diesl exhaust

[Deputy1402]

Hay! help, I have a 2001, 2500HD 6.6.,164200 miles, injectors replaces at 68,000 miles. Love my truck. Here what is going on, the diesil exhaust now smells like unburned diesel fuel. my mpg has dramatically gone down hill. What the heck. The 6.6 also seems like it is miss fires on one or more cylinders when at idle. One dealer said that it is getting old and other 6.6 do the same thing, but another dealer said that it is the fuel pump. Me, I think that it is the injectors again. Any ideas?????

[madmatt]

sounds like an injector issue.
.

[Shed]

"getting old"???? Are you kidding me? Stay away from that dealer. I have an 01' with 108k and I do not smell diesel in the exhaust. I'm not positive but I'm doubting the fuel pump. To me it sounds like injectors after reading many posts in this page. The diesel knock, exhaust smelling like diesel, and big drop in MPG's all point to injectors. Some of the more knowledgeable will set you straight. I think they will tell you to have the injector return rates checked at the dealer, check the oil to see if you are "making oil". Any odd smoke coming from the exhaust? Wait for a reply from the guys on here who really know this problem inside and out, they will pretty much diagnose it for you and give you some options.. Good luck, I'm sorry to hear about another possible injector problem. Mine were replaced at 64k and will probably be happy to see 164k like you! Good luck. Shed

[DmaxMaverick]

Almost certainly injectors. Keep an eye on your oil level and oil pressure until it's fixed. Find another dealer(s). Not a chance it's the pump, and certainly not because it's "old".

[Mark Rinker]

Don't run it with a 'fuel knock' - while uncommon, sometimes injector failures can burn holes through piston crowns...

If its knocking or clattering...shut it down. Have it towed.

[Deputy1402]

Thanks guys for the response. Yes, there is a white kind of smoke. Especially after the engine has been running for some time, and while sitting at a stop light. Its almost embarrassing the amount of smoke sometimes. Sounds more and more like the injectors.

What about warranty on the injectors. Seems like when they were replaced the dealer said that there was an additional 100,000 mile warranty on the new injectors. If so, I'm coming up on that real fast. Any thoughts?

[Mark Rinker]

You are a couple years outside warranty coverage - you had 7 years or 200K miles from GM's 'in-service' date. No additional warranty on the set they already provided you, unless you have something in writing to that effect from GM or the dealership that did the service. (GM did send me an extension letter of 100K on the second replacement set for my 2004 C4500 (LB7) - but I'm pretty sure that was a medium duty truck only campaign...if you remember getting a letter to that effect after your first set was replaced, I hope you can find it. Its worth about $4500 to you, right now!)

If its smoking that badly, you need to get it repaired, before damage is done. Bring your big checkbook.

[madmatt]

Where are you located??