Hey guys, I'm trying to track down a coolant leak on my wife's 1998 v90. coolant is dripping off the oil filter. Up top, I found a good leak at the thermostat housing. I replaced the t-stat and resealed with a light bead of grey permatex. Took it for an hour-long drive, and it's not leaking any more. went underneath the car and saw a little bit of wetness coming fro another part.

Let me know if you can help me ID this thing: right above the oil filter hookup, there's a little rectangular plate that's held in by two big torx bolts (their pointed toward the front of the car). My guess is that there's supposed to be oil behind that plate, and the coolant that I saw on there was probably dripping down from above. But it wouldn't be the first time I was wrong.

Please help!

Not sure what that plate is. Sometimes tracking the source of a leak can be difficult and requires carefull observation. Other times a pressure test of the coolant system will quickly reveal the leak.
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David Hunter

Yeah, I know what you're saying. Turns out that after I fixed the leak at the t-stat, I was chasing a phantom leak. I didn't realize how slow to evaporate coolant is. So i laid under the car with a rag, and dabbed up over drop of the stuff that was still clinging to bolts, gaskets, hoses, etc. Finally got it all and too the car for a drive. No more leak.

As for what's behind that plate... I swear I've seen an exploded diagram of the oil cooler before, but I can't seem to find it anymore. My guess is that it's oil.

If I understand your discription correctly the plate you are refering to is an oil bypass which on the early 960s was where the adapter for the air cooled oil cooler was.

On the later engines a water cooled oil cooler is sandwiched between the engine and the oil filter adapter. This is fed by hoses from the cooling system off the pasenger's side of the engine. It has the advantage of helping warm the oil quickly when the engine is first started.
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'96 965, 16' wheels, Michelin Pilot Sports, rear 18mm bar + Koni, 201 HP cams, 149K. Put 200K on '85 745 TD.

thanks for the info J! i had no idea.