BMW X3 mystery exhaust

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 exhaust smoke behind me. It’s happened on the ame stretch of hwy. each time. It goes away after about 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. Should I panic?

What color is the smoke? Rocketman

Blue Gray or white?

You don’t mention mileage,this important. After 50,000 it is possible that the crankcase vent valve is ruptured and oil is getting sucked into the intake.

I guess the problem fixed itself. Can’t figure how folks post questions and never follow up. Rocketman

It’s hard to say, it looks almost like snow off ones roof. White to grey, nothing unique.

White I believe.

27,00 miles.

I’m back…was working 2 shifts yesterday.

White is moisture and may be nothing more than an indication of the weather, or it may be a cooling system problem. Check the level of your coolant.

I’m taking it in to the dealer next Thursday…I’ll mention this advice. If it is coolant, does that mean head gasket?