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Discussion Starter #1
I have been running my superchips tuner for about 15k now and love it.

A friend of mine is a mechanic and just went thru a duramax class. He came back and said he would never run a programmer in a duramax, especially ones that defueled. They had tore down some that were run stock and some that were chipped. The engine that was chipped had 20K on it and the internal parts were pretty much shot. The tops of the pistons were visually terrible, which was "caused" by defueling process. He stated that the dealer may not be able to tell from the cab that you have been using a chip, but once they tare down your engine, it will be obvious.

I have done some searches on the forum and haven't seen this discussion yet.

Please let me know if anyone has any documented facts to any of these issues I have heard about.
 

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um all duramaxes defuel stock unless you put a chip in and turn defuel mode off sounds like he dont know what hes talkn bout
 

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it HAS to defuel some, or the tranny would be toast

did he have any explaination as to WHY?
 

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I think he is trying to scare you!:eek:
 

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Was this "class" taught by GM?
 

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I have had a tech tell me, "to be careful,as gm has done test and programmers/chips,run the motor lean" What??????? UHHHH they all blow black smoke ie...running rich.Dont beleive anything that "GM" has tested.
 

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03LB-7dmax;1584679; said:
I have had a tech tell me, "to be careful,as gm has done test and programmers/chips,run the motor lean" What??????? UHHHH they all blow black smoke ie...running rich.Dont beleive anything that "GM" has tested.
Ask him what a diesel running at stoich is like.
 

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Kevdude59;1584480; said:
The tops of the pistons were visually terrible, which was "caused" by defueling process. He stated that the dealer may not be able to tell from the cab that you have been using a chip, but once they tare down your engine, it will be obvious.
Depending on the particular tuner, fuel pressure may be modified, fuel injection timing and duration for the pilot and main injection events may be modified, boost charactoristics may be modified, defuel charactoristics may be modified, etc.

Yes, evidence of use of a tuner sometimes may be found upon engine teardown; ie, burn patterns on piston tops and wear patterns on cylinder walls. These conditions are dependent on several variables; ie, driving style, mileage, the particular tuner, other modifications, etc. Everything else the same, conditions associated with use of a +50 rwhp tow tune (if any) will be different than those associated with use of +250 rwhp race tune.

Improper defueling charactoristics may contribute to damage to piston tops; ie: if the tuner does not sufficiently defuel due to excessive EGTs.

Provided you use a tuner from a reputable source responsably and in moderation, I wouldn't be concerned about it.

:)
 

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As was already stated, a stock DMax defuels on every shift. Also, if you think about it, you are defuelling the engine every time you lift your foot off the accelerator, so I really don't think that there is any validity to that statement.
 

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Discussion Starter #11
Thanks so far for all the quick responses.

I only had a couple of seconds on the phone with him and what I typed is what I heard. I will try to get ahold of him soon to confirm some details of his experience.

Everyone please continue to respond!

Thanks!
:)
 

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ziadmax;1584730; said:
Ask him what a diesel running at stoich is like.
:exactly:
 

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Are you sure he is a diesel mechanic, or did he stay at a Holiday Inn Express last night.:D
 

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FWIW I know more about these motors than most of the morons at the dealerships that are supposedly trained duramax diesel techs. And I dont know squat.
 

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kevdude if u would please let me no the guys name because he wont be reciveing my business if my truck takes a ****
 

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1tonchev;1586918; said:
Are you sure he is a diesel mechanic, or did he stay at a Holiday Inn Express last night.:D
:funnypost
 

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some peeps just dont pay attention in class and most GM instructors dont know whats going on, so heres the story you are talking about

Document ID# 1809903

Subject:Identifying Duramax Diesel LB7/LLY/LBZ Overpower Engine Breakdown or Non-Function Due to Aftermarket Power-Up Devices vs. Non Overpower Engine Non-Function of Pistons, Cylinders, Valvetrain Components #06-06-01-007 - (04/04/2006)


Models:2001-2006 Chevrolet Express,Silverado
2003-2006 Chevrolet Kodiak
2001-2006 GMC Savana, Sierra
2003-2006 GMC TopKick
with Duramax™ 6.6L V8 Turbo Diesel Engine (VINs 1, 2, D -- RPOs LB7, LLY, LBZ)



<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1809903&psdid=0#ss1-1809903">General Motors Position On Aftermarket Power-Up Devices

Important: General Motors does not support or endorse the use of devices or modifications that, when installed, increase the engine horsepower and torque. Refer to bulletin number 04-06-04-054 -- Warranty Admin. - Non-GM Parts and Accessories (Aftermarket).
Important: For further information on aftermarket power-up kits, refer to February 2006 Emerging Issues Course Number 10206.02D. In Canada, information on aftermarket power-up kits will be covered in the April 2006 TAC TALK program.
Aftermarket power-up devices are non-approved by General Motors. These devices are usually piggy-backed in the main engine harness or remain connected to the diagnostic connector to upload the calibration to the ECM. Recent warranty reviews of returned engines show engine breakdown or non-function due to power-up devices that are utilized for increased horsepower and torque. The following information will assist technicians in identifying overpower engine breakdown or non-function due to aftermarket power-up devices vs. non overpower engine breakdown or non-function.
Non-GM parts can alter the design of the vehicle. GM dealers need to be aware of the quality of parts being installed on vehicles. If failure occurs as a result of installation of sub-par parts, warranty coverage may be denied. Refer to Service Bulletin Number 04-06-04-054 Warranty Admin. --Non-GM Parts and Accessories (Aftermarket).
Installed Power-Up Kit

Aftermarket power-up kits have become a very popular add on for performance-minded customers. These devices can add horsepower and torque and can add additional stress to the engine. These aftermarket calibrations take the Duramax™ powertrain outside of its design torque and horsepower rating. They do this by altering air/fuel ratios and injector timing, resulting in excessive cylinder pressure and temperature. When these calibrated parameters are altered, it will upset the design balance and can lead to a reduction of engine life expectancy. Generally, in inspection of Duramax™ engine failure due to power-up failures, two or more cylinders will be affected.
Installed Power-Up Kit

• Once installed, the calibration may mask itself with the factory original calibration ID and may remain the same.
• A Tech 2® will not positively enable you to identify the use of a power up device.
• Some companies that offer power-up devices claim increases of 150 or more horsepower and 300 or more lb/ft pounds of torque.
• A vehicle that is used to the power-up device potential 100% of the time will see earlier engine wear and breakdown.
• A vehicle that takes advantage of additional power, but on a less frequent basis, may not see premature engine wear and breakdown until later in the engine's life.
• A vehicle not pushed to its limits of the power-up device often may not encounter premature wear and breakdown until after the engine is out of warranty.​
Duramax™ Powertrain Horsepower / Torque Ratings

The following horsepower and torque increase over the past years required new internal components to accommodate the increase.
• LB7 - 300 hp with 520 ft/lb of torque for model years 2000-2004
• LLY -- 310 hp with 605 ft/lb of torque for model years 2004-2006
• LBZ -- 360 hp with 650 ft/lb of torque for model year 2006​
LBZ Improvements

To reliably achieve an increase in 50 horsepower with 45 ft/lb torque, the Duramax ™ diesel had to be revised in many areas. A few of the revisions on the 2006 LBZ were:
• New pistons with a revised compression ratio.
• Wrist pins that are larger in diameter.
• Connecting rods with added material to increase the I section strength.
• Engine block and machining changes.
• Cylinder heads.​
Duramax™ Life Expectancy

The Duramax™ 6.6L V8 Turbo Diesel Engine is sold with a warranty of 100,000 miles/160,000 kilometers. The Duramax™ has been tested to survive upwards of 200,000 miles/320,000 kilometers. The Duramax™ powertrain is designed for reliability, peak horsepower and torque within its design limits. When a customer installs a power-up device, it drastically reduces the mileage ratings.
Important: Cylinder Wall Spotting (commonly referred to leopard spots) is from the induction hardening process of the top 1/3 of the cylinder wall. This is normal for the Duramax ™ Diesel.
Identifying Overpower Engine Premature Wear and Breakdown

When premature wear and breakdown is encountered due to an aftermarket power-up device, it has some very specific characteristics to the internal engine components. The following list will assist in identifying these characteristics as you tear down the engine.




• Pistons will be cracked in the lip area, or a hole in the pistons.​




• Pistons can also be melted on the lip of the combustion bowl, or the top of the pistons can be melted.​




• Crosshatch will be polished off the cylinder wall in the major thrust face of cylinder below ring belt travel.​




• Piston pin bore will show signs of scoring, the wrist pins will be discolored, and can have oil coking on them. The connecting rod bushing surface will have accelerated wear. The above graphic illustration shows connecting rod bushing.​




• Oil coking on the underside of the piston between the wrist pin bosses.​




• Signs of bearing fretting will also be noticed on the connecting rod and main bearing caps. Refer to the above graphic illustration for fretting of main bearing cap 1 and back side of connection rod bearing 2.​




• Excessive heat in engine compartment caused by overpower device. Refer to above graphic illustration 1.​
<A href="http://service.gm.com/servlets/BlobShtml?ShtmlFile=1809903&psdid=0#ss2-1809903">Non Overpower Engine Premature Wear and Breakdown

The following pictures show results of overheat, overspeed, low/no oil pressure or injector breakdown and how they differ from aftermarket power-up device premature wear and breakdown.
Engine Overheat

Overheat can be caused by a loss of coolant or a general cooling system failure. Some of the indicators of overheat are:




• Melted pistons.
• Head gasket breakdown or non-function.
• Warped cylinder heads.
• Crankshaft and connecting rod discolored.​
Engine Overspeed Causes

If an engine has been run faster that design capability (redline), and has caused damaged as a result, it may be a result of one of the following conditions:
• Leaking or failed turbo oil seals.
• Oil evident in the intake runners and compressor side of the turbo.
• Starting fluid use or alterative fuel added to the engine such as ether.​
Engine Overspeed Results

The following are indicators that an overspeed event took place:




• Valve train damage.
• Pushrods that are bent (4).
• Broken valve bridge buttons after cylinder head removal (2).
Rocker arm tip damage (1).
Dry or rusted cylinders from the use of ether, propane or nitrous oxide.​




• Piston to valve contact.
• Cam gear pin shear.​
Lack of Oil Pressure

Lack of lubrication causes rapid bearing wear or bearing to seize.




Bearing failure. Spun main bearings.
Engine Premature Wear and Breakdown Due to Improper Function of Fuel Injector

A fuel injector may fracture a piston or melt a piston but the damage will be limited to that cylinder only and all other pistons and cylinder walls are OK. In some cases hydraulic lock will occur on the suspected cylinder with an over-fueling fuel injector. Hydraulic lock on the suspected cylinder will cause a bent connecting rod. This can be verified with piston protrusion measurements.
Important: Copy aftermarket power-up kit check list when performing an engine disassembly investigation of overpower engine breakdown or non-function.
Aftermarket Power-Up Kit Check List

  1. <LI type=1>Piston cracked parallel to wrist pin.
    Piston cracked in lip area.
    Hole in piston connecting top of piston to oil cooling channel.​
    <LI type=1>Melted Pistons.
    Lip of combustion bowl melted.
    Top of piston melted / missing.​
    <LI type=1>Cross hatching polished off cylinder wall. Cylinder wall missing crosshatch on major thrust face of cylinder below ring belt travel. <LI type=1>Piston pin bore, Wrist pin, and Rod bushing.
    Scoring in upper piston pin boss/black discoloration/oil coking.
    Wrist Pin Wear.
    Rod bushing surface worn and discolored.​
    <LI type=1>Carbon coking to underside of piston.
    Discoloration of underside of Piston.
    Discoloration and carbon coking buildup on underside of piston between piston pin bosses.​
  2. Accelerated rod / Main Bearing wear.
    Fretting on backside of bearing.
    Bearing surface distressed.​
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.
WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

© Copyright General Motors Corporation. All Rights Reserved.
Document ID# 1809903
 

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this is from that bulletin

"When a customer installs a power-up device, it drastically reduces the mileage ratings."
they must not drive a duramax every day. i had my programmer off since feb 7th until feb11. i filled the tank on friday the 9th, 23 gallons. i just filled again this morning feb 13. i usually get a week on a tank. not 3 days. using the programmer for mileage is worth it.
 

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also i work at a dealer and had a crew cab dump truck, 03 lb7. the guy is a mason and regularly had 5 ton of brick in the truck while towing a 10000# hoe. while running the van aiken box full bore. guess what happened. read 2 post up. you would have thought that they took the pictures from this dudes motor that how close they matched. so i wonder how gm did there testing????
 

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there is a big Chevy dealeship in AZ that sells the edge products at the parts counter. So whats all that about then? All you have to do is take all your goodies out, egt probe and all, and say I never had a programmer, or a chip. What are they gonna do or say, "yes you did!" Tell them to show the device and prove it!
 
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