White Smoke Coming from Engine

We bought a 1998 Mercury Sable with 93,000 for our daughter’s boyfriend. We recently replaced the transmission and alternator before he went off to college. Within one week he noticed white smoke coming from the side of the engine that smelled like something burning. No indicator lights came on and all liquids looked fine. Car also runs well. Any suggestions on what the problem could be?

It could be an assembly label or manufacturing oils burning off. Did it disappear?

The smoke only appeared at interstate speed. However, after cooling off for about an hour and driving in local traffic there was no smoke but he could still smell something burning.

If he can’t find anything visually using a good worklight and nothing else amiss, it’s probably a label. I’ve had this happen.

Buying a car for someone who is not even related to you.

Is that a bad thing? Or will everything be fine after the label burns off?

If it is a label, or manufacturing oils from the new assemblies, it’ll be fine once it burns off.

White smoke is likely water related. If the tranny was replaced I’d check the cooling lines for leakage. Someone should look at it ASAP or you could find the tranny needing replacement again very soon.

smoke could be totally unrelated to the recent work. could be.
If there is a small oil leak from the valve cover that drips onto the exhaust manifold, it will do this. Any small leak of fluid onto a hot surface will cause smoke and odor, are there any tell tale drip spots on the ground under where the car is parked? High speed = high heat.
You are the kind of mother of the girl friend I always wanted when I was in college, what a lucky dude.

Thank you. The smell seems to be disappearing so I hope it really is the label burning off.

We have not been able to tell if there are spots on the ground because unfortunately it has been raining. But we will have it checked and will ask that they check the valve cover. Thank you for your response.