Pros & Cons of Servicing/Owning the LB7, and a little history.
The above image is of the LB7 first-gen Duramax 6600 in my 2001 2500HD GMC SLE crew-cab. I bought this truck brand new in December of 2000 from our local GMC dealer with just 17 miles on the odometer. Negotiated out-the-door price at the time was $39k. This was the first and only Duramax on their lot. As of late December 2023, the truck has accumulated 155K miles. I have some experience with the first-gen Duramax.
Pros & Cons of Servicing/Owning the LB7... Let's begin with what I've heard about the:
Cons...
1- Changing injectors can be a bit more complicated on the 2001-2004.5 LB7 when compared to the 2004.5 LLY and newer engines.
2- The stainless-steel injector cups have always been considered a negative to owning or buying the first gen LB7 Duramax 6600 because they may add another potential for complication.
Pros...
1- I saw a Youtube video last year that profiled a pretty nice LB7 Duramax/Allison powered 2004 Chevy 2500HD. The video producer paid $800 for that truck because it needed head gaskets and injectors. In short, the first gen Duramax powered trucks are cheap. That truck might have been worth $10,000 in perfect condition, but they are so-so cheap when there's a problem with the engine. It's a great time to score a great deal on one of these trucks. The things to watch out for are rusty trucks coming from the rust belt of the US.
2- The injectors made for the LB7 are less expensive than those used in newer engines, and prices continue to come down.
Conclusion: Should anyone consider purchasing an LB7 (2001-2004) Duramax 6600?
After having successfully removed and re-installed 16 injector cups, I now know that proper injector cup installation is not difficult. You just have to have the right information to help you remove and then re-install the LB7 injector cups correctly the first time.
Yes, replacing injectors is a bit more complicated on the LB7, primarily because you must first remove the upper valve covers, but with the improvements in LB7 injector technology and design, these engines can go a long-long way between injector service. As a result, replacing all eight injectors will require a bit more time than it might on an 2004.5 model year LLY or newer Duramax. However, working on an LB7 is pretty straightforward. It's not difficult if you have the right information, and doing the work yourself will cut the service bill in half.
Just about anyone who has some mechanic skills can replace the LB7 injectors. The Service Guide linked below walks you through the process step by step. Before I replaced the head gaskets in two LB7's, I tended to agree that the newer engines could be a better choice when looking at a used truck to buy. However, with two head gasket projects now in the rear view mirror, I am convinced the LB7 could offer the best value in trucks 10 years old and older. Servicing the injectors and injector cups should not be a deterrent to buying a first-gen Duramax 6600. The decision concerning whether to buy an early Duramax powered truck should be about overall condition, not just whether it's an LB7.
No fail service for injector and head gasket replacement: https://www.thedieselpage.com/durama...rviceguide.htm
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