Question about "smoke" on a 2017 M3 Comp

[greetoz]

Hi all,

Been reading the forums for some time decided to get an account when i bought a secondhand M3 Comp (2017) with 33.000 KM.

Very happy with the car but when starting the car again shortly after about an hours drive the person behind the car noticed quite some smoke from the exhaust. She asked if it was normal. I know it will produce some steam when cold starting as the water in the exhaust vaporizes. But this is when the engine has been running for while.

I did a short 15 min drive today then started the car again it produces some smoke when revving a little bit, it was a little bit more after the hour drive.. I'm not to concerned about it and the car behaves normally but as the car has 2 years BMW warranty better safe then sorry.

here a small clip https://www.youtube.com/shorts/YWQD1wgQIko

it was about 8 degrees celcius outside.

Thanks!

[TopJimmy]

Common in colder months for a little water condensation in the exhaust pipes. On start up you get a little steam out of the exhaust. A minute after start you can give a gentle rev and then go see if your exhaust tips are wet or water dripped off. If you catch the water in a pan you can feel if it’s oily or not (not usually, just smells like exhaust).

[greetoz]

Originally Posted by TopJimmy

Common in colder months for a little water condensation in the exhaust pipes. On start up you get a little steam out of the exhaust. A minute after start you can give a gentle rev and then go see if your exhaust tips are wet or water dripped off. If you catch the water in a pan you can feel if it’s oily or not (not usually, just smells like exhaust).

Thanks. Just to clarify, this also happens with an already warm engine/exhaust.

[TopJimmy]

White is ok as long as it’s not oily and goes away in a few seconds, and the radiator reservoir isn’t going down.

If it were blue or gray then it’s a problem.

[gerri]

When the outside temperature rises, you won't see it anymore.

[Soul Coughing]

This looks completely normal for the conditions. Part of the combustion reaction creates water, and due to the lower outside temperature, the warmer water in the exhaust condenses when it hits the cooler air. This is similar to when you breathe in the cold and you see your breath in the air.

[greetoz]

Thanks a lot everyone!

[khoa@x-ph.com]

White smoke is very common during the cold, as long as it's not gray or black.

[evoix]

Doesn't look bad. Check coolant level and see if the exhaust has a sweet smell to it.

If coolant level is fine i would say you should be good. Nice color.