Smoke Test Results for Rough Idle

[rjjablo]

I had my 1991 BMW 850 smoke tested, I had one leak thru the throttle body and Shogun has already provided the fix for that

This one is around the Oil Filler. Is this a front timing chain cover type of fix or has someone else seen what this is

https://youtube.com/shorts/4o26_HLVNpk?feature=share

[LappingLuke]

Hard for me to see. is the smoke coming from the seam where the filler bolts down and the engine? or coming out the cap? Also, shouldn't the PCV system check flow from the manifold to the crankcase and only flow from the crankcase into the manifold? Seems like that should not be happening at all.

[rjjablo]

Hard for me to see. is the smoke coming from the seam where the filler bolts down and the engine? or coming out the cap? Also, shouldn't the PCV system check flow from the manifold to the crankcase and only flow from the crankcase into the manifold? Seems like that should not be happening at all.

PCV Valves are three years old

[jimmythefish]

From the video, is the smoke coming from under the oil fill cap and possibly a bad seal under the plastic piece that the oil fill cap mounts onto the upper timing cover? Easy fix, then see what is left to see if the timing chain cover itself is leaking.

[rjjablo]

From the video, is the smoke coming from under the oil fill cap and possibly a bad seal under the plastic piece that the oil fill cap mounts onto the upper timing cover? Easy fix, then see what is left to see if the timing chain cover itself is leaking.

Went out and looked. There is a fancy rubber O-Ring that is between the front timing cover and where the oil cap is. I am going to get a new one, original is 31 years old and I am sure it is baked hard.

Looks pretty grimy on both sides of the cap so I am getting oil vapors leaking out of the crankcase, like you said, its a matter of where. Valve cover gaskets are 3 years old also