Suddenly leaking a lot of oil from air filter housing - Help!!!
 

I've owned my '79 240D for over two years now... and this problem started happening a couple of weeks ago: even after a short trip, there is a large puddle of engine oil on the ground, as soon as 10-15 minutes after parking the car (and the oil keeps dripping, at a decreasing speed for several hours).

I immediately found out that the oil was dripping down from the small holes on the bottom of the air filter housing, that is, coming out of the manifold intake underneath the air filter housing and being pushed through the air filter (which gets totally soaked with oil), then accumulating there and leaking out of the tiny holes.

First thing I did was to clean out the filter housing and put in a new air filter, thinking that perhaps the old filter had been clogged and thus causing the problem. No use: that same evening, same puddle of oil near the front right wheel. Next I tried changing the engine oil (perhaps the old oil was causing the problem, I thought) and, again, replacing the oil-soaked air filter with a new one. All the same, no use: the problem, apparently, is getting even worse with time.

Yesterday I took the car on a 100-mile trip on the highway. I stopped a couple of times for just a few minutes and each time there soon was a H-U-G-E puddle of oil underneath the car. After the trip I had to add 1 quart of oil to bring the level back to where it was before taking the trip.

Some time before this problem occurred, I had done a valve clearance adjustment - could there be any connection? Also, I had replaced the old air filter (a model that fit very loose) with a new one that fit more tightly (the filters I put in after that have been of the tighter kind).

The car performs great, is very powerful and sounds good...

What is going on? :confused:

Rino

Sounds like somethings clogged somewhere, blow by? Any oil leaking past oil cap?

There is no oil leaking past oil cap (or breather elbow connection).
The car has always had blow by since the time I bought it...

Could this problem be caused by the tighter type of air filter I've been using lately?

Also, should I look under the valve cover to see if the valve clearances have gone out of proper adjustment (therefore causing some reason for the engine pressure to rise...)?

Does it make any sense?

Check your crankcase vent tube, if that gets clogged pressure might build up and push oil up from the drain tube.

OK, I will tonight, thanks! :)

ok, have you checked the clear vent tube from the vacuum pump? if your vacuum pump seal is bad, you may have oil pumping from there. it's another thing to check.

Something odd about your description. Do you mean the air filter housing instead of the oil filter housing? There's an oil return tube below the air filter (I think) and it could have become disconnected from the pan.
Also a failed vacuum pump diaphragm (as already mentioned) will suck oil over into the air filter. There should be clear plastic hose going from pump to filter that should be turning black if it's sucking oil.

I third the vacuum pump. '79 has the diaphgram type, if the diaphgram fails that's what happens. The clear tube is the most obvious, you can also open up any of the other vacuum lines and see if there's crank case oil in them. If that's the case, address as soon as possible. You really don't want oil in your vacuum lines.

Don't think it would be a tighter filter, or valves. Hopefully your hose has collapsed, and replacing will solve. Certainly is something you need to address. Good luck.

Inspected it last night... it's not clogged at all.

I have never worked on the vacuum pump... I checked my repair manual and it says very little about it. I don't know how to go about it. Could you give some suggestions on how to do it, or point to an online tutorial or something like that?

Thanks so much...

Nope, it's just what I said... (unfortunately). The oil comes up the manifold intake (located under the air filter housing), goes through the air filter (which gets extremely soaked with engine oil) and then comes out of the two little holes that are at the base of the air filter housing.

The return tube you are talking about, I checked last night. It is perfectly connected at both sides and does not leak.

OK, I'll check later if the clear plastic hose from pump to filter turned black.

Thanks...

All considered, it's probably the case of a failed diaphgram then. But how do I go about finding out how to access the diaphgram and repair it? I would appreciate some pointers here. Thanks...

If you are talking about the breather hose that goes from crankcase to manifold intake, nope, I checked it last night and it is perfectly sound at both sides. It appears, according to what others have said, that the vacuum diaphgram has failed... Now I need to find out how to go about inspecting it and repairing it... Thanks...