Puffing smoke when decelerating

[DURAMXD]

I'm not having much luck finding anything searching for this, everything comes up as cold starts or injectors.

Ever since the temperature got cold here (let's call it below freezing), I let the truck "warm up" for 10-15 minutes before I leave in the morning. No smoke here.

When I get in, it isn't up to full operating temperature. When I drive it between warm up and full temp, as I come to a stop at a stoplight I can smell oil for a few seconds. Once or twice I have caught it actually put out a visual puff right before I stop when I have a tailwind and it blows it towards the mirror. I can't see it smoking under acceleration, if I just lift off at speed it doesn't puff, it just seems to be right before I stop (say 5 MPH from 45-55 MPH) it blows a puff or at least fills the cab with the smell for a few seconds. I can't correlate it to a downshift or anything though. Doesn't smoke at idle.

Truck has about 225k on it, 5-10k on new injectors, doesn't smoke any other time, balance rates are good, not making oil. Good oil pressure. Doesn't do it at all once the truck is up to full temp.

I am starting to get a little lope from my FPR, it that trips anything for anyone. But it really doesn't seem like a fuel issue. The smoke doesn't smell like fuel either.

The only thing I can think of is maybe valve guides? Anybody have any ideas?

 

[DURAMXD]

Forgot to mention it is blue smoke.

The only things I can think of are turbo, valve guides or piston rings. But, every turbo I've seen with bad seals does it all the time. Piston rings the same.

Anybody? Never heard of anyone having valve guide/seal issues on a Duramax though.

 

[PureHybrid]

If the valve guides/seals are going out they will usually puff smoke on startup. If the engine isnt using oil, it will be very hard to track down. Generally turbo seals will start spewing oil when they get warm. Is there any stumble from the engine while slowing down, or when your problem happends?

 

[DURAMXD]

It hasn't been using any noticeable amount of oil from what I can tell. I've been leaving it in the driveway since it got cold, my morning drive to work doesn't even let it get to operating temp, so I drive my little beater truck.

No stumble that correlates to the smoke. It does slightly chug while coming to a stop every once in a while, but I have attributed that to the FPR that is starting to act up. It doesn't chug each time and still does it when it is warm.

 

[adeso]

Mine burns blue smoke off and on until it warms up, seems to be below 15* but my engine was build lose. Seems to do it less when I have the oil pan heater plugged in, what oil are you running? And im not worried about it

 

[DURAMXD]

Amsoil HDD 5W30.

I wouldn't be worried about if I knew the motor was built in a way I could justify it. But its all stock and on top of that, it puffed enough the other morning I could see clearly see it out of the passenger side mirror, which is a lot in my opinion.

 

[THEREDDEVIL]

Did u do a Pcv reroute? If so pull it apart at the "t" and see if its plugged.

 

[DURAMXD]

Did u do a Pcv reroute? If so pull it apart at the "t" and see if its plugged.

Federal emissions truck, so no PCV or EGR.

 

[RENODMAX]

still has a pcv, just doesnt route it to the intake

 

[DURAMXD]

Yeah, I guess I should have clarified that by saying that the PCV doesn't need a reroute. Thanks.

Still wish I had something to at least start checking. If there is something obvious that I'm missing, someone point it out. I thought about pulling the turbo pips and looking for oil, but I would think it would have to be blowing a lot more smoke or using oil for that to be a feasible option.