Getting oil in the Intake

[tintrx]

My E34, with M20 motor, is passing oil into the intake and getting as far a the the air box. This current motor has about 180k on it. The car runs fine during the warmer months in NC, except for an occasional bucking in the morning when I have the a/c running. Winter time presents a totally different cenario. Hard starts, that's if it starts. with ether starting fluid. I don't think that I have a bad piston ring. The car seems to run too good for that type of situation to exist. If anyone has any ideas about my problem. I would certainly appreciate some assistance. Thanks in advance

[tim eh?]

My E34, with M20 motor, is passing oil into the intake and getting as far a the the air box. This current motor has about 180k on it. The car runs fine during the warmer months in NC, except for an occasional bucking in the morning when I have the a/c running. Winter time presents a totally different cenario. Hard starts, that's if it starts. with ether starting fluid. I don't think that I have a bad piston ring. The car seems to run too good for that type of situation to exist. If anyone has any ideas about my problem. I would certainly appreciate some assistance. Thanks in advance

I'm not sure but I think it is normal to get a bit of sludge in the intake, it's normal for me anyway. May be an electrical issue if it is temp dependent ESP if the ac makes it worse.

[Ross]

Typically oil in the airbox is the symptom of a tired engine with lots of blowby or a faulty crankcase ventilation system.

[Grantus]

Check PCV valve and clean if required.

[tintrx]

Check PCV valve and clean if required.
Where is the pcv located, or is it the vacuum switch located under the throttle body?

[whiskychaser]

Typically oil in the airbox is the symptom of a tired engine with lots of blowby or a faulty crankcase ventilation system.
+1
IMHO a bit of oil in the throttle body is Ok. If its swamping the air cleaner box then its more serious

[Blitzkrieg Bob]

Where is the pcv located, or is it the vacuum switch located under the throttle body?

There isn't one....

Check your valve cover, pan gasket, and oil return tube.

If you have a massive vacuum leak through the crankcase then it will carry oil up into the intake, and it will flow down to the air box

[genphreak]

+1. That is the good oil on oil spewing into bad places... sometimes twiddling the oil return tube can re-seat a leaking o-ring. Any venting/leaking of the crankcase to the atmosphere can encourage blo-by, so check all your vacuum lines & connections too.

[tintrx]

I'll Check that oil return tube for leaks. That sounds like that might be the culprit. I'll get back 2 you and let you know what I find out. Thanks a bunch.

[tintrx]

Well it looks like I'm still hunting. I've changed the throttle body 2 valve cover hose it did have a crack in it which was causing a oil/vaccuum leak, but I'm still trying to find what's causing this eradict stumbling when the ac is on. any thoughts anyone?

[sal_park]

Does the M20 has an ISV ?

[tintrx]

I'm sorry. What is an ISV?

[sal_park]

Idle Stabilization Valve

[632 Regal]

the PCV or "cyclone valve" is the cover on the back of the intake and if busted will draw oil into the intake. In colder months if you hear a squeeling sound like a duck then the intake gaskets are leaking. If you have had the car for a few years and have problems in the cold than I would suggest to replace the back plate and gasket, the front plate gasket but not the plate (don't forget this one, I had 3/4 inch leak!) and the intake gaskets. Order the little "O" rings that go into the tubes from the front cover to the rear under the intake. It's pretty much a 4-6 hour job first time but not as hard as you would think. Actually simple but time concerning, don't fire up the beers until your deep into reassembly or almost done :-)

[genphreak]

Ah Jeff, the elusive PCV problem unveiled.

So is it number 7 that fails on an M20?

So http://bmwfans.info/parts/catalog/E30/4-doors/Europe/325i-M20/RHD/A/1988/october/browse/engine/intake_manifold_system/

Or is it 19 (just seems to be a part number-less pipe)

[tintrx]

My m20 motor doesn't have the ISV it has an ICV That is connected to the front of the intake at the throttle body. It does however have the back plate on the intake manifold which creates vaccuum to the fuel pressure regulator. I did check for vaccuum leaks around the the intake and throttle body. Nojoy. Without any other options, I'm starting to think pistons and rings. Any other ideas would be greatly appreciated.

[Mordan]

hello experts here.
could this be because of a failing rear oil seal? that's a hole in the crankcase right?
I also have a little oil in the air box and my rear oil seal leaks.