2000 Bmw 740il

[carnraj]

Purchased this 2000 740il with 54000 miles in nov 03, car has never been a problem, doesnt burn oil or leak anything until 3 weeks ago. When starting anytime during the day after starting there is a large cloud of smoke . I have had this back to bmw 3 times with no help, they change the exaust manifold gasket and did a drip down test which was normal. This car is beautiful but the constant smoke at starting makes it look like a clunker. Car doesnt smoke while driving, only when you start or after you idle for a while, it seems like oil is driping into the exaust from some internal engine area. If Bmw cant find out the problem who can. Can i go to any agency to make them solve this problem. My warantee company wont pay for a teardown and bmw wants 2000. to do the work. I have no faith in there ability to find the problem. Can someone suggest something. thanks

[balmgren]

Could possibly be the crankcase ventilation membrane. Tricky to change but chep to buy. This sits at the rear of the air intake manifold, tight against the firewall, and is a common fault but normally only at higher mileages. I would suggest just changing this and see what the result are.