Help: e39 540i PCV/OSV issue

[Lungs033]

My 2002 e39 540i is on 255k km. Car idles and drives fine except for a puff of thick white smoke on start up and occasionally while driving.

I purchased a replacement PCV but only replaced the cap and diaphragm on the back of the intake. The smoke stopped but the PCV started giving howling/vacuuming sound and the vehicle is still consuming oil.

I'm thinking maybe if I replace the whole PCV on the back of the intake my issue may be resolved.

Alternatively I will install a oil catch can if the issue is with the OSV behind the timing chains.

Has anyone encountered this problem and resolved it?

 

[Peter@AEW]

Replace the whole back plate and change O rings on oil transfer tube from PCV to front of head.

 

[Lungs033]

Replace the whole back plate and change O rings on oil transfer tube from PCV to front of head.

thanks Peter@AEW, does the transfer tube have o rings on both ends?

 

[Peter@AEW]

thanks Peter@AEW, does the transfer tube have o rings on both ends?

A blue O ring on the joint of the PCV valve and transfer tube.
Best way to replace is to remove the plenum and change gasket on the PCV as well as the O rings.
This will also give you the opportunity to drain the oil out of the plenum.
Worth the effort imho.

 

[Lungs033]

Thanks @Peter@AEW I'll definitely try that route.

 

[Benji]

E39 did not have OSV problems like the E34. The howling points to an air leak, check also that the unused vacuum ports on the PCV are plugged. With the engine running, you can dig around there (maybe spray some brake cleaner) to try find where the leak/howl is coming from

 

[Lungs033]

Thanks @Benji, ill definitely look at it and replace the brittle vacuum lines while at it.