Oil leak diag // Is it the 3rd line off the OFH?

[LappingLuke]

Hey M70 experts. I've been nursing a moderate oil leak in recent weeks (months?) just something that makes a mess of the garage but I'm not making a mess everywhere I go or anything. Originally I thought it was the lower oil pan gasket so I bought one but have been holding it for my next oil change which is due as soon as I get time. Last time I was under the car changing the belts and tensioners I looked around a bit and it actually seemed to be coming from higher up but its such a mess I couldn't narrow it down.

I got bored and was looking around with my flashlight and noticed where the 3rd line from the OFH goes into the top of the oil pan its utterly filthy and caked with oil/dust crud. I guess there is a barb and a bare hose end clamps on with a worm clamp here. Is this a common source of oil leaks on M70s? Should I consider replacing 11421731012?

Also, what is the function of this 3rd hose? Is that just where oil drains back to the pan when you remove the filter? or does it have another purpose?


Thanks in advance for the insight.
Luke

[cartoonz]

That is the bypass from the filter housing. Yes, that should be fresh but not likely going to solve your problem... Upper Pan Gasket

[rjjablo]

Upper Pan gasket, pull motor and transmission or Pull front suspension, both subframes, cut access holes in oil pan.

Either way you can also take care of all the power steering lines.

[LappingLuke]

Oooooooof I hope not

[cartoonz]

hope all you want... that's the leak.

[jimmythefish]

My 850i had an upper oil pan leak, and a bunch of others too from the pentosin reservoir. Pulled the tranny, replaced the RMS, I also did new gaskets at the back of the engine for coolant passages. I bought a brace from harbor freight to hold the engine up (changed mounts and ground strap at that time) and bought a tranny jack from harbor freight.I cleaned, cleaned, and cleaned…quite satisfying to see everything cleaned up from the lack of previous mechanics to clean during repairs. I purchased new exhaust hangers because of course they break. I changed all the lines from the pentosin reservoir as they were all weeping and deteriorated. My car now doesn’t leak a drop and the crude is out of the engine bay. Good luck!

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[LappingLuke]

Guess I better plan to replace these engine mounts at the same time then. Would be dumb to squeeze them in "the easy way" and then drop the subframe later for pan gasket.