5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
My wife drives it and assured me she has not run through big puddles. This only happens if it is raining so it's only very high humidity that causes it. It runs very rough and spews white smoke. If you try to drive it, assuming it continues to run, it has no power. My mechanic, who specializes in German cars and has always done a great job with the car, thinks it may be caused by a blown head gasket resulting from one time when the car overheated (not severely) after the plastic radiator tank cracked. He thinks it may be only 'moderately blown' but has not done a compression test. Yes, there is a little bit of coolant loss and a bit of brown goo on the dipstick that resembles an oil-and-water mixture. Whether he's right or not, I don't see how that could be affecting only high-humidity driving. The car starts and runs great the rest of the time. No missing at all and plenty of power.
Yes, it happens when it's cold and yes, the goo is sorta beige. So that may confirm the head gasket diagnosis but would that explain the hard starting that ONLY occurs when it's very humid and no other time?
Difficult starting when humid will just be a MAF issue I think, as the air quality is much denser and the sensor will be reluctant to give the correct signals to fire... Just my thoughts!!
Good luck with the H/gasket my friend ;-)
Eso es todo! Please press the "REP" button if you are happy with your response/answer...
Thanks. With good power and driveability and smooth idling - most of the time - I have to believe that if the head gasket is blown, it's surely a 'minor' blow. So for this, I've been told Bar's Leak Stop is worth a try, after I do a good flush. Your thoughts?
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.