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White smoke when warm

Discuss problems you have had or are having with your Z4
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d3matt
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White smoke when warm

Post by d3matt » Sun Mar 19, 2017 3:26 pm

My 3.0 has done 112,000 miles.
When starting on cold and revving there is no smoke whatsoever. There's also no oil use. It runs very well.

Yet recently I've noticed that when stopping at the first traffic lights near my house, white smoke wafts passed me. At this point I've driven 2.5 miles and the engine is up to temp. Anything to be concerned about?

I've been reading about the crankcase ventilation today and wondered if its that. Never knew what it was until today. I've only owned the car for a year and have no idea if its been changed. Just watched this video to diagnose ccv issues and it shows resistance on the oil filler cap and a change in tickover when removed. Mine tickover certainly does change, yet there is little resistance/pressure when removing the cap. You can feel a slight suction, but it is very slight and only noticeable because I was looking for it.
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Chris_D
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White smoke when warm

Post by Chris_D » Sun Mar 19, 2017 3:31 pm

Best case scenario is that it will be just condensation, as it's still cool enough for that. Dark smoke you'd need to be more concerned with.
Check inside of oil filler cap for light coloured mayo substance. If present, think about swapping in a new CCV system. Infact, I'd go one further to suggest swapping a new CCV system in anyway seein as youre at 112k. If it's still on the original it's not a question of if the CCV diaphragm will fail, but when.
Swapped in a cold-climate version on mine when bought last summer and it cured the high oil consumption issue I was experiencing. PITA to fit but worth it
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d3matt
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White smoke when warm

Post by d3matt » Sun Mar 19, 2017 3:36 pm

Filler cap is spotless.
I had to replace the rocker cover gasket last autumn and I suspect that was the original, so I suspect the CCV system is all original too.
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VRSteve
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White smoke when warm

Post by VRSteve » Sun Mar 19, 2017 3:58 pm

Condensation in the exhaust

Don't worry about it
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d3matt
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White smoke when warm

Post by d3matt » Sun Mar 19, 2017 5:12 pm

Relief. Thank you.
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firebobby
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White smoke when warm

Post by firebobby » Sun Mar 19, 2017 11:26 pm

If it's burning oil, it would do it all the time, you would notice smoke from the exhaust all the time. If not, it sounds like condensation, how long are you daily journeys ?
If your doing short trips, the engine/exhaust won't get hot enough to burn the condensation off and the exhaust can hold quite a bit of water, so you get steam/
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Silverzedtom
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White smoke when warm

Post by Silverzedtom » Sun Mar 19, 2017 11:58 pm

sounds normal. Takes a while to get the exhaust hot. Also don't forget if your comparing to other cars that most cars on the road have smaller engines than our cars... smaller engines = less exhaust. Less exhaust = less water vapour content.
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TONYMOR
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White smoke when warm

Post by TONYMOR » Sun Jan 29, 2023 8:36 pm

Mines a 2.31 and seems to do it more often even if the engine is up to temperature?

FunkyGBrown
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White smoke when warm

Post by FunkyGBrown » Thu Feb 02, 2023 11:07 pm

How long are you driving it for when checking?

Mine does this, stopped at some lights on the morning commute and saw what looked like plumes of white smoke. I've checked it over with a friend and all seems fine mechanically. Did further reading and lots of accounts of the same thing with the cause being condensation on the exhaust.

Did a longer drive one weekend at a similar time and it disappeared after half hour or so of motorway driving.

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