Another Exhaust smoke question
 

So here's yet another question about exhaust smoke. My 1996 850 Turbo smokes every once in a while, usually at a stop light after driving around town at slow speeds and a fair amount of idling time. Sometimes it does it if the car has been idling for a while. The odd thing is that it doesn't always happen, and it clears up quickly. It happened a little at the mechanics, but not alot so they weren't quite sure why?

The car does use a little oil, but not much, the compression is good, and not problems with the coolant. I wondered about valve stems since I have read that they harden over time, and it is an old car, but I thought if that was the problem it would be more consistant.

Any ideas?

Mine was smoking like that a few months back. I did find a vacuum elbow torn which did reduce the smoking, at the PTC valve. All of it cleared up when I switched to 10W-40. I usually switch in the summer due to our heat. I was burning 1 quart ever 1,500 miles, now I only used 1 quart in 4,500 miles.

Is the smoke more white or blue ??

I thinks its a bit blue, I haven't caught it doing it a lot when I could get a good look, though I did feel it smelled a bit oily, but it doesn't always happen which is why I didn't think it would be rings or valve guide. If it was one of those I would expect the smoke to be pretty consistent. I have heard that the pvc system sometimes needs cleaning. Can oil collect in the pvc system, and would that cause intermittent smoking?

Nothing seems to be out of place under the hood, but I'll have a look and see if I can see any cracks in hoses etc.

The PCV system is supposed to seperate oil from vapor and return the oil to the oil pan and send the vapor (blow-by) back into the intake to be burned.

There is a passage in the PCV black box that the oil drains into another passage cast into the oil pan. This passage can get blocked and there is a chance the PCV fills with oil and that oil gets sucked into the engine.

Do you need to add oil between changes and if so how much, how often ??

Do you need to add any coolant and if so how often ??

My coolant level has been fine, I haven't had to top it up. I usually need to add about a litre of oil every couple of months. My commute is very short, so during the week the car runs to work, then to get the kids at school, so about 10 or 15 miles, and on the weekend we use it for family trips. From what I can tell my oil usage isn't too bad given the age of the car.

i know this is an older thread, but my car is having similar problems and like in the video smoking... usually when i come off "boost" it smokes bluish and when at idle as well and only when the car has been running for 30+ minutes in the city or longer on the highway when the car is cooled down it doesnt smoke
any advice?

If it was valve guide seals leaking it would make sense that when you come off boost and go to vacuum it's sucking in oil around the valve stem.

Have you tried the advise above?

I've been really busy at work, so I haven't had a chance to do anything to the car. My coolant level and oil level have stayed ok, it does smell a bit odd when I turn the heater on, but as I said no oil in water or water in oil. I am due for an oil change, I've been running 10w-30, was thinking of stepping up to a heavier oil and seeing if it helps out with the smoking problem.

i did try something on the way home, i pulled the dipstick out while driving and the car stopped smoking when i put it back in after a few minutes it started smoking again o.O

Update
 

I thught I would post an update. I swapped from 10/30 to 10/40 at my last oil change and it has helped alot. The smoke seems to be gone, even after idling for a while there is barely any at all.

Templar

Well it's not really a "cure" but if it gets the job done.:D Might just be an engine that's getting older and the clearances are a little on the loose end.

That's what I figured. The odo is stuck on 94000 miles, but I don't really know what it is. The motor pulls hard, and other than the occasional smoke cloud I have no complaints.

rspi,

I haven't done the odo repair, I use the trip odo on the computer to keep track of mileage for maintence. I am looking at a 1997 turbo sedan as a parts car, if I get that I plan on swapping the gauge cluster from the sedan into my wagon. Its a metric cluster and mine is a us cluster, but given that Canada is metric it would be a bit easier to have the metric one. Plus the front seats in the sedan are in better shape than mine, and I figured I'd try my hand at rebuilding the motor in the sedan and eventually swap it into my wagon.

I am at the point where I really like my wagon, and rather than spend a couple thousand on another wagon and have to fix it's issues I figure I'll fix the one I have:D