Idles rough and smoking

[wmiller715]

I have an 04 Duramax with 64000 miles. about a month ago it started idling rough and I noticed blue smoke coming out of the exhaust.Upon exceleration it seems to smooth out but the alot of black smoke for a few seconds,any ideas

[Duramaster]

Is this an LB& or an LLY?:confused:

[wmiller715]

It is the LLY,and I think I have found the problem.I had the oil changed right around the time this started.I pulled the dip stick and found the oil level about 1 1/2" above the full mark.I am going to drain about a quart out and see what happens.If this cures it I will contact the business that did the oil change and blister that azzz for them.:mad:

[JohnC]

Sounds like injector problems to me. Chances are the extra "oil" is fuel in the crankcase...

[carco]

Yes, start with the over full oil. An LLY engine; probablely not bad injectors filling crankcase with fuel. The LLY does have an injector harness issue that cause blue smoke and engine miss. The harness is too short/tight to an injector or two cause the connectors/wires to fail/lose contact therfor the injector does not fire properly. Easy fix and under warranty of 5/100000. bob.............

[Duramaster]

the only way that I can think of to get oil in the crankcase of the LLY, LBZ, LMM is by way of the fuel pump shaft seal.;)

[wmiller715]

I brought it to the dealer they checked it out and said the fuel filter was plugged,changed the filter 170.00 later,I picked it up drove it 10 blocks.Stopped at red light and sure enough still smokin,but it has got better.I put a can of seafoam in the fuel and ran it through.That was yesterday ran it today and it only smoked once that I saw.
Dealer says I need an injector flush @ a cost of 189.00.Any alternative that you guys would have would be much appreciated.Thanks:confused:

[Duramaster]

injector flush on a DURAMAX?????!! :eek:

[jharden1]

Had similar problem with my '04 lly. New harness and reflash of eng computer fixed it. I was under warranty, 30k miles.

[Duramaster]

When you took the truck the dealership, did they say anything about the "BALANCE RATES" of the injectors? The balance rates should be no more than 0 +/- 4.5 in P/N and 0 +/- 6.5 in gear. And furthermore, have them "RAMP UP" the fuel pressure and observe the fuel injector balance rates in P/N as well as in gear. At no time should the balance rates go out of spec. :cool:

You might also try adding some STANADYNE to the tank for the next few tankfulls and see if that helps.;)

[wmiller715]

Duramax, please explain the comment on the injector flush on the Duramax.Obviously there is something wrong with that.The reason I want to know is I know very little about a diesel engine,and am quite interested in learning more.
Thanks:D

[Duramaster]

Well it'slike this............ I have been working on the DMAX engine since it was released in 2001. I am not aware of any flush procedure that GM recommends. I would recommend Stanadyne at least every oil change though. There may be after market equipment out there that is capable of flushing the injectors????? You would have to be able to run the engine on an "OUTSIDE" fuel source?? Sounds to me like someone is trying to take you for a ride. :(

[DieselMonk]

Duramax, please explain the comment on the injector flush on the Duramax.Obviously there is something wrong with that.The reason I want to know is I know very little about a diesel engine,and am quite interested in learning more.
Thanks:D

You want a permanent fix, not a patch job. Some how diesel is leaking into the engine and they wanna fix that with a flush? :eek: No flush is gonna fix that, you need parts and a good mechanic!

[wmiller715]

Duramaster/Dieselmonk

Advice taken, I made an appt. at another dealership in another city, after talking to the shop manager. He seemed to be fairly intelligent about diesel engines. The truck goes in today, for diagnostics

[Duramaster]

Wher are you located at WMILLER? :)

[wmiller715]

Southeast Louisiana

[Duramaster]

Well, that's too far from my shop! I'm up here in Portland, Oregon. Good luckwith the repair.;)

[wmiller715]

THANKS ANY WAY.
I brought it to the other dealership yesterday,7:30 am sharp,told them I couldn't leave it overnight,they say ok.3:00 pm they just started diagnostics.
4:00 pm I have to roll out for a meeting.They did tell me there was some sort of problem with the # 4 cylinder. I have to bring it back Mon. morning for further diagnostics.
Something in the back of my mind tells me its gonna be the wiring harness issue.
But whatever it is I just want the thing fixed, or its gotta go.But thats brings up another problem, had a goat its was junk and be be dang if I will be seen driving a Ford.;)

[wmiller715]

Finally got the truck to the dealer, They checkled it and decided that the injector on # 4 cyl is bad. My question is can an injector be bad some of the time, what I mean by that is some days it smokes and idles rough at every stop. Other days it doesn't.
Next question is how long does it take to change out an injector:confused:

Thanks

[DieselMonk]

shouldn't take too long if they have one in stock. please report back, once you have that thing on the road running again. :)

[wmiller715]

They won't have it until Monday, and I have to bring it in Tuesday to have it changed.T hey are saying 4-5 hours

[wmiller715]

Brought truck to the dealer yesterday morning, left it there, got a phone call before lunch telling me to pick it up.
New injector on # 4 cylinder, no smoke, idles better.
Thanks for the input from everyone who responded.;)

[DieselMonk]

Glad to hear!