Vacuum in oil pan?

[Justbergy]

Is there vacuum in the oil pan of an e30. Like I have a small crack in my oil pan and was wondering if that is a problem. Like it's high enough we're oil doesn't ever come out. Just curious. Thanks!

[cscracker]

Yes, it's under vacuum. Any leaks in the oil pan or the dipstick are vacuum leaks.

[Justbergy]

Yes, it's under vacuum. Any leaks in the oil pan or the dipstick are vacuum leaks.

I thought the crank case was vented...?? like to the atmosphere

[digger]

its vented to the intake between the throttle butterfly and AFM so there is a teeny tiny bit of vacuum. its not on the vacuum side of the butterfly.

if its a hole then crap can get in from the outside even if oil doesnt come out

[cscracker]

Yeah, the crankcase vent is between the AFM and the throttle body, not to atmosphere. The whole crankcase is under vacuum. If you pull the dipstick while the engine's running (and you don't have a huge vacuum leak) it'll noticeably affect the idle.

[325e '87]

Yeah, my engine will come really close to stalling if the dipstick or oil fill cap aren’t making a good seal.

[digger]

Pulling the dipstick is NOT a vacuum leak it's unmetered air. It's not a vacuum leak because it's not on the vacuum side of the throttle butterfly

[cscracker]

Unmetered air is a vacuum leak. All air that gets in but is not measured by the AFM (or MAF/MAP sensor on newer cars) constitutes a vacuum leak (or air leak, technically vacuum can't leak, but it's common parlance). There is no difference whether it's before or after the throttle body, it will cause lean running conditions either way.

[zaq123]

Pulling the dipstick is NOT a vacuum leak it's unmetered air. It's not a vacuum leak because it's not on the vacuum side of the throttle butterfly

any benefit to route crankcase vent (CCV) to the intake plenum via catch can-foam filter into the intake plenum of ITBs? I remember deleting CCV on my old e46 and venting it to the atmosphere. It ran like crap so I had to put new cold weather CCV system in.

[digger]

I personally don't think there is a benefit except environmental reasons. There just isn't enough vacuum to improve performance