1997 BMW 540i

Engine Performance problem
1997 BMW 540i 6 cyl Two Wheel Drive Automatic 98500 miles

On startup will run just a little rough. After about 2 miles a strong smell like a heater kicking on for the first time comes into the cabin followed by a large amount of white smoke billowing from the exhaust. Quits after about 15 seconds.
There is no coolant mixing with the engine oil and I sprayed the engine to see if there were any leaks and did not find anything. The engine runs fine and there are no warning lights.
December 17, 2009.

Your description sounds like a cooling system leak, a pressure test overnight with the spark plugs out will see if it is pushing coolant into the cylinders.

Dr. Hagerty
Dec 19, 2009.