Mist on accelleration Merc E400

[Matt Sussex]

Hi, I am probably being paranoid..... With certain temperatures outside I see condensation from my exhaust, not worried about that. But when engine is warm and I accellerate hard I sometimes see what may be water vapour in the air behind my car, Oil is clear, no white emulsion in oil or on oil cap. It is not always happening and generally notice when sun behind the car. Runs smooth as silk, does not get too hot or overheat. Hoping just this time of year and condensation in exhaust? Was thinking it smells a little rich by the exhaust, could that be an injector?

[paintman]

Get your emissions tested to check.
But burning a gallon of petrol or diesel produces - amongst other things - about a gallon of water.
It's got to go somewhere!

[E63eeeeee...]

Yep, that's pretty normal if mine is any indication. The first launch after a cold start regularly fogs up the back window.

[Tony1963]

I think that quite often water that is produced by the combustion process manages to sit in silencer boxes for a long time. On a long journey the whole exhaust gets hot enough to evaporate all of it, on some shorter journeys nope, and then there’s the in between journeys where the water will be hot, but is only chucked out the tail pipe under hard acceleration because of the increase in exhaust gas flow.
Sometimes you’ll be behind a car and see a full on flow of water pour from the tailpipe. Oh the things we’ll miss once the internal combustion engine becomes a rare sight…

[Matt Sussex]

Thank you, feel more relaxed about it now, mot in December and they will check the emissions then. Pretty certain it is just mist not smoke.