I have a 2004 GMC Sierra Dually, D-max/Allison, took delivery 11/03, I assume second generation engine. Truck died at 17,000 miles, all injectors replaced in June 04. Yesterday, same symptons started, (hard starting, idle ponying), truck died at end of day/towed to dealer (now 33,000 miles).(Coincidentally, my partners 2003 Chevy Silverado D-max/Allison was towed to the shop 2 days ago, same symptoms, 42,000 miles)

The question is this - Have these jerks finally solved the injector problems, or not? Judging by the internet posts it seems that GM is ripe for a class action suit.

both the LB7 and LLY(new one) motors have injector issues. To be sure, check your VIN# on the I believe 8th digit.. if its a 1 you have the first gen LB7 and if its a 2 then you have the new LLY motor. That will at least give you a point of reference.

a GM diesel mechanic told me that GM is making a new injector to fix all the issues with both engines. whether that is true or not, I can't verify.

good luck
B

You have a first gen LB7.

No LLYs were sold until after Jan 1st 2004.
Your truck was an LB7.

I have yet to have an issue with my injectors. I know that if any water, from bad fuel, ever gets to the injectors, this could damage them. i have always ran an additive in my fuel, Stanadyne. The one time i didn't put an additive, I had received some bad fuel from a BP station. I pulled over and added some in the tank and it cleared up in a matter of minutes. Then went to the nearest store to get a fuel filter and replaced it. I went to the BP station to report the bad fuel, but when i got there, their filters on the pumps were clogged and they already new of it. That proved it was bad fuel. But I never had to replace my injectors on my LLY. I guess I am a lucky one. had mine refleashed recently just to make sure I have all the updates.

Injectors continue to be a problem. I believe injectors problems can be lessened considerably by installing a good 2 micron prefilter and usinfg fuel additives. I have a Nicktane filter and find that it does a good job. After changung filters with 8k on them I found the Cat filter in the Nicktane set up was a little dirty and had a minute 9 few drops) amount of water in the bottom of the can. There was some other residue to, but I don't know what it was. The OEM filter looked almost like new and would hhave easily run another 7-8k or more and probaly still looked just a little used. My own personal feelings are that a 2 micron prefilter is a must have.

They have had some injector problems. I really believe its a small number in comparison to the amount of trucks made. You can read the thread on injector failure survey. If you also do your research you will see on every other vehicle manufactures site there will be injector failures and other problems. I feel the duramax is an excellent motor. Do your homework and you will see also. I would also demand the dealer to consider looking deeper than your injectors for their failure. They may have fixed the end result of a deeper problem.

I would also demand the dealer to consider looking deeper than your injectors for their failure. .Where would you suggest we start looking, Bosch?

I am no mechanic but what I meant was for the dealer to look at other things that could be broke in the injection system that are overworking or causing the failure. Some people stop at the easy fix first. There are allot of people without problems at all. For someone to get this may sets of injectors would tell me to dig deeper. Could be a glitch in the ecm , bad pump, ect. Just speculation.

If both you and your buddy are having injector issues with that few miles I would look at other issues as well. If you are going through a set of injectors every 17000 miles your fuel source might be a problem. Just a thought.

I am a ford mechanic and i have a 04.5 LLY and I have had some issues mainly electrical but we need to know we are lucky when the new 6.0 powerstroke came out i couldnt even start to list what all was going wrong with it and still is going wrong with it At least GM is trying to sort out the problem Ford ended up blaming the problem on other companies and alot of people are still having problems.

I am a ford mechanic and i have a 04.5 LLY and I have had some issues mainly electrical but we need to know we are lucky when the new 6.0 powerstroke came out i couldnt even start to list what all was going wrong with it and still is going wrong with it At least GM is trying to sort out the problem Ford ended up blaming the problem on other companies and alot of people are still having problems.
Now that makes me smile to see a ford mechanic saying that to GM guys.

Thanks for all the info. (Truck still in shop, haven't heard from dealer yet).
As far as the fuel goes - I've been buying all the fuel from Hess,which is an extemely high volume diesel station. Point of reference, I've been using the same fuel in my John Deere Excavator, Dozer, and Ag Tractor for years without a single problem. (Wish JD made a truck engine).

It would be sweet if Deere made a truck engine, but then again the new 8020 series motors are also going with super high pressure common rail injection just like our duramax engines. So it may have problems soon too, you never know.