car smokes at idle but stops when driving then starts after 5 min

well, we (they) need make model, year.... is it turbo? etc etc etc

"dzman" wrote

From the tailpipe? From under the hood? From the stereo? From under the seat where you dropped the cigarette?

Is the smoke visible only when you first start the car? What color is the smoke...white, bluish or black.

Valve stem seals. High inlet manifold vacuum at idle which decreases as soon as you open the throttle to pull away,then, 5 minutes later when you are at cruising speed, the manifold vacuum increases as you back off the throttle.

1987 mercedes benz 500sel, v-8 330cid, it seems that while sitting at idle for 5 min it slowly begins to smoke the much more then i run it up to about 2 grand for about a minute or until the fan starts and it seems to slow down on the smoke (its blue) anyway im quite sure its the valve stem seals probably floating since the car has been sitting in a garage for about 4 years.

yes from the tailpipe only.. i see oil underneath the car and near the rear valve cover on the passenger side but its not a bad drip. the engine dosent read hot on the gauge but it sure seems hot under there when i shut r down

it dosent smoke for about 5 min at idle then the smoke comes from the tailpipe slowly then it i rev it up to 2 grand for about a minute (the fan comes on) then it slows down considerably.

so whats next? replacing the valve stem seals and when i go to do that what else should i replace while im there in your opinion, and with a limited income.

Check the valve guide play, (clearance between the valve stem and guide.) If you have too much wear the seals will be temporary fix. Bad oil rings will add to the affect. If you decide to pull the head, have a competent machine shop vet it. (Flatness, good guides, good seals, good valves and seats, no cracks.) That costs relatively little compared to doing the job twice. Make sure they bake it and straighten it.

wws