[tirwin]

Richard,

A few thoughts...

The top two openings in the oil cooler are the only ones under pressure. The bottom one is gravity fed only (no pressure). When I did this I found there were a few discussions about problems with certain replacement sealing rings. If memory serves, the green ones are bad and the reddish brown ones are the ones you want to get. I can't remember where I got them but it was a little tricky to find them. Maybe it's in one of the threads. I can try to look back through my invoices if you need me to.

Porsche issued a TSB on oil leaks by the oil cooler. This has been covered a few times and should come up in a search. If you look at where the oil cooler attaches to the engine case you will see a line where oil has leaked. You'll see a little dimple and that's the problem. Clean that area with a degreaser and then fill the dimple with JB Weld and you won't have a problem anymore. EDIT: I looked at your oil cooler pic again and that looks to be EXACTLY your problem. See where you have a big spot of grime near the big opening at the bottom. That is exactly where the dimple is that needs to be filled on the engine case side.

Check the triangle of death area on top of the engine. It's possible you have a leak at the oil pressure switch or maybe the hose came off the case vent and ran down that way. Or the seal around the case vent is leaking. Or the thermostat o-ring is leaking. All 3 are common culprits.

If you really want to clean up your fan, consider sending it to Mark Motshagen. Search for my thread "Mark Motshagen is a real craftsman" to see his work on my car and others.