M20 Oil leak diagnosis help needed...

[mitchc]

My kid's '90 525/5 started running really rough and dying recently after she overheated it. It starts easy but stumbles and sometimes dies when activating the throttle pedal. I brought it home and began trying to diagnose: Check to be sure the coolant had no signs of oil contamination; cleaned plugs; cleaned AF sensor; checked compression (approx 160# per cyl). I have yet to spray some cleaner on the Crank Pos. Sensor and check the idle ctrl valve.

I found a streaming oil leak on the Exh. side of the head, which seems to be coming from the fwd side of the #3 exhaust port, right above where the block bulges up like there is an oil passage cast into the block (this "bulge" seems to run from bottom to top).

Does it sound like the oil leak is from a leaking head gasket due to the overheat, even tho the compression is okay? And The stumble- could that be from a bad sensor somewhere or ICV? Seems to me to be two different problems, am I headed in the right direction?

TIA

Mitch

[Yaninnya]

I found a streaming oil leak on the Exh. side of the head, which seems to be coming from the fwd side of the #3 exhaust port, right above where the block bulges up like there is an oil passage cast into the block (this "bulge" seems to run from bottom to top).
Does it sound like the oil leak is from a leaking head gasket due to the overheat, even tho the compression is okay? And The stumble- could that be from a bad sensor somewhere or ICV? Seems to me to be two different problems, am I headed in the right direction?
It is looks like gasket gone. The compression can be o.k. because it is leaking from oil gallery (most probably).
Jan

[DaveVoorhis]

The stumble could be due to the crankcase vacuum leak caused by the failed head gasket, assuming it is a failed head gasket. Make sure the oil isn't drizzling down from a baked and failed valve cover gasket, which will also cause a vacuum leak.