Oil not draining from oil filter housing

[rajicase]

I recently bought my first BMW, a 1995 M3. I have been fixing various issues with it, and today was oil change day. First time changing the oil in this car. I took the drain plug out, and while the oil was draining I open up the oil filter housing and replace the O rings and washers. Before I replace the filter I want to wait for the oil to completely drain from the housing, but it wont drain. And I am not talking about a bit of oil at the bottom, it was almost completely full. Common sense tells me that it should drain, but it wouldnt.

So I just put a new filter in and filled the car back up with oil since I didn't see any other options at the time. But there has to be an answer to why the oil didn't drain out of the housing, and I would really appreciate any insight.

Sorry if this is a stupid question or common knowlege, I searched for answers but couldn't find any.

[nighthawk328i]

I don't have the correct answer for you as i've never experienced this. Just out of curiosity, did you loosen/remove the oil filler cap while the oil was draining?

[rajicase]

No the filler cap remained on until i got frustrated with the oil not draining, and I plugged everything up and put fresh oil in it.

[fsmtnbiker]

Was the car/oil hot or cold? I've seen the housing not drain if you try to do an oil change while everything is cold. It isn't *supposed* to drain the housing at all unless you pull the lid, but even then the passage to drain it is very small. If the car is warm it isn't a problem, as the oil flows more easily.

[rajicase]

I made sure the car/oil was hot though.. Hmmm

[RabzorGT]

Hi
Did you fix your oil draining problem?
Would appreciate if you can update this thread.

Regards

[rajicase]

Wow, man I remember this.
No, that s50 always did that and it was never an issue. I put about 30k more miles on that engine and it ran like a top before I money shifted and blew it up!
Good luck!

[RabzorGT]

Hi,

Thanks for your feedback that confirms the good working of my car (and RIP S50 )

Regards