New to me - 2002 GMC Sierra Duramax 6 6L diesel 2500HD 4wd from '02 Chevy 2500 8.1L gas

kelly.marshall70 · May 30, 2020

I just got a 2002 GMC Sierra 2500HD Duramax 6.6 L. 4WD. I have been driving a gasoline 8.1L Silverado of same year and size, but 2wd. I know nothing about diesel trucks and want to be sure to take care of it as best i can. Would appreciate any recommendations regarding starting procedures, driving a diesel vs. gasoline, what to be prepared for come winter, ANY suggestions that you may have to help me take the best care of and get the most out of this replacement truck would be greatly appreciated!

davester · May 30, 2020

Read the operators manual, and the diesel addendum. Get good fuel and regularly change the fuel filter.

jake111 · May 31, 2020

With 4wd, you need to be aware of the "pump rub" issue in the magnesium tail section of the transfer case. It can cause a pinhole in the tail section, very slowly leak out the ATF (in the transfer case), and ruin it. There are various pump rub kits, or if a tail section is ruined there are aluminum replacements.

I don't live in a cold climate, so I'm certainly no expert about winter prep. Bio-diesel is very good for the motor but gels much quicker in cold weather. Avoid it in the winter if you can. You'll have to study up on anti-gel additives (like Diesel Kleen 911, I think), and using Diesel #1.

The glow plugs and controller need to work well in cold weather. Turn key on, wait for glow plug light to go off (should be about 5-10 seconds in cold weather, I think).

I always suggest a lift pump and more/bigger fuel filtering and water separation. I use a Kennedy Diesel lift pump and Donaldson filter on a Nicktane auxiliary filter head. Beware that some setups flow too much and cause problems with the return into the tank, so be sure to read reviews on the so-called "bigger, better pumps".

I assume you know that the LB7's had problems with the injectors. Again, there's lots to read on that, too. Again, I'm lacking experience with the LB7 since I have an LLY with it's own list of potential problems!!

Niners 365 · May 31, 2020

A good suggestion one other owner here stated: Let glow plugs warm for at least 15 to 30 seconds. When you start a deisel, you need to let it warm for at least 5 mins so everything it warms and compresses operates correctly. In the winter depending how cold your temps get, diesels burn at low temperatures this is why they are recommended engines for generators in Alaska. Anti Gel additives in winter are great, usually only have to do it twice. At beginning and towards end of season. After, run a deisel horsepower aditive to help clean and bust performance. One good thing is you have a Deisel that does not require the Def tank and fluid, so you won't have issues with the injectors for this. I had m iij ne go out couple times now, both because injectors were plastic tips and the spray eats them. When it's time to replace glow plugs, it is definitely worth the $$ to have dealer replace them. They tend to lock themselves worse than a spark plug, and if you break one. It is really tedious and difficult to get them out where they place them.