2005 - 2007 GMC / Chev Duramax Diesel

[Masked Bandit]

From my limited research I think the 2005 - 2007 (Classic) GMC Sierra / Chev Silverado are mechanically identical. Same powertrain but just a few variances in interiors. Assuming that is correct, has anyone owned one of these units for daily driving in the city? What are some common problems you've run into? Any overall opinions or advice?

TIA.

[SKR]

2006-2007 (LBZ) is probably better to get because of increased power and a six speed transmission, but the 2005-2006 (LLY) would be fine as well. I think they're pretty much the same, just different tuning on the LBZ and an extra gear.

I have no problem driving mine, but it's not for everyone. I go easy on it when it's cold. People say stop and go traffic or driving them unloaded isn't good for them, but I don't worry about that and neither do most people who have them. I don't know of any specific problems for those years.

[corsvette]

I have an 06. Mechanically the 2006 is a bit different from an 05.

2005's have the LLY duramax. It's an upgrade from the earlier LB7's with external injectors and more power. These engines did have a history of some overheating/headgasket failure. A blown HG in a duramax is a 30+ hour job to fix, be very careful if buying one that has been used extensively for towing heavy, a truck that sees lighter towing almost never have any issues with headgaskets. A good engine...just be careful, repairs can get rid of a $10k bill pretty quick!

2006-2007 Classic (old) style. This has the LBZ engine and a 6 speed allison. Basically the holy grail of duramaxes, this combo was only offered a short time and was before the style change and emission equipment that came with the redesign. Pretty bulletproof, I don't daily drive mine, but it gets 21 MPG highway empty, 15- 17 MPG towing my 34 ft trailer. It tows like a beast, hard to ever go back to a gas anything after towing with this truck. Common problems are basically centered around the ridiculously cheap interiors. Dash clusters, 4wd switches, heated seats, climate controls, and the power extending tow mirrors all are troublesome. The good news is all this is easy to swap out with any GM truck from a wreckers. Also watch for leaky t-cases and worn out front ends. Check for driveline vibrations, Get it up to 120k, if you feel a humming vibration it needs u-joints NOW, before the vibration causes a crack in the transmission housing.

Not much else mechanically goes wrong. The trannys are tough (without 400+ horse chips) and the engines if maintained go forever. The whole injection system have been super reliable as well, only 01-03.5 d-maxes had high failure rate on injectors. Make sure it gets a fuel filter every other oil change.

My Dad in law has a 2007 new body style. His has the LMM duramax. He had about 10,000 kms on it when he deleted the DPF and put a tuner on it, that made a + 3-4 MPG difference and way more power, still gets slightly worse fuel economy than mine though.

It's tough to find a decent 2006 old style, they are hard to find under 200k and nice ones are fetching stupid money. If you get a 2007+ I'd suggest one with the DPF delete. My Dad in law might be selling his (low kms and fully loaded black crew cab) I find the difference in interior and driving between the old style and new might be well worth the extra money.

[se7en]

Whoa. Some good info here.

[Masked Bandit]

Originally posted by corsvette
I have an 06. Mechanically the 2006 is a bit different from an 05.

2005's have the LLY duramax. It's an upgrade from the earlier LB7's with external injectors and more power. These engines did have a history of some overheating/headgasket failure. A blown HG in a duramax is a 30+ hour job to fix, be very careful if buying one that has been used extensively for towing heavy, a truck that sees lighter towing almost never have any issues with headgaskets. A good engine...just be careful, repairs can get rid of a $10k bill pretty quick!

2006-2007 Classic (old) style. This has the LBZ engine and a 6 speed allison. Basically the holy grail of duramaxes, this combo was only offered a short time and was before the style change and emission equipment that came with the redesign. Pretty bulletproof, I don't daily drive mine, but it gets 21 MPG highway empty, 15- 17 MPG towing my 34 ft trailer. It tows like a beast, hard to ever go back to a gas anything after towing with this truck. Common problems are basically centered around the ridiculously cheap interiors. Dash clusters, 4wd switches, heated seats, climate controls, and the power extending tow mirrors all are troublesome. The good news is all this is easy to swap out with any GM truck from a wreckers. Also watch for leaky t-cases and worn out front ends. Check for driveline vibrations, Get it up to 120k, if you feel a humming vibration it needs u-joints NOW, before the vibration causes a crack in the transmission housing.

Not much else mechanically goes wrong. The trannys are tough (without 400+ horse chips) and the engines if maintained go forever. The whole injection system have been super reliable as well, only 01-03.5 d-maxes had high failure rate on injectors. Make sure it gets a fuel filter every other oil change.

My Dad in law has a 2007 new body style. His has the LMM duramax. He had about 10,000 kms on it when he deleted the DPF and put a tuner on it, that made a + 3-4 MPG difference and way more power, still gets slightly worse fuel economy than mine though.

It's tough to find a decent 2006 old style, they are hard to find under 200k and nice ones are fetching stupid money. If you get a 2007+ I'd suggest one with the DPF delete. My Dad in law might be selling his (low kms and fully loaded black crew cab) I find the difference in interior and driving between the old style and new might be well worth the extra money.

Fantastic info corsvette! It's a 2007 Classic that I'm looking at. SLT with 49,xxx KM for $27,000. From what I can figure that's a very good deal. My only hesitation is that this unit will need to be my DD and I've only got a 4 KM commute. Tradition says that short cycling a diesel like that is going to kill it but then I've heard other people say that newer diesels aren't nearly as troublesome under those conditions as the older ones are.

[ExtraSlow]

aside from wondering if you'll hurt the truck with that commute, have you considered if you'll enjoy it under those conditions?
The truck will not reach operating temps on that drive, so in winter, you are either running it for half an hour before you leave, or dealing with an ice-cold cab. maybe a truck an a 4 cylinder beater? Can grab a decent integra for two grand, that's more fun in the city anyway.

I'm a ford guy, so I can't offer much advice on this specific truck.

[never]

The mileage/price on that seems great. For comparison - later last year, I got a 2006 with 165k for $21k. In 2009, I bought a different 2006 with 100k for $21k.

Other issues with the trucks not mentioned above - wheel bearings seen to go quickly and transmission may leak. And keep on the front end (greasing).

For a 4 km commute, why not just walk or ride a bike? Do you need the truck for towing in addition to the commute? I bought the Duramax because my other truck can't handle the load of what I need to tow. Though the other truck is much more comfortable to drive on a regular basis.

[Masked Bandit]

Originally posted by no|uno
The mileage/price on that seems great. For comparison - later last year, I got a 2006 with 165k for $21k. In 2009, I bought a different 2006 with 100k for $21k.

Other issues with the trucks not mentioned above - wheel bearings seen to go quickly and transmission may leak. And keep on the front end (greasing).

For a 4 km commute, why not just walk or ride a bike? Do you need the truck for towing in addition to the commute? I bought the Duramax because my other truck can't handle the load of what I need to tow. Though the other truck is much more comfortable to drive on a regular basis.

Due to morning schedule (kids to schools / getting to work) walking or biking isn't an option. The only reason I'm entertaining the idea of buying a diesel is for pulling our travel trailer. My current truck (2010 Ram 1500) does just fine over most terrain but the mountains put some strain on it. It's not that the truck CAN'T do it but a diesel sure would be nice in those situations.

I never thought about the never warming up angle on my short commute. If I'm going to bother buying a second car just for commuting then I don't think I would spend as much money as $27,000 just on a towing rig.

Stupid real world economics. The more I look at this scenario the less sense it makes.

[Supa Dexta]

The occasional camping trip, run the piss out of the 1500.

[Kavy]

Originally posted by Masked Bandit


The only reason I'm entertaining the idea of buying a diesel is for pulling our travel trailer. My current truck (2010 Ram 1500) does just fine over most terrain but the mountains put some strain on it. It's not that the truck CAN'T do it but a diesel sure would be nice in those situations.


Damn travel trailers.

I went through this same thing, bought a tent trailer then bought an FJ to tow it. Bought a 16' travel trailer FJ wouldn't tow it so bought a Tacoma. Bought 30' trailer then bought a Ram 1500 to tow it. This is where i sit today with both the trailer and truck bought in 2013.

This cycle will never end.
I also was looking at going with a 2500 for the towing capabilities but then i decided 10 camping trips at around 500km each is 5000km a year in towing and that was not a good enough reason to get a diesel.

Now if I had a boat and was going out every single weekend or my camping trips were 1500km trips all the time then a diesel would make sense to me.

[corsvette]

Originally posted by no|uno
The mileage/price on that seems great. For comparison - later last year, I got a 2006 with 165k for $21k. In 2009, I bought a different 2006 with 100k for $21k.

Other issues with the trucks not mentioned above - wheel bearings seen to go quickly and transmission may leak. And keep on the front end (greasing).

For a 4 km commute, why not just walk or ride a bike? Do you need the truck for towing in addition to the commute? I bought the Duramax because my other truck can't handle the load of what I need to tow. Though the other truck is much more comfortable to drive on a regular basis.


The price of 06-07 Duramaxes are holding very steady. Just like the Dodges with 5.9 cummins. A clean 06-07 Duramax with under 200k will still be fetching high teens.

[legendboy]

I own a 05 Duramax with the Allison transmission. We upgraded to a 30' bumper pull trailer and needed more power.

I love mine, it has been a great truck. I put 4" AFE exhaust downpipe back. Also installed an LBZ up pipe which is about 3x the size of the LLY up pipe. Made a big difference.

My truck started to suffer overheating issues while towing up grades. All it needed was in between the rad and intercooler cleaned out. It was almost completely plugged up. After doing that my cooling fan hardly ever even comes on.

I had to get my front end done last year. Truck still feels new when I drive it :thumbsup:

[corsvette]

Originally posted by legendboy
I own a 05 Duramax with the Allison transmission. We upgraded to a 30' bumper pull trailer and needed more power.

I love mine, it has been a great truck. I put 4" AFE exhaust downpipe back. Also installed an LBZ up pipe which is about 3x the size of the LLY up pipe. Made a big difference.

My truck started to suffer overheating issues while towing up grades. All it needed was in between the rad and intercooler cleaned out. It was almost completely plugged up. After doing that my cooling fan hardly ever even comes on.

I had to get my front end done last year. Truck still feels new when I drive it :thumbsup:

Forgot about cleaning that rad out. Mine was packed full of dirt and feathers.....tons of feathers lol. Runs way cooler now!

[never]

Originally posted by corsvette


Forgot about cvleaning that rad out. Mine was packed pull of dirt and feathers.....tons of feathers lol. Runs way cooler now!

Hmmm, I'll have to take a look and see if mine has anything accumulated.