Any issues with a 2005?

[winemaker]

Howdy all. I'm looking at a 2005 GMC 3500 this week. I'm not versed in Duramax engines, but I know I want one. Can anyone tell me what model engine ought to be in an '05 and if there are any typical issues I should look for or be wary of, or use to bargain with.
Thanks folks.
Brett

[Mark Rinker]

If there were one production year of the Duramax diesel to be leery of, it would probably be the 2005. (Bracing for the vegtables to be thrown by all the '05 owners...) READ ON...

That being said, the problems encountered were not encountered by all users, and they are otherwise good trucks. 2005 was a transition year from the venerable LB7 to the much improved, but much emissions laden LBZ, and there were a few problems. Some claim that the design of the charge air intake and problems with early model year variable vane turbocharger programming resulted in a heat soak condition, especially when towing in hot climates and/or high altitudes.

I put 80K flatland towing miles on a 2005 with zero issue and know that it is still going strong with the new owner...but consider that I live in Minnesota, the land of natural intercooling...

If the price is right and he didn't live in the BC mountains towing a 5'er, you'll probably be fine...the CAI from an '06 can be adapted, and you can reflash the ECM with a custom tune. Otherwise, same animal. You might want to grill the previous owner on any towing/overheat history, and check the VIN against the GM repair history to see if any overheats were reported during warranty.

If he waffles, run away. Who wants a truck thats been run hot, even in BC? You guys have some serious altitudes to contend with...BTDT :)

[winemaker]

Thanks for the heads-up Mark. We'll see what the history is on this truck.
Brett

[NutNbutGMC]

Howdy all. I'm looking at a 2005 GMC 3500 this week. I'm not versed in Duramax engines, but I know I want one. Can anyone tell me what model engine ought to be in an '05 and if there are any typical issues I should look for or be wary of, or use to bargain with.
Thanks folks.
Brett2005 = LLY engine.

I will say this; I have had several Duramax powered trucks. My opinion is that they are not what they are cranked up to be.

I still have one and don't play to diss the Duramax but they have limits as a light duty engine / truck as to some of the expectations that I have read about.

I started with the LB7 in 2001 and now have a LBZ in a 2007 Classic. These engines have had inherent problems of one kind or another. So far I I am please with the LBZ...I wouldn't allow someone to pay me $5000 to own another LB7. I am not a wrencher.

The LLY has a stock 310 HP and 610 ft-lbs of torque. The LB7 was at 300 HP and 525 ft-lbs. Thus the comment by the Moderator that the LLY is a spinoff of the LB7. I am not certain if the injector issue in the LLY was ever resolved within said generation of engine. Based on this information and the reading I have done here over the years, I'd pass on the LLY. Just my $0.02. Your mileage may vary.

[Mark Rinker]

I have been very satisified with the LB7s I've owned, and equally satisfied with the two '06 LBZs. Even the '05 LLY worked out fine. I think the Duramax line is the best light duty truck ever made. Period.

Advantage of the '06 is more factory power and not yet encumbered by the DPF system.

My truck at present is a 2006 K3500 single rear wheel I have put on over 40K since last October pulling the snot out of it coast to coast and three or four Florida roundtrips. I don't baby them, do 10K mile synthetic oil changes, fuel filters 15K and other regular maintenance and they never miss a beat. I am spoiled never even think of being stranded by the truck - the water pumps, alternators, etc. all have lasted until >150K and they give lots of notice when they are in need of replacement. Even with my use, the OEM brakes go 60K or better and good replacements last just as long.

Whats not to like? 6.0L Fords eat turbos under the same duty, puking shrapnel down their own intakes. Dodge never made a suspension or interior that will last as long as the Cummins, so wheres the advantage? 300K on a 2002 and it was running/ride was nearly the same as when I bought it with 130K...like a rock.

[winemaker]

Let me see if I get this right: the LLY is exclusive to 2005, or did they run in for a couple years?

The main difference from LLY to LBZ is the cold air intake, or is that just part of it?

Are they intercooled?

Thanks again for the info.
Brett

[Mark Rinker]

Let me see if I get this right: the LLY is exclusive to 2005, or did they run in for a couple years?

The main difference from LLY to LBZ is the cold air intake, or is that just part of it?

Are they intercooled?

Thanks again for the info.
Brett

LLY was introduced late 2004 model year, and all of 2005 model year. A few early 2006 will have 'LLY' VIN code, but are LBZs in every way. LLY VIN code 8th position is a '2'. LB7s are a '1'...LBZs are a 'D', IIRC...
Sorry I can't recite mechanical updates from LLY to LBZ but its covered here in detail on TDP. That is just part of the improvements/changes made for ease of maintenance, performance, and for emissions compliance. Basics of bore/stroke/displacement are unchanged from 2001. Head designs have changed drastically from LB7 (valve covers off and resealed to do injectors) to LLY to LBZ (no valve cover removal necessary for injector replacement). Turbo and turbo control system changed from mechanically wastegated with the LB7 to variable vane (computer controlled) with the LLY and subsequent years. First year LB7s were basically emissions free, other than 'Cali' trucks. Later years progressively add more and more emissions equipment, including catlytic converter, EGR system. 07, 08, 09 LMM models have DPF system as well.
Yes, all model years are turbocharged and intercooled, as well as electronically fuel injected. All throttle systems are fly-by-wire. All transmissions are Allison 1000s - sixth gear was added in 2006, previous were 5 speeds. All rear gear ratios are 3.73s.

[winemaker]

Thanks again Mark. I really appreciate your arming me with the information to make an informed decision on a vehicle that is very much what I want/need yet slightly out of my price range.

The reality is that I'm a proud 6.5 owner, and I made an informed decision to buy knowing the gremlins inherent in the beast. I love my truck, but I've outgrown it, and as you described, the Chevs are like a rock, so Duramax it is.

I haul a lot of weight, but only for a few miles (literally over a bridge and up a hill) so, while I need capacity, I don't need something to haul a 35' 5er across the nation. When I go up country, I usually carry 1000 to 1500 lbs of gear, supplies, etc, but that's only 5 or 6 times a year.

From what you and others have told me, I feel I can buy this truck or one like it with relative peace of mind. Grateful for the education.
Cheers
Brett

[Mark Rinker]

Agreed, based on your stated use. Best of luck. BC is the most beautiful scenery in North America, IMO...just damn cold in the winter. :D