M43 Possible engine problem

Kenhayes247

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Jun 17, 2019
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79
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Meissendorf, Germany
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3
Hello all,

Slowly but surely my car is almost ready to be put back on the road, after chasing down an ABS/ASC fault "Thank you all" for your input, during the sorting out of that particular issue another problem may have/be occurring.

So I have a small amount of white/greyish smoke from the exhaust. Its not thick white smoke, its more like the smoke you get when initially starting up however even when the car is at temperature its still there.

There is no oil in the coolant, there is no indication of coolant contamination under the oil cap or on the dipstick. The coolant level doesn't appeared to have dropped. The exhaust fumes do not have that sweet smell associated with the of burning coolant. The engine has/is not overheating.

Today, starting with a cold engine and the filler cap removed from the expansion tank (I was going to check for bubbles with the engine running) i noticed instead that coolant was gently flowing from a small hole in the filler neck back down into the expansion tank, as the revs increased so did the flow. I have never noticed that before, its that normal? (An after thought - Could the engine be pushing combustion material into cooling system flowing into the radiator which as it expands pushes the coolant through the small hole in the filler neck)?

I have ordered a replacement PCV just in case there is a fault with the current one, is there any other areas worth looking at before compression or leak testing?
I can't see this being related but i did change the crankshaft sensor yesterday as the original one failed.

Yesterday was quite a humid day, today not so much but the emittance is still there.
 
Last edited:

t-tony

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British Zeds
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Torksey Lock,Lincoln, England
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E89 Z4 23i Auto
The coolant flowing as you've seen is quite normal Ken. Some thermostats used to have a "jiggle valve" which did the same job. I would suggest the vapour you're getting is just condensation which will go after a good run.

Tony.
 

Andyboy

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Jun 2, 2019
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As above. BMW's - especially four cylinder ones - can be buggers for steamy exhausts. On a cold winter evening they can be like the Orient Express.
 
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