smoke during long idle

[syrdon]

Appreciate any input on this issue, concerning my 1996 850 Turbo wagon, with just under 200,000 kilometres.

My wife and I took a short road trip from Vancouver BC to Seattle this weekend, and in each direction we ended up in a line-up at the border crossing for about 30-40 minutes. Both days the tempurature was in the low 70's (Fahrenheit). The car demonstrated the same issue both times. By the time we got to the booth at the border, the car started putting out a fair bit of smoke from the exhaust. Again, this was after sitting in line up for about a half an hour, mainly idling.

The first time, I was worried that the head gasket was blown, as the smoke looked fairly white in color. However, once I pulled away from the booth and got back up to speed, the smoke stopped. I pulled over a few minutes later at the first available spot, and the car seemed to be okay again. I checked the oil, and it looked alright (no milkiness on the dip stick), the car was not overheating, and ran fine for the rest of the trip.

Coming back yesterday, the car was fine again, including during some stop and start traffic getting out of downtown Seattle, but exhibited the same smoking right at the end of the border line up again. I thought I noticed the engine sound a little different right before it started smoking out the exhaust, but can't give too much detail on this, perhaps the idle sped up a bit or the engine started idling rougher?

Whatever the issue is, it seems to only happen during periods of long idle, at least for now. I guess I'm less sure that the smoke is from coolant in the oil (i.e. headgasket problem) because the oil still looks fine, and the car does not seem to be overheating at all. In city driving, the needle of the tempurature gauge is right at the halfway point, and during extended highway driving the needle drops down below the halfway point a bit.

Appreciate input on what may be causing this issue.

[gilhuly]

You, my friend need new valve stem seals. period. Oil is being sucked into the combustion chamber past the seals under vacuum (at idle). The operation will cure this completely. Parts are fairly cheap and this can be done with the head on the car with a Schley tool. There is a good write up on this on Volvospeed.

[syrdon]

Thanks for the reply. Sounds like a much better (cheaper?) situation than I had feared. I was doing a little googling this afternoon, searching the phrase "exhaust smoke after long idle", and I came across a few pages from other car sites that described a similar scenario to what I'm experiencing, and there was some discussion about the possibility of problems with the turbo, or the pcv.