I left my truck sit and idle for about an hour. After I left and as im coming to a stop a few hundred feet away, a blue cloud rolls by. then it smoked for about 2 more minutes. anyone have this happen??
Blue, not black smoke.

Yeah i've herd its normal.

Mine will do that if it idles a long time. Not so much blue as white (ish).

That will happen because the CAT is not hot enough to burn the smoke, also the soot and other goodies will get plugged up in the muffler and when you rev it up it will blow that crap out. Happens everytime I let my JD tractor idle while I am doing something, normal for a diesel.

mine did it more with the cat than without it, though. and it only does it once in a while sometimes while just stopped at a light after flooring it.

Mine will also do that if it idles a long time. More towards gray/white smoke.
If I just got on it hard and came to a light it with in a few minutes,it will do it also.

I guess it was grey/whitish smoke. thanks for the input.

I bought my 06 LBZ in October of 05 and I noticed some smoke when I got on the throttle. I called the dealer and spoke to a tech he said it was normal and would go away. thats was about 3,000 mile when I called. to this day it still does it once in awhile not as much as it used to and the truck now has 6,000 miles on it. I thought it was because the engine may not have been warm enough, but I have a remote start and the truck runs for 25 minutes before I get into it every morning, which does reduce the smoke but not by much. Even if the truck has been running for a long time it will still smoke sometimes.

They tell me this will deminish over time and go away, who knows,

Too Be Cont....

my lly express does this exact thing. Makes the vehicle look like crap. After about 2-3 miles, it goes away.

My dealer told me that the smoke is because of the pcv sytem. It has a different type of pcv system.

I have a Ford Lightning. The PCV system on that truck is a joke. The intercooler, which is under the blower, gets coated with oil from PCV.

On the other Duramax site, I theorized that at idle, our trucks could be coating the tube to or from? the aftercooler with oil mist. At high idle, this would mist a bit of oil from PCV system. Once driving and turbo, etc is fully functioning, this oil mist would be forced into engine causing blue smoke for a couple of minutes until it was cleared. I was told over there, that it was build-up in cat. That might be so, except the smoke has slowly been a little less each thousand miles. So.... that could signify that internal engine pressure is naturally greater with rings not fully seated, causing more oil blow-by into PCV system. As rings seat, the blow-by becomes less due to lower internal engine pressure.

If it IS the cat, then it should NOT go away and be a normal occurance in the operation of the truck. If it is the rings, and PCV, then this condition will eventually either go away completely or lessen to a GREAT extent.

I am going to watch and wait.:help2: