Are you still under the factory warranty? If your X5 is behaving so badly, call up BMW road assistance, have them bring out the flatbed, and have the service department take a look.

Regards, Mike

Is there anyway you can get under the car and check for exhaust leaks?
look out for black smoke residues around the exhaust.

Burned oil would be blue smoke. White/Grayish smoke are signs of a blown head gasket (aka anti-freeze is mixed in with the oil).

Blue smoke????Never seen that and I work with cars everyday!Seen blue flames coming out of the exhaust of turbo charged cars that have their mixture too rich!

Burned oil will always show white /grey smoke.

That doesn't match with the old mechanic's standard rule of thumb:

Black smoke is overfueling
White smoke is water in the combustion chamber, usually a head gasket
Blue smoke is oil passing the rings or valve guides

Jeff

I'm with JCL: I've seen alot of "blue" smoke emanating from
tail pipes over the years.

I therefore must be colour blind then!