Comment by cucumber3732842
1 month ago
White smoke is water vapor. It's a normal byproduct of hydrocarbon combustion and tends to condense in the exhaust at low loads or immediately after exiting the exhaust, especially in colder temperatures, so you'll see a lot of it in stop and go traffic.
If it "reeks" though it's not just water vapor. I see a lot of these cars too, and you can tell it's been going on for a long time when the back of the car is covered in a layer of black grime. I think that's what kind of car problem the post is referring to.
> White smoke is water vapor.
Could also be coolant or oil
Even the faintest bit of oil will turn the smoke blue.
Could be coolant, but "coolant into engine" failure modes are generally rare and are usually the kind of thing that needs to get fixed promptly.
Coolant will have the dead giveaway sweet smell.