Thoughts on the Duramax engine

[ocho]

Im considering selling my 08 GMC 2500HD gas truck. Nothing wrong with it and it tows my 300MP very nice. I was just thinking a diesels works harder and I could use the extra torque. Here's my situation. I WILL not buy Ford or Dodge for numerous reasons. So, it leaves me the Duramax. Now, Ive researched this bit, but Id like to hear from the folks here. I don't mind getting an early model 3500HD like a 2002 and up GMC if that year motor is built well. I love that body style and can proly find one with lots of life left yet. My biggest concern is the issues GM/Isuzu has had with this motor thru years. So Id love to hear the opinions on which year Duramax is considered the best and why. Thanks Yall, Ocho

[Festus2]

Ocho -
We have an '05 Duramax and have had no issues with it thus far. I have heard that there were some problems with the '04's and earlier but not sure what those issues were. We've been really pleased with its performance in towing in BC's mountainous terrain.

(I hope you are prepared to hear from the folks who have Dodge and Ford and are very happy with their choice.)

[ocho]

Originally Posted by Festus2

Ocho -
We have an '05 Duramax and have had no issues with it thus far. I have heard that there were some problems with the '04's and earlier but not sure what those issues were. We've been really pleased with its performance in towing in BC's mountainous terrain.

(I hope you are prepared to hear from the folks who have Dodge and Ford and are very happy with their choice.)

I am prepared. However theres no way Id ever buy a Ford or Dodge, so if the comments can stay limited to the Duramax. Thanks tho!!

[Hoojs12840]

It has the most consistent setup.( Duramax/Allison). So parts and service are less and more plentiful. I have 2013 and it is by far the best setup I've towed with. Haven't felt this comfortable towing since I drove a Mack truck with a. 53'ft trailer.

[KanTC]

Ocho,

I don't know what's considered "the best" Duramax, but we have an '06 with the LBZ. Purchased new, & now has 117,000 miles... has been great from Day 1.
No issues, so far [knock on wood ] and wonderful for towing in the mountains.

Terri, the Chevy co-pilot

[Tbristol]

I have owned an 04 duramax. Now own an 09, they both have been trouble free and pull like crazy. I will add the 04 got better MPG's. They made some changes to comply with the government EPA regulations in 06 and it hurt the mileage a bit. They made changes in 2011,that increased horse power and they get way better mileage then my 09. Oh I work at the Plant that builds the crew cab 2500HD on up. 90% of the ones leaving the factory have the duramax. Thanks for being a loyal customer. :-D

Sent from my SPH-L710 using Tapatalk

[rode2nowhere]

I have an 04 which had some injector problems, mine are original and I use upper cylinder lube in every tank, truck has not missed a beat.

[Quad]

01-04.5 LB7 engine code had injector failures earlier than you should normally see. Most of these were remedied with updated injectors from GM and a longer injector warranty coverage. Stock 300hp 525tq

04.5-06 LLY engine code had an overheating issue on some trucks. Not always present, just some had this problem. Again earlier yrs more so then later. Stock 310hp 525tq

06-07 LBZ engine code were very stout. If my memory serves correct this generation had a little different piston design and block oil passages were a little different as well. Nothing major. Still basically same engine. Stock 365hp 590tq

08-10 LMM engine code. First yrs with Diesel exhaust filter. Tend to have poor fuel mileage because of using fuel to burn in exhaust. Stock 395hp 650tq

11-present engine code is LML. Very strong truck, excellent stock power. Only down fall I've seen is some CP4 injection pump have failed early. Don't really remember what the causes were.

All, LB7, LLY, LBZ, LMM can have hard gasket failure due to stock head bolts not providing good clamping pressure to the heads. Especially when playing with power adders. The allison 1000 will only hold about 90 or so HP over stock. And Over all, any yrs tow great and have plenty of power. Duramax/allison combo is proven and continues to prove strength especially when in stock form. I myself have a 05 LLY and still love it.


2005 Silverado 2500HD D/A
2013 Laredo 321BH

[ROLIN JOSEPH]

Nothing but nice things to say about my 07 Classic LBZ / Allison. What a superb TV. Love it! (Knock on wood). The torque is phenomenal (650ft/lbs.).
The Allison 1000 six speed with grade braking wraps it all up.

[bfurry78]

I had an 05 2500HD and it was a great truck. I only traded it because I needed a true 4 door and not an extended cab. This truck was my first diesel and I had nothing but positive experiences. I think in buying a later model diesel one has to do their homework I was fortunate that when I bought that Chevy I knew the guy and how well he took care of it. There are plenty of good used ones out there and I know you will be satisfied with that Duramax.

[Drew Waller]

I've got an 06 Crew Cab I bought new, Duramax/Allison and can't say anything bad. I wish changing the fuel filter was easier. 50000 + and no problems. 8-10 MPG pulling a 332TS loaded!

[SAABDOCTOR]

even though i have a cummins engine. All the people i know and the few duramax engines i have serviced. never heard a bad word about them from the customers.

[Hoojs12840]

Main issue with finding a used diesel pickup is finding one someone hasn't "tuned", or modified. Once you start messing with them it's going to start breaking something, or wearing something out.

I'll never understand why anyone would buy a diesel pickup and try and make it go faster or produce more power, as if towing 24,000lbs from the factory isn't enough.

[canesfan]

I put a tuner on mine once for a few days just to try. Tow tune was 40 extra HP, didn't feel any difference, took it off, gave it back. With the Allsion tranny you can't go much more over 80HP without asking for trouble, at least towing, not sure about empty but I don't care it doesn't need it.

I will probably have a 2004 2500HD for sale in the near future. One owner, 73500 miles, stock except for air bags, body and interior near perfect condition, no rust, tears, dents, etc. I know there's a place on here to post for sale so when I decide what I'm doing you might see it there.

[canesfan]

Originally Posted by SAABDOCTOR

even though i have a cummins engine. All the people i know and the few duramax engines i have serviced. never heard a bad word about them from the customers.

And there you have it, I don't think you're gonna get a much more honest answer. Not to say no one elses answer was honest...you know what I mean.

[SAABDOCTOR]

WOW someone called a mechanic honest THANK YOU so much you just made my week end!!!!!

[ocho]

Thanks all for the good advice. The helps a bunch!!

[GMcKenzie]

Originally Posted by Quad

01-04.5 LB7 engine code had injector failures earlier than you should normally see. Most of these were remedied with updated injectors from GM and a longer injector warranty coverage. Stock 300hp 525tq

Remidied is too strong a word for the 01-04.5 injector issues. Replacement runs $2,500 (if you do it yourself) to $6K for a shop to do it and the life of the replacements (all out there are reman's, nothing new) is a crap shoot. I have an early 01 with under 100K miles and did the injectors a year ago. Next time around I am going to do something different (replace the heads with those from an LLY). These trucks get the best mpg of all the Duramax's. Other than a couple other minor issues, the injectors are the biggest problam Yes the warranty was extended but they are all out of warranty now so it no longer helps.

04.5-06 LLY engine code had an overheating issue on some trucks. Not always present, just some had this problem. Again earlier yrs more so then later. Stock 310hp 525tq

Torque is 605. Otherwise this seems about right.

06-07 LBZ engine code were very stout. If my memory serves correct this generation had a little different piston design and block oil passages were a little different as well. Nothing major. Still basically same engine. Stock 365hp 590tq

Torque is 650 in the pickups. All over the place for other applications. If I was to get another Duramax, this would be my choice. Injector/cooling issues fixed but limited emmissions controls so the mpg is not too bad.

08-10 LMM engine code. First yrs with Diesel exhaust filter. Tend to have poor fuel mileage because of using fuel to burn in exhaust. Stock 395hp 650tq

11-present engine code is LML. Very strong truck, excellent stock power. Only down fall I've seen is some CP4 injection pump have failed early. Don't really remember what the causes were.

All, LB7, LLY, LBZ, LMM can have hard gasket failure due to stock head bolts not providing good clamping pressure to the heads. Especially when playing with power adders. The allison 1000 will only hold about 90 or so HP over stock. And Over all, any yrs tow great and have plenty of power. Duramax/allison combo is proven and continues to prove strength especially when in stock form. I myself have a 05 LLY and still love it.


2005 Silverado 2500HD D/A
2013 Laredo 321BH

As I say, I have a low mileage 2001. Done the injectors once and would make different changes if they go again. I love my truck but only drive it 7 months of the year as I have a short commute and don't do much else in the winter so it doesn't do well.

If looking used, try for a LBZ.

[rnkburg]

Lb7 injector issues are mostly related to poor filtration or not changing the filter enough. There is a conversion that puts a much better cat filter on that does wonders. As far as tuning them its all about mileage , yes I have one that is just for fun, but the duramax is the tow vehicle and tuned specifically for that. It makes a world of difference in mileage and performance while towing . Have over 100k like this and doing well.

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[DiverB]

Originally Posted by ocho

I am prepared. However theres no way Id ever buy a Ford or Dodge, so if the comments can stay limited to the Duramax. Thanks tho!!

I promise to reframe from posting why I prefer my Cummins over the powerchoke or dirtymax.

OCHO, The Durmax is a good engine, very proven with the Allison behind it. I would most definitely invest in a EGT monitor to keep on EGT temps while towing, especially if your pulling a long grade. My friends with the newer (2008+) Durmax's have reported fuel mixed with their oil due to all the new EPA crap on them, so you will need to change oil most likely between 5,000-7000 miles. Enjoy your new truck