Duramax 6.6 2500 Diesel Problem

[Ruth]

We lost power on a trip last summer and the Chevy garage told us it was just the gas cap not being tight enough. Seemed to work but it's happened twice since then even with a new gas cap plus we had a loud knock! Not fun when you are pulling the rig. Took it to our mechanic and he said we needed a fuel injector control module as well as a hydroboost and rear differental pinion seal. Anyway got it back yesterday after 2 weeks and $2200. Drove it last night and the same darn thing about 12 miles into the trip! Frustrating!! Any suggestions. Thanks!!

[SlickWillie]

You might want to join Diesel Place, and see what the guys over there tell you. Sounds to me like the engine is going into the limp mode. I see you have an 04 truck. Two different engines were built in 04, the LB7 early in the year, and the LLY later that year. LB7 engines were notorious for injector problems. Good luck.

[lawrenceb42106]

We had a 2001 Chevy that done the same thing. It goes into what they call a limp mode. The fix was new fuel injectors plus new injector pump. @160,000 started eating injectors. See sig. for cure. Injectors covered for 200,000 miles or 5 years.

[swanny]

I might be wrong but, you should get a code. Is there a code?

[Ruth]

Thanks all! Hopefully problem is fixed for about $3000! There were several problems and the fuel injectors were involved. We are at the mechanic's mercy!

[EagleRunner]

I had the same problem on my 2005 Duramax 6.6 about a year ago. Found the problem to be a short in cabling from the Fuel Injector Control module and the fuel injectors on the right side (Passenger side) of the engine. You can find the cable running up to a metal saddle the cable is tie wrapped to. What happens over time is that metal saddle starts to cut into the insulation of the wires in the cable. The fix is to cut the tie wrap and then wrap electrical tape around the cable where it sat on the saddle.

The saddle is just to the left of the alternator. There is a one in wire bundle that comes from the rear of the engine and then at the saddle it splits into two sections. It is right where the two sections split out that the cable is tied to the saddle.

There are codes that are thrown and mine said it was all the fuel injectors for the right side and the control circuit.

The first time this happened, I was pulling the Montana down from Radium Hot Springs up in British Columbia back to the states. After a while, it cleared up and I was able to finish driving on my way. It did take quite a few engine starts and shutdown cycles to get the error to clear before the problem went away. The second time it surfaced I was driving through Bismark ND, just reached the last exit heading west and it started bucking on me and knocking like mad. Managed to backup to the exit and get to a station where I could let it sit for a while and cycled the engine again a few more times. It then cleared up for me to complete my trip back to Washington.

It was when I got back that I took it to the dealer to have it checked. The tech found the problem right away and showed me what was happening and what the fix was.

So give that a try. If you have problems identifying the saddle, let me know. Not all engines look the same, so yours might be different.

Good Luck!

Tom

[Phil P]

Hi

I have found our Chevrolet dealers to be quite competitive with the aftermarket mechanics and a lot more familiar with the product. I use the dealers for all of our maintenance.

Phil P

[Tom S.]

Duramax diesel injectors are expensive to replace because of their location. The engine actually has a two piece head and the top piece has to be replaced to get to the injectors. That's why if I ever have to have one replaced (knock on wood), I'll have all four on that side done. Once the tear down is done, replacing all four on a side isn't much more time than doing just one.

[Karl]

Our 03 with 140,000 miles was under the 200,000 warranty but over the 7 year limit when it needed injectors. Contact with GMC customer service resulted in GM paying for a portion of the injector replacement even though we were over the 7 years. The total cost to me was $1887. The original estimate from the dealer was $4200.

[Frankgad]

Had exactly the same problem back in 2008 with my 2004 LLY at Yellowstone after a very bumpy ride over rough roads, 60 miles from dealer. Called the closest dealer and they told me exactly the same as Eagle Runner. Unfastened it at the cradle, Stripped the insulation back ,re insulated individual wires, and fixed the problem. Took it to the dealer to make sure no damage done he checked it out for me and all OK not even a code to say it had happened.Still going good Deffinitely worth a try.