Oil level in the oil filter housing

[yaofeng]

I changed oil for the first time on my 525 a number of weeks ago. I noticed the oil level in the filter housing never dropped. Not knowing how to drain it, I kept the old oil in the housing after replacing the filter.

Yesterday, I opened the oil filter housing on the 540 hoping it will be empty. I wanted to pull it to gain access to the driver side engine mount nut. The 66k engine has not run since coming to my house in April. Although I did crank it on the stand testing compression after cleaning it up and filling it with 8 qts of Mobil 1. When I again found it full of clear, new Mobile 1, I gave up the idea of trying to pull it.

Anyway, what's the idea of a full oil filter housing? How can you drain it?

[Blitzkrieg Bob]

in there to suck it up.

[yaofeng]

I think you are serious. Are you not? Is there really no way to drain the oil?

[Blitzkrieg Bob]

element, the oil level drops down, I just soak it up with a rag.

The check valves keep oil in there, so it doesn't completely drain down.

[ryan roopnarine]

the housing holds the oil in until you open the drain plug, then the vacuum pulls it out.

[yaofeng]

So I should have opened the oil filter housing before pulling the drain plug. Is that right?

[Bellicose Right Winger]

The oil filter housing is supposed to drain into the oil pan when you remove the bolt that holds the lid on the housing. Notice the o-ring at bottom of bolt? It prevents draining when engine is running. You must have a blockage or perhaps this is related to trying to drain cold engine oil which is much more viscous then when hot.

Paul Shovestul



I changed oil for the first time on my 525 a number of weeks ago. I noticed the oil level in the filter housing never dropped. Not knowing how to drain it, I kept the old oil in the housing after replacing the filter.

Yesterday, I opened the oil filter housing on the 540 hoping it will be empty. I wanted to pull it to gain access to the driver side engine mount nut. The 66k engine has not run since coming to my house in April. Although I did crank it on the stand testing compression after cleaning it up and filling it with 8 qts of Mobil 1. When I again found it full of clear, new Mobile 1, I gave up the idea of trying to pull it.

Anyway, what's the idea of a full oil filter housing? How can you drain it?

[yaofeng]

The oil filter housing is supposed to drain into the oil pan when you remove the bolt that holds the lid on the housing. Notice the o-ring at bottom of bolt? It prevents draining when engine is running. You must have a blockage or perhaps this is related to trying to drain cold engine oil which is much more viscous then when hot.

Paul Shovestul

Blockage as in what? My 525 is running just fine.

[winfred]

loosen the oil filter housing top first then go under and pop the plug, the housing will drain down with the top loose as that breaks the vacuum, this holds for all the bmws i work on

[Bellicose Right Winger]

Blockage as in an obstruction in the drain hole that's at the bottom of the oil filter bolt. With engine warm, remove the oil filter bolt and lid, remove the oil from housing, inspect bottom of oil filter housing for foreign material, poke wire into hole that oil filter bolt threads into. This has no effect on running characteristics, only the ability to drain the oil filter housing.

Paul Shovestul



Blockage as in what? My 525 is running just fine.

[yaofeng]

Blockage as in an obstruction in the drain hole that's at the bottom of the oil filter bolt. With engine warm, remove the oil filter bolt and lid, remove the oil from housing, inspect bottom of oil filter housing for foreign material, poke wire into hole that oil filter bolt threads into. This has no effect on running characteristics, only the ability to drain the oil filter housing.

Paul Shovestul

I don't think you get it. I removed the drain plug on the sump first. After oil is drained I then removed the oil filter housing cover. That is why oil won't drain. Had I removed the oil filter housing cover first before pulling the plug from under, a vacuum would have been created to open the check valve to drain oil in the filter housing.

[Bellicose Right Winger]

This is very strange and perhaps I don't get it. I drain my oil the same way you do, except my engine is at operating temperature. I remove the oil pan drain plug before I remove the oil filter bolt. I never have any trouble draining the oil filter housing on my '90 535i, '93 525i, '98 M3 or the '00 528iT. Even on the occasions where I've had to remove the oil filter bolt to replace a leaking o-ring, with the oil pan full of oil and the drain in place, the housing drains fine. The oil filter housing drains because a passage is opened when the bolt is removed. There is no check valve involved, there is no vacuum created or needed, and in my experience the drain sequence doesn't matter. This is why I suspect you have a blockage of some sort.

Paul Shovestul




I don't think you get it. I removed the drain plug on the sump first. After oil is drained I then removed the oil filter housing cover. That is why oil won't drain. Had I removed the oil filter housing cover first before pulling the plug from under, a vacuum would have been created to open the check valve to drain oil in the filter housing.

[ryan roopnarine]

I don't think you get it. I removed the drain plug on the sump first. After oil is drained I then removed the oil filter housing cover. That is why oil won't drain. Had I removed the oil filter housing cover first before pulling the plug from under, a vacuum would have been created to open the check valve to drain oil in the filter housing.

you might actually have a problem there. i'm pretty certain that the oil should drain out of the canister any time the sump is unplugged. what i was trying to get at was that you should not expect the cannister to completely empty itself out if you only opened the cannister. i still have a decent amount of oil remaining in there (not full, of course) when i crack the lid, but it goes away when i open the sump. if i close the sump before i put the lid back onto the oil filter, i can prime the filter by pouring motor oil into the housing, and not have it drain.

[yaofeng]

Maybe I do. That was my first oil change about a month ago. I didn't stand there and wait for the oil level in the filter housing to drop after that in the sump has already been drained. Maybe the drop was very slow. I didn't have the patience. I pulled the oil filter to put a new one in and closed it up.

[SnakeyesTx]

8 quarts?! My manual says 6! Did you change pans or something?

[yaofeng]

8 quarts?! My manual says 6! Did you change pans or something?

The V8 wants more of everything.