Originally Posted by Antiburn
Well you might want to panic a little bit since your pcv valve is going and a dealership will change you 8 hours labor to replace it. The milky nasty buildup on your oil cap is moisture entering the system via a torn rubber diaphram in your pcv valve. All the parts are under 100$ but the valve is located under the intake, which you can imagine is a PIA to get to, which it is.
if you let it go for to long then you can expect a rough start up when its cold, possibly some smoke out the exhaust.
BMW makes a tool which we call a "slack Tube" which it pretty much measures crank case vaccum. If you have a low amount of vaccum then your pcv valve will need to be replaced.
Depending on where you live I might be able to help you out and do the job for you for alot less then the dealer would charge.
so if you remove your oil cap while the car is on, and tis really easy to remove w/no resistance, then it is bad? because for me its really easy to remove, yet i definitely dont have any white stuff in my oil or oil cap, and whats this i hear about the valve 'hooting'?