2005 BMW Mystery Exhaust updated

I own a 2005 BMW X3 w/ 3.0 6-cyl. engine. After drivng in 6th gear at about 55 mph for three miles or so I noticed that sometime during acceleration to 65-70 a huge cloud of white exhaust smoke behind me. It’s happened on the same stretch of hwy. each time. It goes away after about 5-10 seconds. The oil level is fine, no sign of buring oil. The dealer can’t get it to do it. They say it might just be unspent fuel. The car has only 27,000 miles on it and the facotry warranty runs out June 30th. Should I panic?

You did not update your post you merely posted again. What significance do you put on it happening “on the same stretch of highway”.

Fuel should be blue in color. White is moisture. How long has it been driven when it gets to that stretch of highway? Has it rained recently before it happens?

I’m not sure about the weather…the times it happend it was below freezing. Winter here in Wisconsin. It was relatively dry outside I believe.

I guess I found it an odd coincidence. My thought was low rpms for three miles, then acceraltion in 6th gear meant something.

About 15 miles for length, but three miles after a brief stop to pick up my daughter.

What Dealer do you go to in WI.? I worked for Concours Motors in Milwaukee,you will be treated fairly.

I suggest you try replacing the PCV valve. I think that will clear the trouble.

Yes! panic to the point it gets fixed under warranty.

Appleton, WI, Bergstrom Enterprise BMW.

His BMW uses a cranckcase vent valve mounted on the back of the intake manifold,no service interval,they do rupture but failure before 50,000 is rare,I did suggest this when the OP started his earlier thread. No typical “rattle type” PCV.