Black smoke from Duramax (Long)

[Mac1234]

I was driving my 04 GMC 2500 HD Duramax/Alison for the first time today on the freeway and had an un GM like experience. The truck is an all stock 6600 LLY with 250 miles on it and after driving for about 45 minutes at 65 mph, I notice this thick black smoke coming out of the exhaust pipe. If I keep the accelerator steady, not as noticeable, but still smokes, however, with the slightest excelleration, massive black smoke. I thought maybe there was some carbon buildup so I put the pedal to the floor to blow it out and again massive black smoke and I hear three or four clicking noise in the engine compartment along with a "bucking" sensation. I pull over to the side of the road, check under the hood, restart it, get back on the freeway and the truck runs almost perfect. Very little smoke, and only if I stomp on it. Runs great another 45 miles and the exact sequence happens again. Smoke, runs rough and then after shutting it off and restarting it, it runs fine. I dropped it off at the dealer Sunday night. I'll post back what they have to say. Probably fuel injectors, I think. Anyone have any other ideas?

[Aluminator]

Please send me an email to dlconstruction@cox.net and I will send ya a few stories just like yours!! I have a list of 6 trucks here in socal that have the same problem.

Mine does it if I take it on the freeway when it is started for the first time on the day.

Don't want it to smoke? Let it warm up by driving it around town for a few miles first before getting on the freeway. If you want it to stop smoking pull over and let it idle for 5 mins and I bet it will run fine.

Dennis

Dennis

[JDaugherty]

I had a very similar experience with my GMC 2500 HD D/A. The truck only had 1K on it and same condition as you stated. Lots, hell lots doesn't really describe it, of black smoke coming from the truck and "buck" with pinging sounds coming from the engine. Turn the enigne off and back on and the issue would go away for a while. Took it to the dealer twice. The finally fixed it on the second attempt. They reported the C107 and C108 wiring harnesses had connectors that were not fully seated, locked, in the connector. These wire harnesses are the large connectors to the left of the fuse box in the engine compartment, the ones the performance upgrade boxes connect into. They had to pull on each of the pins to find out which ones were not locked. I have since driven over 1K miles and have not had a reoccurrence. There is a TSB out telling the dealers to check the connectors. It was dated Jan 04, at least that is what the dealer report indicated.

Something to have the dealer check for.

[Mac1234]

Thanks for the info J. The dealer called me today and said the #7 fuel injector was bad and they were going to replace it. I really don't think this is going to fix it. The fact that turning the engine off and then back on to fix it seems to point to and electrical problem. I'll call the dealer in the morning and tell him about this TSB. Thanks again!

[BillyD]

Does anyone have a follow up to this thread.

My 2004 Chev 2500HD Duramax is exhibiting the same intermittent symptoms as reported by MAC1234:

1) Loss of power;
2) Clouds of black smoke; and
3) Noticeable loss of power.

Injector balance test indicates all injectors within tolerance and no DTCs.

In addition to the TSB for the connectors, another relevant TSB may have been issued on April 15, 2005, but I don't have the particulars.

Any guidance would be appreciated.

Bill

[madmatt]

Bill, LLY or LB7? The tsb for the conn concern is #04-06-04-001 and issued on Apr 15 was #pip3400 which addressed LLY knocking and smoke during warm up

[BillyD]

MadMatt:

This is a VIN 2 LLY truck.

BTW, several weeks ago, the truck exhibited these symptoms as I was passing the truck scales on I580 Eastbound in Livermore, CA. I was cruising at 72 MPH. The roadway is flat, but reasonably wash board (i.e. bumpy). I pulled off at the next exit, inspected the truck, and it ran fine when I restarted it.

Last week, I was driving in exactly the same spot at 72 MPH and the darn thing did it again. I pulled off at the next exit, inspected the truck, and it ran fine when I restarted it. This time, however, I passed another Chev 2500HD Duramax that had stopped up on the freeway shoulder. It didn't occur to me until I was too far along, but I should have pulled over to see if he was having the same symptoms. 20/20 hindsight.

The dealer has since updated the PCM calibration, but when I went on a test drive with the technician today, the truck intermittently loss power, knocked and blew mostly black smoke. I say "mostly", because we both noted a bit of gray smoke too.

Thanks.

Bill

[Kennedy]

There have been a few EGR failures which could present symptoms like this.

I'd also recommend a good fuel additive to lubricate the injectors and keep things happy.

I would suggest doing the first fuel filter change at an early mileage also. Say 3-4k.

I met a 2005 here in Loyal that was dropping blue-white smoke (worse than a Chrysler mini van) at a stop sign. My LLY did a very little bit of the smoking thing when new, but worked out of it...

[Jim Brzozowski]

that was dropping blue-white smoke (worse than a Chrysler mini van) at a stop sign.

Man knows his vehicles.

[Kennedy]

Originally posted by SoTxPollock:
that was dropping blue-white smoke (worse than a Chrysler mini van) at a stop sign.

Man knows his vehicles. Pretty safe bet if you see a cloud of blue from a vehicle ahead at leaving a stoplight it's a Caravan...

[BillyD]

The smoke was one thing...the very loud knocking was the most disturbing aspect of this episode.

If a gas motor made this same sound, it would have detonated itself to smithereens...as in holed pistons and broken rods.

I too had noted some issues with the EGR, but the original post in this thread seemed to much more accurately describe the symptoms; hence, the interest in the connector TSB.

Any further guidance would be appreciated.

Thanks.

Bill

[carco]

Chy products w/ Mitsubishi engines are the smokers. The over seas OEM's have plenty of problems to go around.

[BillyD]

The technician spoke with the GM Tech Center. The guy at GM reported other trucks, mainly in California, have been exhibiting similar symptoms.

They claim not to really know why, but poor fuel quality is suspect. "Poor" fuel quality as in from the refinery, not as in contamination. Specifically, they are concerned about the lubricity of low emissions fuel.

They recommended running a tank or so with Stanadyne additive to increase lubricity. We also decided to change the filter (9,400 miles).

I remain skeptical that this will address the issue; especially in light that my 2001 seems to be running fine. I buy most of my fuel diretly from Valley Oil Company which is my CFN marketer and supplier of diesel fuel to all local independent stations and many fleets.

Thanks.

Bill

BTW, perhaps we should start a separate forum about smoking Chrysler mini-vans...?

[BillyD]

I remain very skeptical that inadequate lubricity is the root cause of the symptoms.

I spoke yesterday with Mr. Manuch Nikanjam of Chevron-Texaco who is the chairman of ASTM Diesel Fuel Lubricity task force. ASTM is the standards setting body responsible for US diesel fuel specifications and test methodologies. He indicated that the diesel fuel lubricity standard of 520 microns, as measured by the HFRR test and set forth in the current ASTM D 975 diesel fuel specification, is the same for all types of diesel fuel sold in the US regardless of sulfur content (15, 500 or 5000 PPM). Thus, if inadequate lubricity were the root cause, then this would be a nationwide problem and not isolated to any particular geographic region or the 2004.5 model year Duramax. More over, all OEs and diesel equipment manufacturers (i.e. Bosch) participated in developing and then approving the lubricity standard.

It seems as if the GM Tech Center is grasping for straws.

Bill

[ 05-03-2005, 05:16 PM: Message edited by: BillyD ]