BMW Repair: Coud of oily smelling exhaust on start up 99 740iL, intake manifold gasket, oxygen sensors

Question
Even,

My '99 740iL emits a cloud of gray-color exhaust smoke when it is started.  That is the only time it happens (after the car has been parked a few hours or more).  There is a distinct smell of oil in the smoke.

I have been told I need to spend ~$900.00 to replace the intake manifold gasket, to fix the problem.  Can this be true?  The same garage replaced one of the oxygen sensors to fix the same problem a few months ago - but the problem only gets worse.  For the first time, I have had to add a quart of oil between changes (Mobile One Synthetic).  I am OK with spending the money, but I need some reassurance that the symptoms are indeed related to the need for the intake manifold gasket, and not possibly other issues.  Thanks!

Mike

Answer
Mike, it shouldn't be $900.00 dollars. I charge 5-6 hours without the coolant valley plate. I would however recommend resealing the ENTIRE intake manifold (runner gaskets, front and rear plate gaskets, throttle gasket)  along with replacing the rear backing plate which contains the PCV valve that could be leaking. I can't remember if your motor has an oil vapor seperator or not. If so replace it aswell. If the coolant valley plate is seaping coolant now is the time to replace it too.
-Evan