Updated December 2, 2016
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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.
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.
What do you do when no one will help you?
The answer to that question is "of course, you come to The Diesel Page. We've been helping GM truck owners solve problems since 1996." This editorial first appeared here way back in 1997, but we know it's important enough to run again. Though the GM trucks mentioned here are from a previous generation - not the Duramax, the information remains valid and of tremendous value to those who need it. Knowing what to do could be a real life saver if your truck's warranty has been denied or if a service department simply can't fix your truck. It's human nature to want to begin an internet crusade to punish someone and to enlist other truck owners in that effort. As a first step, that strategy is exactly 100% wrong, if you're interested in solving problems. What appears here was written by one of our members who owned a GM dealership for over 8 years and later served as a state arbitrator, reconciling consumer complaints with the automobile manufacturers. Read this before doing something that will create a barrier between you and those who can help.
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.
LBZ/LMM Fuel-Rail Pressure Troubleshooting
While the 2006/2007 LBZ Duramax powered trucks are generally thought of by many to be the best choice when buying a used GM diesel pickup, diagnostic trouble code P0087 is emerging as the single biggest negative for the LBZ/LMM as time goes by and mileage accumulates. The OBD II explanation for this trouble code indicates that the "Fuel-Rail System Pressure is Too Low", meaning the fuel rail pressure is below what the programming expects. As the 2006-2010 LBZ and LMM Duramax engines accumulate mileage and as the fuel injection system wears, more owners of these trucks are experiencing this problem during some rather extreme and sometimes not so extreme conditions. Let's look at what is causing this problem and discuss how best to deal with it.
The 2013s are here! Go here for all of the new truck details.
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.
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.
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.
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.
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...
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
2011 Chevrolet 2500HD/3500 Trucks
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.
2011 LML Duramax 6600
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 Future of the Duramax
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.
Duramax Head Gasket Failure
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.
Duramax Powered Massey Ferguson Tractor
Here is a story about a Duramax Diesel powered Massey Ferguson tractor owned by Lammert ter Heide, who lives in Holland. This is not the first GM diesel to power this particular 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.
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.
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.
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.
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!
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.
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?
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.
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.
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.
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.
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.
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.
Pro-Stock Duramax Diesel
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. Available now in the Member's Area.
Tow testing the new emissions LMM Duramax and 6.4L Powerstroke
A recent pickup truck ad I saw on television 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 to see 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
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 makes 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.
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.
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 a 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.
& Vehicle Applications
Designed to meet the 2007 emissions regulations, the 2007 LLM & 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!
Product Review: The Allison 1000-Series 5/6-speed transmissions are simply the best and most durable automatics to ever have been installed in a pickup truck. When using stock power, it's practically impossible to hurt the transmission or exceed its torque handling capability. As good as the Allison is, however, it's still possible to exceed its torque handling capability when using a power adder. Most Allisons will hang onto at least 75 additional horsepower and 200 lb-ft of torque, but living on the ragged edge can take a toll on long-term durability. This is why installing a performance-built Allison can increase the fun!
photos & technical details!
Automotive Hinge Solutions
Door Hinge Repair
A new 2-piece door hinge design was introduced along with the 1999 Silverado/Sierra body style trucks. Instead of using replaceable pins and bushings used by the earlier truck hinges, these new hinge pin assemblies utilize a swaged-on two-piece design, installed with non-serviceable Teflon lined bushings. Once they wear out (and they surely will), you're looking at big bucks for replacement. Fortunately, Automotive Hinge Solutions offers precision-made and grease-able replacements that could outlast the truck itself.
and GM Diesels
Operating a diesel engine during the cold winter months demands that all diesel fuel and electrical systems operate normally. Diesel mechanics will tell you that their business activity picks up considerably beginning in about October due to the cooler temperatures. The list of precautionary measures and cold weather tips included here should help your diesel operate reliably throughout the winter.
Installing an Electronic Brake Controller
We all spend a lot of time making our trucks run faster and pull stronger. While that aspect of towing is very important, being able to safely bring your truck and trailer to a stop is perhaps even more important. Follow along as we show how to properly install an electronic trailer brake controller.
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.
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.
Getting acquainted with your Duramax Diesel.
Ok, you just bought a new (or new to you) Duramax diesel truck. You might be wondering what you need to know about diesel engines to get the fuel economy, power and reliability diesel engines are noted for. What you'll find here is essential information specific to the GM diesel engines that could help eliminate some of the problems experienced by new diesel owners, and help you get more out of your "new" diesel engine.
Illustrated Guide to Changing the Fuel Filter
This is simply the best Duramax fuel filter replacement information available anywhere. Great photo-illustrated step-by-step procedure that'll help you be successful the first and every time you need to change your fuel filter.
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 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.
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.
Part of the mystery in servicing automotive air conditioning systems for most people is a lack of understanding in the technology. While it does require specialized equipment and training to know all that is knowable, acquiring a basic understanding of what the various system components do and learning how they work together to produce cool air inside your vehicle will help in maintaining your A/C system - whether you do the work yourself or choose to hire the professionals. Go here to learn how to evaluate and recharge R-134a GM A/C systems.
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 2500HD/3500 pickups began arriving on dealer lots in August of 2005. While not much has been added or changed to the 2005 model 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.
How to make really big power!
Making big power these days requires help to burn all of the fuel provided by the power modules and programs used in competition, and nitrous helps burn that fuel and make more power. If you're after the most Duramax diesel performance, all roads lead to nitrous oxide.
Gauge & Gauge Accessories
The number of different gauges and gauge accessories has grown considerably since our 2002 gauge install piece. I recently stopped by to see the folks at USDieselParts.com, and got acquainted with what's new for those looking for gauges and gauge accessories. Let's have a look.
What you need to know before upsizing tires on your Chevy/GMC 2500HD
An important ingredient in truck appearance is one of proportions. Design engineers consider cab height, cab length, box length, fender well openings and many other appearance details for proper proportions. Tire size is another proportional feature that plays into how we perceive the appearance of a pickup truck. Most agree the factory tire size of 245/75R16 has always appeared to be too small. Nearly all agree - except that is, for GM.
Selectable 4WD Problem
& Easy Fix
A bright yellow Service Engine Soon or Message Center warning usually means trouble. Luckily, this "Service 4WD" Message Center warning light often means you'll just need to replace the pushbutton switch panel that controls the NV-263 selectable-shift transfer case (RPO code NP1). Go here to find out how.
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.
Boost & EGT Gauge Product Review & Installation
For the 2001 & 2005 GM Trucks
Aside from making your new Duramax diesel truck look cool, boost pressure and EGT (exhaust gas temperature) gauges are important tools that help you manage the powertrain and help protect your diesel engine when increasing power. Follow along as we explain how important these gauges are, and show you how to install them.
New GM Pickup Truck Specs & Detailed Information
We're always looking forward to the mid-year announcements of the upcoming model lineup for GM's 2500HD/3500 pickup trucks. Evolutionary changes to both the exterior appearance and to mechanical/electrical systems enhance function and help improve ownership satisfaction, and the 2005 models continue that tradition. While we tend to focus on the 2500HD/3500 models, you'll find the powertrain specs for the gas engine equipped trucks here as well as those powered by the Duramax diesel.
Making the Duramax Rock - Part I
By Jim Bigley
Product Review: You hold in your hands one of the most remarkable power upgrades available... So begins Edge's product description on the back of the box. After having spent some time with the new Juice/Attitude, I tend to agree. In addition to the 5-level 0-150 horsepower increase (depending on model) available at just the touch of a button, the Edge Juice with Attitude monitor combine to produce a truly comprehensive engine performance package for the Duramax diesel.
Performance Air Intake Systems by AFE
for the Duramax Diesel
By Jim Bigley
Product Review: Squeezing the last bit of performance out of a turbo diesel involves improving exhaust flow and intake airflow. Performance air intake systems are the best way to help your engine breathe, and AFE produces a line of products to help achieve maximum intake air flow. Documenting performance improvements using a chassis dyno helps answer many questions, and we thought you might be interested to learn what we discovered after installing an AFE Stage II performance air intake system on our 2001 GMC 2500HD equipped with the Duramax/Allison.
Technology changes for 2004
Introduced in January of 2004, the RPO code LLY Duramax 6600 incorporates a number of significant technology changes. Two forces control diesel engine evolution for all engine manufacturers - Emissions compliance and market share. The technology changes introduced with the LLY address both of these forces. Creating an engine with more power and lower emissions has become more challenging, but that's exactly what the LLY delivers.
Troubleshooting, Removal & Replacement
The Neutral Start Back-Up switch (NSBU) relays angular position of the transmission shift selector shaft to the vehicle Transmission Control Module. The NSBU has caused a problem for some of the early Allison equipped pickups, which eventually resulted in the release of a new & improved NSBU. This short treatise should help you effectively troubleshoot an NSBU related problem, and quickly and inexpensively return the vehicle to service.
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 exterior of the truck was finally completed on the evening of May 13th. That week was rather hectic as we pushed to make the truck ready for a local auto show held in Missoula, Montana on the 15th. We were able to attend, and had a great time, even though there were just 38 miles on the drivetrain upon arriving at the show. The photos shown here were taken that morning. Go here to see the completed exterior truck photos.
for the Duramax 6600
Product Review: General Motors' 6.6L Duramax turbocharged diesel engine was introduced in the 2001 model year 2500HD/3500 pickup trucks and chassis cabs. Along with the new engine came the Bosch high-pressure common-rail fuel injection system. Fuel pressures as high as 23,000-psi demand much from the high-pressure pump and solenoid-controlled fuel injectors, and the less than stellar quality and cleanliness of the available diesel fuel here in the US may present some durability and longevity challenges for these components. Supplemental fuel filtration may be required.
Racing Air Filters
With applications for the 6.5L & Duramax 6600
Product Review: Today's performance air filters must excel at two vitally important and yet polar opposite functions. First, they must allow the engine to breathe without unnecessarily restricting airflow. Second, today's performance air filter is also judged by its dirt capturing ability. Truck owners in the know demand an air filter that allows an engine to perform up to its full potential yet stops virtually 100% of all harmful dust and other airborne contaminants. Creating the perfect blend of unrestricted airflow and maximum dirt stopping ability is the goal of today's performance air filter manufacturers.
The best just got better!
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...
Owner details!! New GMC Duramax/ZF 6-Speed added 1/8/2001!
How do you increase public awareness of a newly designed truck and drivetrain, and demonstrate the power and durability of an entirely new diesel engine?....... Putting the show on the road is one way. Exclusive interview with the Power Tour.
Allison 1000 Series
Duramax 6600 Performance
Fuel Delivery System
Photos By Ron Wong, Text By GM
Here are more of Ron Wong's great TX State Fair photos that are used to illustrate a GM description of the new Duramax Bosch fuel injection system.
The New GM Diesel Trucks
First Technical Report
The new GM Duramax 6600 made its official public debut at the Texas State Fair late last month. Find out what we learned from a close-up and detailed examination of GM's new diesel. This report contains many photos, and a technical discussion on the technology used in this brand new state-of-the-art light truck diesel engine.
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