P2146 Power Loss and Knocking

[Michelstj]

I own a 2004 sierre 2500 duramax. I bought it in June 2007 with 60,000km on it. It has a reoccuring problem of the engine light going on, loosing all power and knocking. This has happened to me about 5 times so far. The engine will return to running normal sometimes after stoping and restarting the engine once or somtimes restarting the engine many time over many hours. The computer shown a P2146 code. The diesel mechanic at a gm dealer could not find the problem but did let me know about a gm bulletin that says to replace the harness on an injector and check for exposed wires as a result of rubbing against another component. I don't feel that this could be the problem because if there was a short or a break on a wire in the harness why can I drive my truck up to 2500km between occurences?? I'm I wrong??
Can anybody help?
When in "limpmode" (when this problem is occuring) is it safe to drive the truck? It will only go about 20km/h
If the shop will perform the work on the bulletin, should it be covered under warranty?
Thank for any help.

[samdweezel05]

Sometimes a "kocking" sound on a diesel can be misdiagnosed. I have found many times that it is nothing more than an injector that has failed or as you stated, a problem with the harness or wiring to the injectors. If it goes on for too long it will lead to major internal damage like a spun rod bearing. I just took apart a cummins M11 that the owner told me had a bottom end knock. Turned out it had a cracked head and had no compression on one cylinder. I would guess that it is an injector problem but is it the actual injector or a wire, I can't say.

Phil