Oil Seperator
 

having recently lost my mechanic to cancer and not trusting my local dealer, i am forced to work on 2 e53 's myself. both are 4.4's '02 and '06. all this talk about oil seperators freezing up scares me. do they need to be cleaned or replaced? and where are they located?
thanks

The same rash of questions goes on every year, from early November through February. Then it goes quiet again until the following year.

There are lots of threads on the issue. Decide if you are in a high risk group, and if so, you may want to clean it out and inspect it.