# 2008-2009 duramax



## RLwhaler (Sep 10, 2005)

I currently own 2005 duramax...But, i'am itchin' for the new body style on the 08-09.
Came across an old friend of mine who owns a wrecker service/body shop who just purchase a gmc truck to tow with.He wasn't happy with the new truck due to computer problems.Had to take it back to the dealership twice.the problem is that in his line of bussiness,they would leave the truck on all night and park until' there's a tow.With the new trucks,if you keep the truck on..then you've gotta be driving it,or the computer will somehow malfunction.
Anyone out there with this problem?

RL


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## 41082 (Dec 19, 2008)

Yep same with the new 6.7 cummins. It's from all the new emissions regulators on the trucks. No Idling for extended periods of time.


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## RLwhaler (Sep 10, 2005)

Really? so,he wasn't B.S.iting then.That would beat the purpose of having a diesel then.On occations i would leave the engine on and catch some ZZZZ before or after fishing.Man that really bites.



Mgray said:


> Yep same with the new 6.7 cummins. It's from all the new emissions regulators on the trucks. No Idling for extended periods of time.


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## StarlinMarlin (Aug 3, 2004)

All of the diesel pickups built after January 1st, 2007 must have a diesel particulate filter (dpf). This is part of the stricter epa regulations on diesel engines. This being said, the dpf, similar to a catylatic converter on a gas engine, must reach a high temperature to burn out all of the soot, etc that builds up in the filter. This only happens when a sensonor reads that the filter is full and it will run a burn cylcle.. To reach the temperature required for the dpf to run a burn cycle, the engine on the Duramax must run at a certain RPM for the entire burn cycle. The first models released could not idle for extended periods as the dpf could not do a burn cycle. This however has been addressed with the computer programmed to automatically rev up to the required rpm while idling. This can be updated on all of the trucks by simpily taking the truck to the dealer and having them upgrade the computer progam. I took mine in and they upgraded at no charge.


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## RLwhaler (Sep 10, 2005)

Thank you Sir! for clearing that up.May i ask what year do you have?And how do you like it? Is this your first Duramax?

Richard



StarlinMarlin said:


> All of the diesel pickups built after January 1st, 2007 must have a diesel particulate filter (dpf). This is part of the stricter epa regulations on diesel engines. This being said, the dpf, similar to a catylatic converter on a gas engine, must reach a high temperature to burn out all of the soot, etc that builds up in the filter. This only happens when a sensonor reads that the filter is full and it will run a burn cylcle.. To reach the temperature required for the dpf to run a burn cycle, the engine on the Duramax must run at a certain RPM for the entire burn cycle. The first models released could not idle for extended periods as the dpf could not do a burn cycle. This however has been addressed with the computer programmed to automatically rev up to the required rpm while idling. This can be updated on all of the trucks by simpily taking the truck to the dealer and having them upgrade the computer progam. I took mine in and they upgraded at no charge.


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## catchysumfishy (Jul 19, 2008)

Good Luck! The Duramax has take a down turn just like the Cummins, actually as crappy as the Powerstrokes are now they are more dependable than the other two! Wrecker drivers are dropping them like hot cakes !


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## StarlinMarlin (Aug 3, 2004)

RLwhaler said:


> Thank you Sir! for clearing that up.May i ask what year do you have?And how do you like it? Is this your first Duramax?
> 
> Richard


I have the late model '07 3500 LT3 4x4 dually. Same as the '08 and '09. I previoulsy owned an '02 2500 4x4. I love the new Duramax. It has tons of power. The '06 and '07 classic (early model '07) had an option for the upgraded High Output Duramax. The new style trucks only come with same motor that was previoulsy called the High Output. I pull with mine more than the average person and it handles all I can throw at it. I have regularly pulled loads up to 22,000lb. Previously I had an '02 Duramax and an '06 PowerStroke. Not to make this a ford bashing or anything, but the Duramax will walk circles around the 6.0 PowerStroke. I looked hard at the new PowerStroke but was still not hearing anything real positive about the '08 and newer Fords. Ford's biggest mistake was not staying with the old 7.3 motor. The new Duramax not get as good of fuel milage as the older ones such as the '02 I had due to the new emisions. My old '02 model got close to 16mpg average with no load. My '07 model only gets around 14.5mpg average with no load. But GM is not alone with the poor fuel milage as the new Ford and Dodge diesels also suffer from the more stringent EPA regulations.


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## BIG PAPPA (Apr 1, 2008)

*It's Quite Simple*

Duramax's are somewhat Bullet proof these days. I can't tell you how many Clients i have here that tell me they had no intention of buying a Chevy Diesel until they got smoked pulling their 5th wheel and a Duramax Ran right around them pulling the same exact Travel Trailer.
My shop works on these trucks and the Duramax has become the client pleasing Engine in the last few years and are still improving.
FYI: "DO NOT" install a Performance programmer in the new Duramax's if it is still under Warranty. General Motors is requiring us to take a snapshot from your PCM (powertrain computer module) and send it to them for any repairs that would require a re-program. This records the last 5 programs in your system, and if there is any software GM does not recognize, they will not pay us for the repairs. Therefore voiding the warranty.


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## troutslayer (Feb 7, 2006)

Big P...thanks for the info...I was thinking of getting one proir to my warranty running out...someone told me they would fix it anyway.....another 2cool info-savings
I have the late model 07 duramax and could not be happier....but one thing is bothering me.....when I pull up to a redlight...for a second to 30 seconds when I let off the brake to go you can feel the tranny jump back into gear....This may be my lack of maintenance...it has 45k on it and I was going to wait until 50k to get the tranny flushed...should I go ahead and get it done and who should do it?
Not to hyjack the thread.......One thing about the duramax...it will haul some arse and if I drive 60 MPH back and forth to work...I get about 18MPG....same speed on the highway and I get 21MPG.....but I normally dont drive that slow


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## LDBuckslayer (Sep 12, 2005)

I have a 2008 2500HD 4x4 with 27K on it. I have not had any issues with it. Pulls great and gets decent mileage. I traded in a 05 GMC Dramax on this one. I had problems with the 05, it always surged in traffic . 

As far as I know they cannot flush the Allison trans. I change my spin on external filter every 20k. I will drain the pan and refill at 50K.


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## BIG PAPPA (Apr 1, 2008)

*What Buck Slayer said indeed*

You do not need to flush the Allison. Just every 25-30k miles, change the allison spin on filter, drain the pan and refill with dextron 6 fluid. 2007 models and up require the dextron 6 only. dextron 6 mixes fine with the older trans fluids but do not use the older fluids in a vehicle that requires dex6. As far as that downshift or bump in the rear feeling at stops, take that truck to the dealer and describe whats happening. it's either a programming correction or the slip yoke splines need cleaning and re-lubing. simple 1-hour or less correction. both of these repairs will be covered on your truck under 100k miles. you have a Power train warranty for 5 years or a 100k with 0 deductible. Bring it to me. i'll fix it..


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## RLwhaler (Sep 10, 2005)

BIG PAPPA,
Would you kindly pm me your address and number? just to keep for services.Would be happy to support our local 2cool.

RL


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## StarlinMarlin (Aug 3, 2004)

BIG PAPPA said:


> You do not need to flush the Allison. Just every 25-30k miles, change the allison spin on filter, drain the pan and refill with dextron 6 fluid. 2007 models and up require the dextron 6 only. dextron 6 mixes fine with the older trans fluids but do not use the older fluids in a vehicle that requires dex6. As far as that downshift or bump in the rear feeling at stops, take that truck to the dealer and describe whats happening. it's either a programming correction or the slip yoke splines need cleaning and re-lubing. simple 1-hour or less correction. both of these repairs will be covered on your truck under 100k miles. you have a Power train warranty for 5 years or a 100k with 0 deductible. Bring it to me. i'll fix it..


Don't forgett to change the internal filter. The allison has a filter just like the typical chevy tranny. They suggest every other transmission change to change it (50,000 miles) as well as the external spin on filter.


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## troutslayer (Feb 7, 2006)

So what does.....Ill post another thread.....


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## draker3 (Jun 30, 2004)

oh oh! I had mister car wash flush my allison transmission at 50 k. I have a 2007 gmc allison. Did I hurt the transmission doing that? Should I change the spin off ? It's running great no problems.


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## D-beaux (Jan 19, 2009)

I've got an 08 2500HD with the duramax/4wd. Absolutely love it. I traded in a Tundra and couldn't be happier. Will pull the boat as fast as I want to go and gets much better fuel economy than the tundra did. There are some computer updates and I've had them done, but never one problem. I highly recommend. Also, I noticed now that diesel is same as regular, even a little less sometimes. A year ago it was a dollar more a gallon than reg!


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## RLwhaler (Sep 10, 2005)

D-beaux,I'am shoppin' around for good deal at the moment.I've notice that the new models comes with the Z71 4x4 package.Is that what you have?
remmember the price of diesel last year? :headknock



D-beaux said:


> I've got an 08 2500HD with the duramax/4wd. Absolutely love it. I traded in a Tundra and couldn't be happier. Will pull the boat as fast as I want to go and gets much better fuel economy than the tundra did. There are some computer updates and I've had them done, but never one problem. I highly recommend. Also, I noticed now that diesel is same as regular, even a little less sometimes. A year ago it was a dollar more a gallon than reg!


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## KillaHookset (Jan 6, 2005)

troutslayer said:


> Big P...thanks for the info...I was thinking of getting one proir to my warranty running out...someone told me they would fix it anyway.....another 2cool info-savings
> I have the late model 07 duramax and could not be happier....but one thing is bothering me.....when I pull up to a redlight...for a second to 30 seconds when I let off the brake to go you can feel the tranny jump back into gear....This may be my lack of maintenance...it has 45k on it and I was going to wait until 50k to get the tranny flushed...should I go ahead and get it done and who should do it?
> Not to hyjack the thread.......One thing about the duramax...it will haul some arse and if I drive 60 MPH back and forth to work...I get about 18MPG....same speed on the highway and I get 21MPG.....but I normally dont drive that slow


Sounds like the issue your having is the dreaded chevy driveline clunk. if it feels like when you take off that your tailgate just dropped and it does this every time sometimes when you come to a stop but mostly when you take off its due to a lack of grease in your drive shaft splines, either at the tail shaft of the transmission or if you have a 2 piece shaft at marriage point. When its cooler outside like in the 75 degrees or less it will not happen.
Does it on my 03, and the wifes 01 the clean and regrease will work for 20k+ miles before you have to do it again.


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## gordaflatsstalker (Jul 3, 2008)

I've been wanting to get me a new diesel and was looking at the new Chevy's even though I'm a Ford man. Talked to a guy at a gas station the other day and he said the new Duramax was a beast, but he said it didn't get good mpg. Diesel isn't as high as it once was but that could change just as fast as it once did. I might settle on a new boat instead of a new truck.


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## BIG PAPPA (Apr 1, 2008)

*internal filter??*

i'll try and download the trans schedule, but we do not change the internal filter unless we have transmission internal problems. I don't think we have sold an internal trans filter in 5 years..only the external spin off filters.


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## Blue_Wave028 (Jul 23, 2008)

Dang...I guess it is time to do mine. What is the capacity of the pan? I am at 60K so I bet I am due.


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## BIG PAPPA (Apr 1, 2008)

*Transmission pan capacity*

that Transmission pan holds 7.4 quarts. be sure to fill the spin on filter before installing.


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## Tops - a - Lot (Feb 7, 2005)

*2002 Duramax*

I have a 2002 Duramax with 187k miles.

It has been a soild truck thus far.

It was under recall for injectors and I got 120k before they began to fail.

Engine was completely rebuilt and up til now I have no major problems.

However , my check engine light has come on and I've noticed excess black exhaust when accelerating at normal conditions.Also , I am loosing power and getting heavy exhaust outflow while pulling trailer.

I checked the oil and there is no deisel present,ruling out injectors.

Some have suggested problems with the turbo,but the exhaust is present under normal acceleration.

Oxygen sensors perhaps?

Any thoughts?

Brian


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## BIG PAPPA (Apr 1, 2008)

*TO START WITH*

replace the air filter with a gm "Diesel" air filter.

Excessive Smoke (Excessive Black Smoke) 
Inspection
Action
DEFINITION: Black smoke under load, idle or start up hot or cold.
Preliminary Inspection
• Refer to Symptoms - Engine Controls .
• Ensure the customer has an actual problem.
• Compare the scan tool data at idle with the scan tool data list. Refer to Scan Tool Data List .​Fuel System Inspection
• Observe the actual vs. desired fuel rail pressure with a scan tool, with the engine running.
• Inspect the fuel injectors. Refer to Fuel Injector Balance Test with Tech 2 .​Sensor Inspection
• Inspect the engine coolant temperature (ECT) sensor. Use the scan tool in order to compare the ECT with the ambient air temperature on a cold engine. If the coolant temperature reading is more than 5 degrees more or less than the ambient air temperature on a cold engine, inspect for a high resistance in the coolant sensor circuit or the sensor itself. 
• Inspect the glow plug system operation. Refer to Glow Plug System Diagnosis .
• Turn ON the ignition with the engine OFF. Observe the actual fuel rail pressure with a scan tool. The actual fuel rail pressure should be between 1.0-1.8 MPa. If it is not, inspect for high resistance in the fuel rail pressure (FRP) sensor circuits or the FRP sensor. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.​Air Intake System Inspection
• Inspect for a restriction in the air cleaner or the air intake ducts.
• Inspect for a restriction in the turbocharger charge air cooler.
• Inspect for a restriction in the intake manifold.
• Inspect for an air leak in the charge air cooler with a J 46091 Charge Air Cooler Tester.
• Inspect for an air leak in the air ducts between the turbocharger and the intake manifold.​Engine Mechanical Inspection
• Inspect for incorrect basic engine parts such as the cam, the heads, the pistons, etc.​


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## Cru (May 24, 2004)

*Duramax*

My 2008 GMC Duramax/Allison 2500 Crew Cab 4x4 has been great for its first 10,000 miles. Super nice vehicle. Powerful, comfortable, etc. Pulls the travel trailer and offshore boat great. Just yanks them around. The 6 speen Allison is greatness and the manual shift mode lets you engage the engine braking whenever you see a stop coming. No regrets here. I could have bought any pickup I wanted. I drove them all and towed with the Duramax and Powerstoke before I decided.


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## gordaflatsstalker (Jul 3, 2008)

I test drove a new '09 Dodge with the new Cummins and not impressed. I've heard that all the new diesels are having problems.


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## arron (Jul 8, 2009)

I have an 2008 4x4 duramax dully,and I work in the oil filed. I had this problem, you can get a DPF delete pipe and a Quadzilla chip and that my firend will solve that problem,and add some MPG to your truck. that is what i did.


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