanadyne Model-80 diesel fuel filter assembly into its 6.2L diesel-equipped pickup trucks and SUVs. In addition to a Water-In-Fuel (WIF) sensor and fuel heater, the Stanadyne Model-80 fuel filter assembly also included a fuel restriction sensor. Unfortunately, many of these restriction sensors eventually began to leak fuel. Also included is a discussion about the 1990s Stanadyne Fuel Manager fuel filter assembly that was a part of the 6.5's fuel system. Now available to subscribers in the Member's Area.
Here at The Diesel Page we've not gone into much detail about engine rebuilding because the required knowledge and access to specialized equipment are beyond most of us. We've recommended you locate a local engine rebuilding center near where you live, and use them to do your diesel engine rebuilding for you. Being local allows better communication between yourself and them, and they may be more conscientious in trying to satisfy a local customer. However, it appears more individuals nowadays are getting into the rebuild process - some to save money and some to get a better result. Saving money and getting a better engine are good things. Now available to subscribers in the Member's Area.
GM Diesels Worldwide
A diverse range of GM diesel powered light-trucks and autos can be found in significant numbers all over the world - except here in the United States. Many theories have been discussed through the years concerning why there is a dearth of domestic diesels, but I'll attempt to explain why this situation exists and (to tease the membership) show you some of the GM diesel powered vehicles you've been missing out on. Now available to subscribers in the Member's Area.
DAYTON, Ohio - DMAX Ltd., a 60-40 joint venture between General Motors Co. and Isuzu Motors Ltd., today celebrated 10 years of making award-winning diesel engines. In ceremonies attended by community and government leaders, company officials marked cumulative production of 1.2 million engines since July 2000. DMAX is the exclusive manufacturer of the award-winning Duramax diesel engine that powers Chevrolet Silverado and GMC Sierra heavy-duty pickups and Chevrolet Express and GMC Savana full size vans.
1997 K2500 Suburban 6.5TD
I've come to the conclusion that I need some experienced advice on what to do and in what order to make my truck what I want it to be. I searched for at least 5 years before I found this truck, as I was missing my 1995 5.7 Suburban so much, but always wanted a diesel. The truck was a surplus sale from the fire & rescue department of the city of Sunset, Florida (Ft. Lauderdale). At least I had a good starting point. I'm on a quest to upgrade and restore the rest of the truck to set a higher standard for itself, and would appreciate any advice you could provide. Here are a few of the known issues the truck currently has that need a remedy... Now available to subscribers in the Member's Area.
The Economics of Repairing/Upgrading/Customizing
For most people, once the cost of repair exceeds ½ the current value of that vehicle, the repair cannot be economically justified. It's time to trade. On the other hand we also know that there are considerations beyond economics, and that many GM diesel owners sometimes spend more than what the economics alone would suggest is reasonable. Let's have a look at vehicle repair and upgrade costs, and from an enthusiast's point of view, illustrate some points you may not have considered. Now available to subscribers in the Member's Area.
Tips on changing a flat tire!
I remarked recently to couple of diesel owners that it had been 30+ years since a truck I was driving experienced a flat tire. How quickly it all changed recently. The spare tire had never been off the truck and I had never removed the jack and tire tools from beneath/behind the rear seat. Getting the tire changed, as it turned out, was not a big deal. Here's a step by step guide to changing a flat. Now available to subscribers in the Member's Area.
It's entirely possible to replace an ailing 6.5 with a good running 6.2, but there are a few "need to know" details that will make the swap easier and perform more reliably. The 6.2 and 6.5 share the very same basic architecture and accessory mount requirements. This means that, other than a few details discussed here, you will be able to replace any model year 6.5 with any model year 6.2. The military application for these engines have created opportunities to acquire a replacement engine without spending a lot of money, which has increased the interest level in swapping a 6.2 in place of a 6.5. Let's show you how it's done. Now available to subscribers in the Member's Area.
Model Year Comparison
We get questions nearly every day from used truck shoppers asking what year Duramax is best. With the new 2011 model year arriving in mid-2010, we now have five different generations of the engine and two generations of the Allison automatic to consider. Which model year is the best buy? Which truck is most reliable, and what sort of problems have these trucks had? Which engine/transmission combination is most reliable, and which produces the best fuel economy? And finally, which model-year offers the most power? Compare them all right here. Now available to subscribers in the Member's Area.
13-Second 6.5TD Race Truck
For most of the past 8-10 years, nearly all of the diesel performance news has been about the Duramax, the Cummins and the Powerstroke. The 6.5L diesel engine may not have been designed to compete at the track, but it has a whole lot more potential than many believe. Just as in the world of competitive auto or motorcycle racing, track events are an excellent venue to force the evolution of engines and performance products. Some of these developments trickle-down to the typical vehicle owner who is simply looking for perhaps a modest bump in performance or to improve reliability and longevity. Here's a good-news story about 6.5L Turbo Diesel performance that includes an in-depth look at what it takes to run in the 13's. Now available to subscribers in the Member's Area.
A 2005 GMC Goes The Distance!
Imagine driving your truck 400 miles today, 400 miles tomorrow, and 400 miles every single day for the next 5 years (that's 1825 days). If you did, your Duramax would have what this truck has - more than 750,000 miles on the odometer. Do we know how long can the Duramax can last when used to tow?
What GM Should Be Building!
After creating a dozen or so essentially new Duramax powered HD Suburbans, an Ohio Duramax enthusiast recently began a 2010 Chevrolet Suburban LTZ HD project, which will be equipped with a 2010 LMM Duramax 6600 and 6-speed Allison automatic. These are the vehicles GM should be building. Now available to subscribers in the Member's Area.
This past February 4th, and we learned all about GM's plans for the 2011 model year GM 2500HD/3500 series pickups. Though we're expecting a price increase of $3,000-$5,000, due to the addition of the "Diesel Exhaust Fluid" (urea) system, GM is back with a range of improvements and upgrades that promise to make GM the HD diesel truck leader. Go here for all of the new truck details.
Engine & Emissions Tech
The 2010 emissions regulations are upon us - as well as GM. Here's an indepth look at the new 2011 LML Duramax 6600 and the new emissions equipment. How's it all work? What effect will it have on ownership? What else is new & different about the Duramax? We'll answer all these questions and more.
The roots of the Automotive Engine Rebuilders Association goes all the way back to 1922. With over 3,000 current members worldwide, the AERA has focused on member service through its publications, the web and in meetings and seminars. Networking on a professional level allows its members access to the best and most up-to-date engine service information, which can result in the best overall vehicle owner satisfaction. Diesel engines have always been a part of the AERA's program, and some of the best 6.2/6.5 problem-solving information originated with the large network of AERA member techs. Here's a run-down on a selection of 6.2/6.5 related AERA bulletins that we've referred to here in The Diesel Page quite often. Now available to subscribers in the Member's Area.
The chaos in the economy, the uncertain political climate and the trials GM has had these past 12 months have produced a flood of rumors on the Internet and certainly among the GM diesel community of pickup owners. Is the Duramax on borrowed time? Well.... for the time being no, but there have been a number of curious events that could cause one to believe that. This editorial discusses what I've heard, and despite the big hole in production, smart money expects the newest LML urea-equipped Duramax 6600 to appear in the 2011 model lineup. Go here for the details. Now available to subscribers in the Member's Area.
Diesel engines are hard on head gaskets. No matter how well the gasket may have been designed, replacing the head gaskets can be an issue a longtime diesel owner may need to deal with. The Duramax was designed to produce a compression ratio (CR) of between 18:1 to 16.8:1, depending on model year. Add the high CR (compared to a gas engine) and the high power/torque output of these engines, and you know cylinder pressures are high. What I hope to do here is describe what symptoms appear when a head gasket or an LB7 injector cup begins leaking, which usually results in excessive cooling system pressure or a loss of coolant. Knowing what to look for can save you a lot of money if the problem is caught early, and taking care of the problem before it becomes worse can reduce both downtime and overall expense. Now available to subscribers in the Member's Area.
Here is a story about a Duramax 6600 diesel powered Massey Ferguson tractor owned by Lammert ter Heide, here in Holland. This is not the first GM diesel to power this tractor. Before the Duramax, Lambert powered his Massey with a 6.2L turbo diesel. More is better, so installing a Duramax promised to take the power to a new level, and make it very competitive during the popular tractor pulls now sweeping Europe.
for the 6.2L Diesel
We've been discussing the Holset HX35 here at The Diesel Page for quite a while now as a potential improvement in turbochargers over what is possible when using the GM-x series of factory turbos. Member Tyler Nelson has installed an HX-35 on his 6.5L diesel that is currently installed in his 1986 CHevy K10. Tyler's installation broadens the application of this turbo to include all 6.2/6.5 diesel engines in the 1980's body style trucks and Suburbans. Now available to subscribers in the Member's Area.
Twin 6.2L Diesel Powered - Chris Craft Commander
Lucky Max is a Chris Craft Commander (Sports Cruiser model) built in Michigan in 1972. She is 31' long and approx 10' wide. The hull is fiberglass, constructed before the folks really knew the true strength of fiberglass. This means that the material is thicker that what you might find on a boat built today, but also, I believe it was all "hand-laid" at that time. I have not yet been able to confirm weights, but I've been told that the boat would probably scale around 7 tons.
Making the Dirty-Side Look Good
Member Andrew Prince wrote recently to provide information concerning how he applied some rust prevention to his new truck. As some of you may recall, The Diesel Page produced an article in 2004 entitled, "Room for Improvement", which included some shots beneath the new trucks that showed far too many rusted components. In that 2004 article, we said "A certain segment of the Duramax powered 2500HD/3500 truck buying group is comprised of enthusiasts - those who obsess to some degree over the look, ride, utility or performance of their new truck. Including myself as part of that group, I've winced at certain details of the new trucks. GM could easily rectify the situation, and this article is intended to highlight some of what I feel needs attention." While there have been a few improvements made since 2004, with regard to rust control, more needs to be done. That's what this article is about.
Adding Air Flow Performance - Inside the Cab!
1999-2002 GM Full-Size Pickup Trucks
Has the cooling efficiency of your truck's air conditioning system gone down hill in recent years? Does the inside of your truck smell like wet socks when it's damp outside? If so, maybe you need to replace the in-cab "Passenger Compartment Air Filter". One of the least talked about routine maintenance items is the passenger compartment air filter. Factory installed in the 1999-2002 GM full-size pickups, the in-cab air filter(s) was designed to trap dust, pollen, and other debris that might enter through the vehicle's fresh air vent system. In addition to making the in-cab environment a more pleasant place to spend time, filtering the air also helps to keep the A/C evaporator core and heater core functioning normally. We'll show you with large and clear photos how to easily replace the in-cab air filter. Now available to subscribers in the Member's Area.
Reprinted from The Diesel Page - February 2001
This tech page first appeared here in The Diesel Page in February of 2001. After analyzing the various wiring diagrams and theory of operation for both the 1991-1993 DB2-equipped 6.5 trucks and comparing that information to the 1994+ 6.5TD equipped trucks, an idea was born that I thought might help those truck owners who wished to convert their DS electronic trucks to use a DB2 mechanical fuel injection pump. We knew going in that maintaining shift quality for the 4L80-E would be the biggest challenge following a mechanical fuel injection conversion. This tech page is being re-printed here to show what we did more than 8 years ago, and perhaps spur additional thought. In addition, new and expanded information has been added that outlines what alternatives are available for 4L80-E control. Now available to subscribers in the Member's Area.
USDP's third annual Dyno Day was held this past June 6, 2009 here in Missoula Montana, and the crowd just keeps getting bigger each year. From morning till late afternoon, 42 of the Big Three's diesel pickups rolled across the Mustang dyno rollers and kept everyone entertained.
2500HD/3500-Series Pickup Truck & Duramax Specifications
Pickup trucks and large sport utility vehicles have been GM's most profitable automotive segment. Pickup truck sales accounted for just 1% of the total automotive sales volume in 1959, while trucks (pickups & large SUV's) totaled 64% of GM sales in 2005. Due to their enormous popularity, pickups aren't going away anytime soon, and the Duramax Diesel will remain a big factor in driving pickup sales.
Do you really need to install a performance exhaust system before adding power?
Does an aftermarket exhaust system really make a difference in dyno or towing performance?
Real-life testing is the best way to answer these questions.
Product Review: Factory exhaust systems have improved considerably though the years, with mandrel-bent 3-1/2" or 4" tubing now being the norm. You've probably read quite a few exhaust system reviews through the years, and saw the rear-wheel horsepower improvement following the installation of a performance exhaust system. The installation photos were nice and the dyno numbers usually reinforce the notion that an aftermarket exhaust system allows the engine to make more power and help to provide a safety margin when installing performance products. What's the real story?
GM revises the factory gasket
As is typical for any production engine, the manufacturer can introduce design changes throughout the production life as experience is gained through warranty repairs. GM recently released the most recent upgrade in cylinder head gasket design as well as new head bolt torque specifications for the LB7, LLY and early LBZ engines. The second-generation head gasket will require a new lower head bolt torque angle specification as well as special cleaning methods for the head/block gasket surfaces. Go here for all of the details. Now available to subscribers in the Member's Area.
Model - T50e
Product review: Being able to read and erase trouble codes is a basic necessity these days - especially for anyone owning a GM diesel truck that is out of warranty. Even if your truck is still covered by the factory powertrain warranty, knowing what that "service engine soon" light means and how serious the problem might be can help you when scheduling service or can help you gain some insight into what the problem might be. The inexpensive T50e can can help you save money on vehicle maintenance.
Step By Step Procedure
To promote goodwill and maintain the reputation of the Duramax 6600, GM offered a generous 7-year or 200,000 mile injector replacement warranty to all LB7 owners. This was good news to those owning 2001-2004.5 Duramax equipped truck, and the extended warranty did save a lot of owners a lot of money on injector replacement. But, all that has already or will soon be coming to an end. The first LB7 Duramax powered trucks are coming up on nine years old. The first two model years for the Duramax are now past the 7-year time limit, and those owners have to bite the bullet and pay for any injector replacement out of their own pocket. For the past thirteen years The Diesel Page has been here to help members save money on engine service, and that's why we're presenting this do-it-yourself fuel injector replacement tech story. Now available to subscribers in the Member's Area.
Marine vs On-Road
A lot has been said in recent years about using marine fuel injection system components for an on-road 6.5L turbo diesel application. For those who may not know, connecting the word "marine" with the GM 6.5L diesel began with the development efforts at Peninsular Diesel. Specially calibrated marine fuel injectors, marine fuel injection pump calibrations and marine oriented turbochargers all came from the "boat" point of view at Peninsular. A marine 6.5L diesel must be equipped to cruise at approximately 2600-2800 RPM for extended periods of time, and make efficient power at those engine speeds. Not coincidentally, Peninsular's marine 6.5L turbo diesels produce maximum torque and deliver an efficient fuel consumption rate at that same RPM range. It's all about the torque peak... To work with the marine paradigm in engine speeds, the fuel injection system must meet the needs of the engine RPM (and of course, meet the expectations of the boat owners). Here's what we know about marine 6.5L fuel injectors and marine fuel injection pumps. Now available to subscribers in the Member's Area.
Power, Load & RPM
How do these factors affect diesel fuel economy?
We've been telling folks for years that in general, a diesel engine produces its best fuel economy when run at or near the RPM that coincides with its torque peak. Whether you're towing a heavy trailer or simply commuting to work, the torque peak RPM is where you'll find the best fuel economy. In June 2006, we dyno tested a new 6.5L "Fuel Mizer" fuel economy engine using Peninsular Engine's calibrated fuel metering and engine dynamometer system in hopes of confirming that fact. Now available to subscribers in the Member's Area.
Spring 2008 Dyno Day
After a long winter here in the Northwest U.S., most diesel pickup owners are ready for a trip to the Southwest - Southwest Canada to be precise, the home of BD Diesel Performance and their semi-annual Dyno Day. Despite the gray skies, hundreds of diesel enthusiasts made their way to Abbotsford, British Columbia last spring on April 5th, and a total of sixty trucks spun the rollers from early morning through late afternoon. If you like power, this was a great way to spend a day, to both learn more about diesel performance and have an opportunity to see trucks push the Mustang dyno to nearly 1000-hp.
Duramax Diesel Conversion - In Progress
Bringing new life to an older truck is more than just a way to save a ton of money. A surprising number of members keep the same vehicle for decades, and want to do all they can to keep it on the road. Converting the drivetrain to Duramax/Allison power has become a popular upgrade for the GM fans, which increases the vehicle's capability. Member Kean Clark is currently working his way through a 1987 Chevy C30 restoration and Duramax conversion project, and we wanted to share his progress with the GM community.
Synthetic/Conventional - Which is Best?
Important Facts About Motor Oil
The question of whether we should be using synthetic diesel motor oil in our GM diesel engines has been a popular subject for a long time. Synthetic oil has some definite advantages over the available conventional motor oils, but are there any measurable benefits that justify the added expense? Find out here! Now available to subscribers in the Member's Area.
HX-35W Turbocharger Installation
The Holset HX-35W has been discussed here in The Diesel Page as an alternative to the factory GM-series of turbochargers - for the performance oriented 6.5 owner. Member Jerry Giedeman dropped by recently to show me his 1994 light-duty K2500, and discuss a few of his engine modifcations. Included among those modifications was the installation of an HX-35W turbocharger. Follow along as we show you Jerry's turbo setup and explain how it was integrated into his overall 6.5 performance plan. Now available to subscribers in the Member's Area.
Annotated Diagnostic Trouble Code List
This annotated Diagnostic Trouble Code (DTC) list is specific to the Allison 1000 automatic transmission. Being armed with a good basic knowledge about the Allison trouble codes can help to ensure a better level of service if you have an in-warranty truck or can save you a lot of money if your truck is now out of warranty. Now available to subscribers in the Member's Area.
Annotated Diagnostic Trouble Code List
This annotated Diagnostic Trouble Code (DTC) list contains all of the Duramax diesel engine-specific trouble codes relating to the engine. We've learned through the years that while a typical GM service technician may understand gas engines and their related powertrains quite well, a talented diesel mechanic is much harder to find. Being armed with a good basic knowledge about the diesel systems incorporated into your truck can help to ensure a better level of service if you have an in-warranty truck or can save you a lot of money if your truck is now out of warranty. Want to know what the codes are, what they mean, how to retrieve them and know how to repair the problem? Now available to subscribers in the Member's Area.
Troubleshooting & Maintenance
Back about the time the auto makers began using electronic fuel injection, they discovered that for the onboard computer to correctly calculate the fuel/air ratio, they needed to measure the incoming air flow to the engine. Electronic fuel injection not only allowed the engine to run more efficiently and to produce better fuel economy and drive-ability, but MAF sensor data also allowed the computer to help protect the engine if the ratio of fuel to air fell outside of normal. The Duramax diesel also employs a MAF sensor, which is used to measure the grams/second of air entering the engine's intake system. Now available to subscribers in the Member's Area.
AM General's New P400 6.5L Turbo Diesel
Turning Up the Pump for More Power!
The new and redesigned AMG P400 6.5L Turbo Diesel first became available this past March 2008. Mike Robertson bought one of first, and has installed this engine in his 1993 Chevy K3500. We'll show you what was involved when installing the engine, how it is equipped and we'll show you the dyno data that demonstrates the performance improvement after some minor tweaking of the factory fuel injection system. Now available to subscribers in the Member's Area.
Accelerator Pedal Position Tech & Troubleshooting
The 2001 model-year and newer GM Duramax diesels were all equipped with the "drive-by-wire" Bosch high-pressure common-rail electronic fuel injection system. While the Accelerator Pedal Position (APP) module has performed reliably through the years, the first Duramax equipped trucks are now more than 8 years old, and knowing how the APP operates and how to troubleshoot a problem could be a huge help in the future. Thirteen diagnostic trouble codes are discussed, and we'll walk you through the troubleshooting process. Now available to subscribers in the Member's Area.
GM's Suburban Goes Diesel
Those of us who have been following GM's on-again off-again diesel Suburban program over the past eight years were beginning to lose faith whether we would ever see a production version. The wait may be coming to an end as GM unveiled its proposed 4.5L Duramax powered Suburban to an enthusiastic crowd during last fall's annual SEMA show. The most recent news we have is that GM will begin production of the 4.5L V-8 sometime in the second half of 2009 (as a 2010 model year), and will introduce this new engine in a variety of full-size vehicles, including the popular Suburban. Go here for more engine details. Now available to subscribers in the Member's Area.
Cylinder Heads & Ricardo Comet
This article was first written in May 2006 when diesel fuel cost just $2.90/gallon. Following hurricane Katrina in 2005, GM diesel owners became increasingly concerned about the $3/gallon diesel fuel we experienced as a result of the storm. In an effort to help owners better understand the 6.2/6.5 engine design and to provide a little insight into how to improve fuel economy, we discussed cylinder head and pre-cup design. Fast forward to mid 2008... Now that diesel fuel has reached $5/gallon in some parts of the country, we've reloaded an expanded version of that 2006 article, to provide even more information that explains how to squeeze more fuel economy from your GM 6.2/6.5 diesel. Now available to subscribers in the Member's Area.
Amsoil Dual Bypass Oil Filtration
Product Review: A dual-bypass oil filtration system and synthetic motor oil can extend drain intervals by at least 8 times when compared to conventional oil and filters, and can extend the life of your engine. Follow along as we show you how to install Amsoil's Dual By-Pass oil filteration system and show you the analytical results of cleaner oil.
GM's Locking Diesel Fuel Cap
All those who haven't been living under a rock have probably noticed that the cost of diesel fuel has risen to the "Arm & Leg" level at your neighborhood fuel station. You have to know that the "five finger discounters" have also noticed. Save money on your fuel costs by buying a genuine diesel locking fuel cap directly from your local GM dealer. Go here for the installation instructions. Now available to subscribers in the Member's Area.
Why is Diesel Fuel Higher Priced Than Gasoline?
Energy Independence & Affordable Diesel Fuel
This editorial is the result of a conversation we were having in our bulletin board forum about exporting diesel fuel and high diesel fuel prices, which motivated me to dig deeper into our nation's energy policies and use of petroleum. What I learned is that time is running out. Aside from the opinions expressed, this editorial catalogs what conventional and unconventional oil sources currently exist here in the United States. Almost everyone believes that becoming energy independent is vital to the future of the country. How much oil are we using? How much is the world using? How much are we paying for imported oil, and how long can we continue to pay? Do we have the will to become energy independent? Do we actually have a choice?
Leveling the Load
For the 1992-2008 GM Trucks & Suburbans
Like many of you who use your diesel pickup truck or Suburban to tow trailers or haul heavy loads, I use my Suburban to tow a 30 foot travel trailer that tips the scales at a hefty 8500#. Over time, this has caused the rear springs on my 3/4 ton Suburban to relax so that the rear now sits lower than the front even while unloaded. With models available to fit all 6.5L or Duramax powered pickup trucks and Suburbans, I eventually settled on the AirLift adjustable air springs as being the best solution to this problem. Follow along as we take you through the kit introduction, installation and show how the air springs solved the problem. Member's Area.
Excessive Fuel Return Flow & Related DTCs
P0089 - P0093 - P1093
The Diagnostic Trouble Code P0093 applies to the 2001 model-year Duramax. This trouble code was updated for the 2002-2004 model year engines, and received a new number - P1093. Each refers to the same problem. P0093 & P1093 are defined as "Fuel System Large Leak Detected", which could mean that one or more injectors are experiencing a high fuel-return flow rate. People usually start looking beneath the truck for signs of fuel, but this isn't that kind of a leak. Let's have a look at these, and other related trouble codes, to provide a little more insight into what they mean and how to deal with them. Available to subscribers now in the Member's Area.
Low Fuel Supply Pressure Due to Excessive Fuel Return Flow
Not many "new" 6.5L diesel problems come to light these days. After twelve years, we've seen just about every problem these engines and fuel systems can experience. A few months ago one of our Hawaiian members called to report a problem he was having with his DS4 equipped 6.5 that I had not dealt with before, and I thought it was interesting enough to discuss here in The Diesel Page. That problem is excessive fuel return flow and low fuel pressure developed by the electric fuel lift pump. Available to subscribers now in the Member's Area.
Transfer Case Leak Prevention
For several years now, we've been hearing reports of transfer case fluid leaks due to a wear-through on the rear case half. If not caught before a leak develops, the transfer case could suffer complete failure due to a lack of lubrication. The most reliable solution includes installing an aftermarket part that prevents a case wear-through from happening. Follow along as we show you the problem and describe what it takes to produce a permanent solution.
Improving Cooling System Performance for the 6.5L Turbo Diesel
The new 130-GPM water pump increased coolant flow through the block and heads by 74%, and through the radiator by 9%. The motivation for increasing the coolant flow-rate was to help eliminate hot spots within the engine and to reduce cylinder head cracking. Dual thermostats were required to both increase the flow rate capacity and to prevent pressure surges within the cooling system that are possible when running a single thermostat. We learn more from GM employees about why we need dual thermostats when running the 130-GPM water pump.
for the 6.5L Turbo Diesel
For decades, splayed main caps have helped power merchants in the gas engine performance market provide a solution to cylinder block failures. Multiplying the power output of a factory engine can stress the block in ways the original engineers never imagined. Splayed main caps anchor the main webs to the pan rails, which help strengthen the bottom end and allow the engine to safely produce a lot more power. Since 2002, custom engine builders have begun adding them to the 6.5L diesel, not so much to make big power, but to reduce the possibility of main web cracking. Let's have a look at three different aftermarket splayed main cap designs for the 6.5L diesel, and consider what they might do to improve 6.5 reliability. Available to subscribers now in the Member's Area.
Improving 6.5L Durability
The 18:1 Peninsular pistons were incorporated into our project 6.5TD engine build in late 1998. The advantages of a lower compression ratio (in the context of the project engine) is, a lower CR allows for more boost, and more boost allows for more fuel, which means the engine will make more power, while maintaining reasonable combustion temperatures & pressures. The folks at Peninsular Diesel told me they use a lower CR for the durability advantage. This is an expanded explanation for why lowering the compression ratio improves durability and what effect lowering compression might have on engine operation. Available to subscribers now in the Member's Area.
What's the real story?
Knowing what to expect when buying performance products for your 6.5 should be a part of your shopping experience, and advertised power gains should be reflected by those seen during real-world tests. Though individual trucks and powertrains can produce some variability in the power they produce with a particular vendor's performance programming, the averages should reflect reality. This article is presented here to provide a historical perspective on 6.5 power going all the way back to 1997 (yes, we've been doing this a long time), and to provide a reality check for advertised performance gains. Available to subscribers now in the Member's Area.
Identifying Genuine AMG Cylinder Blocks
The rising popularity of diesel pickups in recent years has created an uncounted number of new markets and new opportunities for both manufacturers and vendors. Even the 6.5L diesel has seen its popularity increase among both diesel owners and the aftermarket. This rising popularity is mostly positive, but it does have a darker side - counterfeiting... Find out how to identify genuine AM General 6.5L diesel engines. Available to subscribers now in the Member's Area.
Tow testing the new emissions LMM Duramax and 6.4L Power Stroke
A recent pickup truck ad said: "Truck guys will tell you taking off with 10,000-lbs ain't no picnic. Stopping 10,000-lbs ain't no picnic either." We agree. Towing tests are few and far between in the automotive media. Most of what we see are dyno results, 1/4-mile elapsed times, and generalized reports about on-road capability. Those types of tests can provide some clue about what we might expect while towing a heavy trailer, but they fall short of a real towing evaluation. Part of what most potential GM & Ford buyers really want to know is how the newest diesel pickups stack up against one another in a real-world towing test on a real hill while towing a trailer that weighs at least 10,000-lbs. That's what this test was all about.
GM's new light-duty Duramax
General Motors announces an all-new 4.5-liter V-8 Duramax high-output diesel engine for the Chevrolet Silverado and GMC Sierra light-duty pickup trucks and the HUMMER H2. The engine fuel efficiency offers a 25 percent advantage compared with gasoline engines. Environmental benefits of the new engine include a 13-percent reduction in CO2 versus gasoline engines, and at least a 90-percent reduction in particulates and NOx when compared to diesel vehicles today. GM-Media News Release
Lessons learned about the 6.5L Diesel
Helping owners of these GM vehicles has been our primary focus these past 11+ years, and we've covered a lot of ground during this time. Based on some of the discussion topics appearing in our bulletin board and from reading the email I receive, it appears that some of what we've published about the 6.5L diesel during the early days of The Diesel Page might need to be restated for the benefit of the new 6.5 owners. The 6.5L cooling system upgrades, compression ratios, turbocharger boost pressures and more are what we'll discuss this time. Available now in the Member's Area.
AM General has a new 6.5L diesel engine. The genesis for the engine modifications we'll discuss here began in June 2006 when I first heard about a series of proposed changes to the 6.5 that would allow for a significant power and durability increase. The HMMWV is getting heavier, with all the armor and military technology being added, and a more capable diesel engine became necessary. The power increases, as well as structural and component changes we'll discuss here will take the 6.5 to the next level in performance.
After six years and nine months of continuous production, DMAX Ltd., the maker of the Duramax 6600, celebrated producing its 1,000,000th engine on April 16, 2007. According to DMAX, they can sell all of the engines they produce and more. Go here to see the story and learn more about what has made the Duramax 6600 so successful.
The New Emissions System
The new VIN code 6 2007i LMM Duramax equipped trucks have arrived, and along with them the new DOC/DPF (Diesel Oxidation Converter/Diesel Particulate Filter). Changes in the emissions system are the big news, and this article should help to explain what's new & different and shine a light on what LMM owners need to know to have the fewest problems. Go here to see original photos of the new emissions components, and learn how these components function. Do we need to worry about the 2007 emissions systems? Available now in the Member's Area.
EGT Pyrometer Installation
Why do we need an EGT (Exhaust Gas Temperature) gauge? Well, if you're adding power to your 6.5, excessive exhaust temperatures could toast your engine. Having an EGT gauge helps you to protect the engine. This article will show you where and how to properly install the pyrometer used by your EGT gauge. Available now in the Member's Area.
for the Early GM Diesel Trucks
The 6.2L diesel equipped trucks and SUV's were all equipped with rear drum brakes. Upgrading to rear discs help in two important areas - reduce unsprung weight and improve stopping ability. Demands on the braking system increase as loads or vehicle speeds increase, and stopping can sometimes be more important than going fast.
Easy upgrade to GM's 2006 Mirrors
I recently upgraded the stock mirrors on my 2005 GMC 2500HD to the 2006 model trailer towing mirrors. Although the stock mirrors extended for trailer towing, I was not happy with the narrow field of view the stock mirrors provided. For the 2006 model year, GM released a new style extendable towing mirror, similar to the Ford SD towing mirrors. Go here for a photo illustrated step by step guide to installation. Available now in the Member's Area.
for the 1982-2000 6.2/6.5 GM Diesel Trucks
A variable timer allows you to power the glow plugs automatically, or for as long as the switch is held in the momentary-ON position. Adjustability is a key feature - longer glow times can be dialed-in during the winter months, and then reduced once warmer temperatures arrive - simple to install and easy to use. Available now in the Member's Area.
Diesel Power for AM General's HMMWV
For nearly 23 years, AM General's High Mobility, Multi-purpose Wheeled Vehicle (HMMWV) has been powered by the Detroit Diesel designed GM 6.2L & 6.5L diesel engines. GM's production capacity, overall low cost and adequate performance made the original GM engines a natural choice for AMG's front-line military rig. Many evolutionary changes were made to this engine family through the years, but perhaps the most significant enhancements have appeared since November 2001. AM General assumed control of engine production in 2000, and immediately began making plans to improve the durability and performance of the 6.5L Turbo Diesel engine - now called the Optimizer 6500.
Identification, Restoration & Repair
Book Review: Drivetrain expert and author Jim Allen has teamed up with a leading drivetrain component supplier, Randy Lyman of Randy's Ring & Pinion, to produce a profusely illustrated and perhaps definitive book on the drive axle and differential.
Diesel power is becoming cool! Wasn't always that way. Eleven years ago, The Diesel Page began as a way to help 6.2/6.5 owners solve problems and improve their ownership satisfaction. This is still a big part of our mission here, but we have also grown to include the newest GM diesel engine - the Duramax 6600. No web site has done more for the GM diesel community than TDP. Find out what's new and where we're going!
Technical Service Bulletins
Here, you'll find 43 of the top GM Technical Service Bulletins pertaining to these trucks and the Duramax/Allison drivetrain. Included are the bulletin number, the title and an in-house written summary for all 43 listed bulletins. This compilation contains great information you need to know. Available now in the Member's Area.
No Engine Crank and No Tech II Scan-Tool Communication with TCM
Going all the way back to 2000, GM has admonished technicians and vehicle owners not to allow the metal-cased ECM (Engine Control Module) and TCM (Transmission Control Module) to be used as a grounding location that could subject the electrical system to excessive electrical current. Find out what happens when this occurs. Available now in the Member's Area.
What Year 6.5 is best? What to look for?
I've answered a lot of questions through the years concerning the GM diesel engines. The hardest question goes something like this: "I'm considering buying a 199x Chevy with the 6.5L turbo diesel. I've heard some bad things about this engine, and I don't want to buy into more problems. I want a diesel, but is this a good engine?" That's a tough one. Go here for the answers. Available now in the Member's Area.
4L80-E Shift Calibration
The ubiquitous 4L80-E Throttle Position Switch first appeared as part of the GM diesel powertrain in 1991 with the introduction of the then brand new 4L80-E electronically-controlled 4-speed automatic overdrive transmission. Whether either for gas or diesel application, a TPS relayed throttle position information to the transmission control module (TCM), which allowed the TCM to control shift scheduling and shift quality. At the same time, GM designed a new TPS that bolted onto the passenger side of the DB2 fuel injection pump, making for an easy installation. Go here to learn how to adjust the TPS to allow correct 4L80-E shift calibration. Available now in the Member's Area.
& Vehicle Applications
Designed to meet the 2007 emissions regulations, the 2007 LMM Duramax 6600 diesel engines have met the challenge, and continue to lead in power & torque. More power and torque are the good news. Go here to learn all of the details about the new engine and its application.
Go Big or Go Home!
Trucks at SEMA were there to attract attention - and boy did they! Each of the 2100+ Vendors and manufacturers who attend the annual Specialty Equipment Market Association event needed something special to lure some of the 100,000+ passers-by (and the media) into their booth. Having an eye catching truck helps them do just that, and this year was no exception. Here is a collection of GM, Ford & Dodge (and Toyota) trucks I thought stood out in some way from the others at SEMA 2006. Have a look!
photos & technical details!
What do the 2007 emissions regulations mean for the future of diesel?
Reducing emissions components found in diesel exhaust is not without its share of engineering challenges and increased cost. While some fear for the future of the light-truck diesel market, we here at The Diesel Page remain optimistic - in fact, confident that the current trend in light-truck diesel usage will continue. Go here to find out what we'll need to know and how the new fuel and emissions requirements will affect all of us.
The Face of the Future
GM's 2007 Silverado/Sierra 1500-Series Pickup Trucks
GM has a lot riding on the 2007 model year. With nearly 50% of all new vehicles sold in the U.S. being pickup trucks, this market is something General Motors simply has to do well in. Introduced as a 1999 model, the outgoing Silverado is now eight model years old, and has begun losing ground to the fresh faces offered by both foreign and domestic competitors. Enter the GMT-900, a new for 2007 body style that introduces a long list of refinements in addition to all new sheet metal. Included here are new photos and information about the new 1500 series trucks, and we'll discuss how the design features shown here could appear in the upcoming 2500HD/3500.
Pull-Off VII - July 2006
The Duramax Raises the Bar - Again!
A looming grade can either induce dread or anticipation; depending on whether you're driving the highest rated diesel pickup the "big three" have to offer. Included here is an accounting of the 12 trucks that pulled the hill this year, which included 4- Duramax's, 4- Powerstrokes, 2- Dodge Cummins, and 2- 6.5TD's. Find out what truck is the King of the Hill.
Pull-Off V - July 2004
After considering all the various cold air intakes systems available for my truck, I decided to develop my own, which only cost a few dollars and an hour or so to complete. Keeping the intake air as cool as possible improves power and may improve fuel economy. While inexpensive, this modification retains the excellent filtering ability of the stock air intake system.
the LLY Duramax ECM
Product review: Last month we showed you how to update the 2001-2004 LB7 Duramax ECM with one programmed for more power & better fuel economy. This month, we look at the 2004.5-2005 LLY Duramax ECM.
the LB7 Duramax ECM
More Power - Better Fuel Economy!
Product review: The various electronic power products have done a remarkable job of increasing Duramax diesel performance, but till now, we've had to accept whatever programming or tuning options were offered by the aftermarket. The recent appearance of custom ECM (Engine Control Module) programming has increased the number of options for nearly every truck owner, whether they're looking for a few more miles per gallon, a safe towing program or a killer track tune. Kennedy Diesel is now offering custom ECM tuning, which provides for a host of additional programming features.
Retrofit, Troubleshooting & Repair
Since the late 1980's, GM has used a firewall-mounted electronic cruise control module that remained more or less unchanged through 1999. The 6.2L/6.5L diesels used this cruise control module in the 1988-1993 model-year 6.2/6.5 diesel (mechanical fuel injection) equipped GMT-400 trucks and in the gasoline engine equipped C/K trucks & SUV's through the 1999 model year. Millions of these cruise control modules exist, and knowing how to retrofit a gas module into a diesel application can save you a ton of money if you're having a problem with the one you have now. In addition, these cruise control modules can be used when converting an electronically fuel injected 6.5 to mechanical fuel injection. If you fit into either category, or if you need to troubleshoot your existing cruise control system, this article is for you. Available now in the Member's Area.
Addressing a possible glow plug failure.
In an effort to reduce cold-start induced white smoke, GM has upgraded the glow plugs, the glow plug controller and the ECM programming on a continuing basis since first introducing the first Duramax 6600 in the fall of 2000. The 2006 Duramax, identified as either RPO code LLY (early '06 models) or LBZ (late '06 models), saw another glow system upgrade. Faster-acting glow plugs and shorter cycle times combine to further reduce white smoke after a cold start, while helping to make diesel engine operation more transparent to those more familiar with starting a gas engine. However, there have been a few bumps in the road regarding the 2006 glow system.
Dual Alternator Installation
for the 1996-2000 6.5L TD Equipped Vehicles
In a quest to accessorize our vehicles to our tastes with items such as lights, stereos and so on, we sometimes overlook what gives life to these accessories - the charging system. The original charging system is generally adequate for a factory-equipped vehicle, but increasing the electrical load on your factory alternator could lead to problems. There are two options to alleviate the power shortage: a custom high-output single alternator or dual factory alternators. Dual alternators were optional for the 6.5TD, which makes acquiring the factory brackets and hardware easy to obtain and install. Go here to see how to acquire the parts and make the install. Available now in the Member's Area.
Member Arjan Kolkman reports on one of the most unique 6.2L diesel conversions we've heard about. The amount of ingenuity and fine workmanship make this worthy of inclusion here in The Diesel Page.
2005 Annual Meeting
Now more than 5 years old, the Washington, DC based Diesel Technology Forum was created to highlight the economic importance of, and push for, continued development of clean diesel technology. Find out what we learned while attending the 2005 meeting.
Extending the Glow Cycle for 18:1 Compression Engines
As the weather turned cooler in the late fall of 2005, we learned that our 18:1 low compression engine needed more glow cycle time to produce quick and clean cold starts. This article illustrates a simple and inexpensive modification designed to provide manual control for the electronic 6.5 glow system. Available now in the Member's Area.
New GMT-900 Body-Style
Read about GM's GMT-900 body styling changes. How will this translate to the 2500HD/3500 pickup trucks?
For the Duramax 6600
Fuel Quality can determine whether your diesel fuel injection system provides typical service or whether you are plagued with frequent visits to the dealership. GM recently upgraded the factory fuel filter element in an effort to help protect the Bosch high-pressure common-rail fuel injection system used by the Duramax 6600. Trapping more and smaller particles in the fuel can improve both fuel quality and injection system longevity. Lubrication Specialist Greg Landuyt has developed an easy to install and cost effective auxiliary fuel filter kit that can add a significant safety margin to the diesel fuel you're using.
for the Duramax 6600
As diesel fuel injection systems become more complex and more sensitive to fuel quality, owners have become more tuned-in to the nature of diesel fuel systems. Being able to check fuel pressure (vacuum) can help an owner diagnose a future problem or allow him to monitor the condition of the fuel filter in an on-going basis. This not only can save you a lot of frustration in the high-stakes game of vehicle service, but can save you money on fuel filters by not replacing them till the fuel restriction gauge tells you it's time.
KD Boost Valve for the 2001-2004 LB7 Duramax 6600
There's an old saying that says "offer a great $5 part that installs in 5 minutes, and you'll sell a million of them." Well, the KD boost valve might be a little more than $5, but it is still inexpensive, installs in minutes, and offers a lot of bang for the buck. This simple device increases maximum boost pressure about ~5-8 psi, and makes the factory LB7 turbo a lot more responsive under all operating conditions. Combine this with any one of a variety of Duramax power mods, and you'll see an even bigger improvement in power than what a power mod by itself delivers.
Edge Products host their 2005 all-diesel drag race & dyno event.
The third annual Edge Products' "Weekend on the Edge" event was held near Salt Lake City, Utah this past September. For anyone who loves diesel engines, fast trucks and big-big power, this was a weekend you didn't want to miss. Click the above link to read more about it.
GM's 2006 model-year Pickup Trucks
The 2006 model-year Chevy & GMC diesel pickups began arriving on dealer lots in August of this year. While not much has been added or changed to the pickup styling or option list, the big news is the new RPO code LBZ Duramax 6600 diesel engine. Go here for a look at the new trucks and to learn more about the new uprated Duramax diesel engine.
What you need to know before upsizing tires on your Chevy/GMC 2500HD
Tire size is a proportional feature that plays into how we perceive the appearance of a pickup truck. Most agree the factory tire size for the 2500HD of 245/75R16 has always appeared to be too small. Nearly all agree - except that is, for GM.
Cheap Boost & Fuel Control for the 6.5TD
Back in March of 2000, The Diesel Page published a technical article (2000 Feature Articles volume, page 63) showing how to produce a variable boost pressure controller for the electronically controlled 6.5TD vehicles. This was simply a variable potentiometer that altered the 0-5 volt output of the boost pressure sensor - essentially fooling the computer into "sensing" a lower boost pressure than was actually produced by the turbocharger. This provided a means to increase boost pressure. That same article also discussed altering fuel delivery of the DS4 electronic fuel injection pump by varying the FSD calibration resistor value. Go here to see how easy it is, and learn whether these concepts (original to TDP) help increase power.
Press "YES" for More Power!
Performance tuning/flash programmers appear to be carving out a market with the Duramax performance crowd - and for good reason. Programmers offer a number of unique features that make them a "must have" for any Duramax owner. Here is a brief summary of five Duramax power programmers, and a list of features available for your Duramax.
Product review: Big power can stress unmodified chassis and suspension components in ways that limit overall truck performance. Pushing ¼-mile times into the 13's is relatively easy. Going faster requires more power, more effort and more attention to chassis setup. The recent installation of Kennedy Diesel's traction bar system in our Duramax Diesel hot-rod is a step toward the 11's.
Rebuilding GM's 9-½" Corporate Rear Axle
Product Review: We had to replace original half-ton 10-bolt rear axle in our 1989 Chevy project. The 8-½" diameter ring gear and 1330 U-joint pinion yoke were deemed not up to the task when twisted by a Duramax 6600 producing more than 600-horsepower and 1000 lb-ft of torque. Without going the custom (expensive) route for a stronger replacement, we chose the GM 9-½ 14-bolt semi-floater for this six-lug application. Once acquiring the axle, we visited the experts at Randy's Ring & Pinion for a professional rebuild.
Injector Warranty Extension
General Motors has extended the Duramax 6600 fuel injector warranty coverage for owners of all 2001 through 2004 model-year Chevrolet and GMC Duramax 6600 equipped pickup trucks. Go here to read all about it.
The best just got better!
Text by Jim Bigley
Photos by Gene Wonders
Chevrolet's flagship SUV just got a significant boost in power and capability. Effortless towing and the potential for 20+ miles per gallon make this arguably the best Suburban ever... This Duramax/Allison conversion story is available now in the Member's Area.
For the 6.2L Diesel
By Lee Swanger
Till recently, the two most common tachometer options for 6.2L owners were the Autometer 2888 and Isspro mini-tach. Autometer's tach was introduced for a diesel application, and operates using a sensor on the alternator. The primary drawbacks with this tach were questionable accuracy and a need to calibrate occasionally. Isspro offers improved tachometer accuracy, but required a pair of magnets to be glued onto the harmonic damper for the mag pickup sensor. My goal was to utilize one of the many tachometers made to work with a gas engine's spark ignition. Available now in the Member's Area.
Learn more about the history of 1979 Yamaha XS750SF Special, along with some great photos and technical information that show that vintage Yamaha motorcycles are always in style.
Lots of great stories are scheduled to appear here in The Diesel Page. Become a member of The Diesel Page, and not miss a single one!
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