Puff of Smoke on Start-up

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Pete02LSE

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Today...for the second time...I noticed our LS had a puff of smoke from both sides of the exhaust on start-up. It was after we drove it a short distance then turned it off for about an hour and started it back-up. I do not think that the engine was at operating temperature...so...that could be something to do with it.

I cannot remember the conditions the other time this happened...it may have been the same scenario.

Any thoughts? For years, I've been a GM guy and as everyone knows, it's only a matter of time before the valve seals on a 305 or a 350 wear out and they start doing this. I really hope this isn't the case with the 3.9L...especially since our LS only has 57k on it.

I'm not at all panicked...just wondering the cause. Oh...one other thing...the first time it did it was before I replaced the valve cover seals.

TIA,
-Pete
02 LSE
 
Is it a black smoke or a white smoke that usually comes when the car is cold?
 
Sorry...I should have clarified that...it appeared to be a blue smoke. The reason I say it appeared...it because I saw it out of the rearview mirror.

Maybe I'm on crack...because now that I think about it...it was a really pale blue. Which...could have been thick condensation smoke from having driven it a short distance...turned it off...then restarted a short time later.

Still strange though...I only say this because the volume of smoke was more that I would expect from condensation.

Oh well...I'll just monitor it and see what happens.

Thanks for the reply.

-Pete
02LSE
 
Noticed this one time alittle over a month ago, car sits in the garage and I think I had just started it for the first time that day and glanced out the mirror and noticed like appeared to be blueish smoke. It kind of made me think but I figure it was some type of build like condensation or something and did not really worry much more about it and have not seen it since until today just on my way to work, but I'm not even sure if it was smoke or the way the sun hit the rear window and the tint.
 
blue is usually oil. could be a number of things. valve cover gaskets, pcv valve, etc.
 
Bad fuel injector caused this condition for me. Blueish-whitish smoke with a bad fuel smell when the care was shut off and restarted after sitting a spell.
 
"Puff of Smoke on Start-up"

at first, i thought that you were talking about what I used to do before driving to high school everyday. :D-~

but seriously, your problem sounds expensive $$$$$
 
Is the car a little hard to start after it sits for an hour or two after you drive it? That is a tell-tale sign of a leaking injector.
 
My 03 ls V8 smokes at startup too after sitting over night, but then goes away, doesnt really smell like oil to me.It seems to blow dark grey smoke when I punch it on the hiway. I wonder if it is an injector problem.
 
Could it be condensation burning off? Mine have always "smoked" in cold weather. Always until the moisture in the exhaust system burns off.
 
I have had it happen 2-3 times, it seems to be caused by a tired intake valve seal. If i start the car and move it around the driveway and shut it off (running less than 5 min) when i restart the car i might see oil smoke. Once it did knock & miss on one cylinder, then i saw the small puff.

It only happens when the engine/oil is cold- the oil is pumped topside and some makes it down the stem. I don't notice any measurable consumption in 3k miles, i have 118k on my 03 v8. That's my observation so far....Its not enough of a problem to pull the valve covers yet..
 
hotrod03lincolnlsV8 said:
I have had it happen 2-3 times, it seems to be caused by a tired intake valve seal. If i start the car and move it around the driveway and shut it off (running less than 5 min) when i restart the car i might see oil smoke. Once it did knock & miss on one cylinder, then i saw the small puff.

It only happens when the engine/oil is cold- the oil is pumped topside and some makes it down the stem. I don't notice any measurable consumption in 3k miles, i have 118k on my 03 v8. That's my observation so far....Its not enough of a problem to pull the valve covers yet..
Click to expand...

Are you sure that it's oil smoke in that specific circumstance?

On cold start, the fuel injection is very enriched. If you shutdown in less than several minutes, there will still be some excess fuel in the cylinders the next time you restart. This can cause a little smoke from the mixture being too rich, and it can cause rough idle for a few seconds.

If it really is oil smoke, in addition to the possibility of a bad valve stem seal, is the possibility that it is oil sucked in by the PCV system. I've noticed that high mileage 3.9s often seem to have a lot of oil sitting in the bottom of the intake manifold. (It could be true for low mileage ones too, I've never had cause to remove the throttle body or manifold on a lower mileage one.)
 
I didn't the 3.9s had a pcv valve. If so where is it located?
Thanks
 
hotrod03lincolnlsV8 said:
I have had it happen 2-3 times, it seems to be caused by a tired intake valve seal. If i start the car and move it around the driveway and shut it off (running less than 5 min) when i restart the car i might see oil smoke. Once it did knock & miss on one cylinder, then i saw the small puff.

It only happens when the engine/oil is cold- the oil is pumped topside and some makes it down the stem. I don't notice any measurable consumption in 3k miles, i have 118k on my 03 v8. That's my observation so far....Its not enough of a problem to pull the valve covers yet..
Click to expand...

Same has happened to me once or twice a year, always after a short drive.
 
Pete02LSE said:
Today...for the second time...I noticed our LS had a puff of smoke from both sides of the exhaust on start-up.
Click to expand...

this has been happening to my 2002 LS since I bought it. Almost 7 years later, It passes emissions with flying colours, and never gave me any engine troubles (except coil packs and sparks). Mine is a very "Dark" coloured smoke. Its prolly Just carbon build up making its way out.
 
waggs said:
I didn't the 3.9s had a pcv valve. If so where is it located?
Thanks
Click to expand...

The 3.9s have a PCV (Positive Crankcase Ventilation) system, but they do not have a PCV valve.
 
Anyone ever run 5-30 in their LS? I was thinking of going a heavier but don't to mess anything up I have a problem with either a bad valve seal or rings?
Thanks
 
waggs said:
Anyone ever run 5-30 in their LS? I was thinking of going a heavier but don't to mess anything up I have a problem with either a bad valve seal or rings?
Thanks
Click to expand...

5W-30 probably won't cause any harm, but it will add stress to the variable cam timing as it will slightly raise the pressure. It won't help at all with your oil consumption (rings or seals).
 
Ok thanks, That's why I thought I would ask. I love this site, I love my car, not much of a mechanic since everything went computer. you guys are the greatest! I hope to get to one of the meets and meet everyone.
 
This just started happening to me. The first time I noticed it, it was windy so I had just thought the wind had picked up and blew some dust around. But the second time it happened, I had just taken my friend for a ride and had got on it a short distance to show him what the ls is about. Then we pulled in the drive way and I shut it off. Then about 4hrs later I went to leave and I got a puff of a grayish in color could have been white. I tried to smell it and it had no smell. Smelt normal. but since this happened it reminded me about the first time it happened, I had gotten on the car on a straight away and then pulled the car over short distance again (at destination) and a few hrs. later start up puff of smoke.

Thoughts?
 
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