LBZ Smoking

[fgrubbs]

I have an 06 DM/A LBZ with 4500 miles on it now, It has started blowing light blue smoke from the exause at idle after a short drive, The smoke last for 2-3 min then goes away. It seems to be more frequent after a short period of acceleration (stop light to stop light) carried it to the dealer today and there were no present or stored codes pulled from the OBD. They finally saw the smoke also and set an appt for me to come back next week so they can dig deeper to find the problem. Has anyone else had this problem or does anyone have an idea what might be going on? I appreciate any input.

2006 2500HD LBZ
CC/Short bed, 4X4 Summit White
4500 miles
avg 18 MPG mixed driving

[More Power]

Does the blue smoke smell like diesel fuel or motor oil?

Jim

[David Proske]

how heavy is the smoke? Mine does this to. I have also seen a handfull of other LBZ's doing this as well.

[fgrubbs]

Jim, David,

Thanks for the replys, the smoke smells of diesel fuel and is inconsistant on the amount, sometimes it is light and others it is so heavy that you can see it blowing back up by the passenger window. I really am hoping that this is something that they can fix without having to tear into the motor.

Frank

2006 2500HD LBZ
CC/Short bed, 4X4 Summit White
4500 miles
avg 18 MPG mixed driving

[Kennedy]

Some LLY trucks did that as well. I caught my 2005 doing it once. My best suggestion for ANY Duramax (or any diesel for that matter) is to look at additional filtration AND quality fuel additives BEFORE poor fuel quality bites you.

[ccole]

My LBZ with 3000 miles on it does this too. Reminds me on an old carburetored car that "loads up" after too much idleing time.

[More Power]

I don't have a definitive answer, but the new lower compression ratio and possibly below average cetane fuel might be part of the answer.

Try running a commercially available diesel cetane booster (i.e. Standayne), try to duplicate the smoke issue, then report back.. :)

Jim

[fgrubbs]

Thanks for the advice. I will post an update on what happens, I also have an appointment with the dealer on Thursday and will let you know what they say.

[Buck]

A mixed cocktail for your fuel per Kennedy Diesel = Total Power & +8 cetane booster. It has served me well over the past 5 years;)

[Mark Rinker]

My '01 LB7 idles clean in stock form.

With a +40hp tow tune installed, it intermittantly smokes at idle.

Just food for thought. Not sure if this answers why your 360hp LBZ might smoke at idle, but seems reasonable as both are running more aggressive fuel maps.

[cowboywildbill]

Any updates, Just wondering what you have found out.

[fgrubbs]

Update, I added Power Service, Diesel Kleen + Cetane boost 106 miles ago. I have not had any smoke since that time. I was waiting until I ran a full tank before I posted the update. It seems to be working. Can any one tell me why I am having to put an additive in to keep the LBZ from smoking. I have been doing some research and am learning more about the ULSD, but why would the LSD/ULSD cause the truck to smoke like that.

[DmaxMaverick]

Adding a cetane booster will help to burn the fuel more efficiently. You may be getting poor quality fuel, and the PS takes up the slack. I use PS, and notice degraded performance and mileage when I don't.

[BILLYDIESEL]

Fuel Rates Are Probbaly To High Causing Injector To Overfuel.
If Fuel Rate Exeeds +- 4.0mm At Idle And +-6.0 While In Drive
Possible Injector Failure