I'm a little surprised to find there isn't more scuttlebutt about this on the board, unless my now-unaccustomed Brickboard fingers are not searching correctly.

This is a 97 T5. We bought it for a specific purpose almost exactly a year ago because it was in fantastic shape cosmetically. One of the last details I've yet to see to is the cold moan from the oil thermostat, which I know is NLA. Yeah, I can go yank one out of a yard, but I am wondering if anyone ever answered the question about whether this thing can be gutted, and if that solves the problem. The car has developed a small oil leak, and it's possible it's coming from the housing or hoses. Before I dive in, thought I'd investigate.

Cheers, Brickboarders.

I just finished replacing my oil cooler lines. Before starting anything, check both oil lines and find out which one is leaking, because the oil thermostat is probably NOT leaking. If you replace the line(s), try not to remove the thermostat as the replacement gasket tends to fall out, slip, as you are trying to put it back on! Plus, the forward T40 screw is under the serpentine belt and a 3/8 ratchet won't fit properly during install.

There is also that pesky 10mm bolt holding the oil cooler lines to the block. The sages all suggest removing the compressor bolt for better access. LOL. That 14mm bolt wouldn't budge for me. It took me 1 hour to remove the little 10mm bolt. Putting it back on? Lots of luck, unless you take off the intake manifold and reach it from above? Or have small hands to get it from below.

There is a T30 screw holding the cooler lines to the thermostat. Access to that screw is non-existant with the thermostat still in place.

You mentioned a cold moan from the thermostat? I have never heard of that before. How did you diagnose the noise emanated from there? The wheel has to be off and the cover lifted to verify the noise came from there. There is a flap in the oil filter that could make the same noise, same area on the car.

There is nothing serviceable in the oil cooler thermostat. A heat activated spring and rod.

Thanks Klaus. I did the cooler lines on the wife's V70 some months ago. Aside from the huge debacle with aftermarket lines that don't fit due to poor bending, yes, quite a job. I managed it with patience and lots of fiddling--universals and all that, but no fun. Had the OE hoses rebuilt.

I'm not convinced anything leaking that far "down" below where the majority of the oil is collecting could manage to travel so far, uphill (draft issues notwithstanding), but yes, have to get the wheel and air guide and all that off to see, I guess. There is no sign at all of any oil around any part of the crank snout. I'm more tempted to think it's the exhaust cam seal, perhaps running down behind the rear section of the belt cover, invisible, then finding it's way out onto the little ledge right below the tensioner. That makes more sense. Just looking for input. Yes, very familiar with the retainer plate and seals for the hoses, but you are correct, I found little evidence on the web of the thermo housing itself leaking. I hasten to say it's not a lot of oil. Initiall found it under the t-belt cover and found the majority of it when I took the top cover off.

The moan is something that's documented across the interwebs in a bunch of posts. Only cold, and that's exactly when mine is present. The oil and filter have been changed a bunch of times already (Mann), so not likely the filter. Something about the valve not closing completely and vibrating, if I understand correctly.

My car is doing the same thing regarding oil. While I had the thermostat off, oil would magically appear on the block where the thermostat housing attaches. This made no sense, where would the oil come from? The thermostat housing was dry and cleaned off, the engine had not run for a few days (I took time off to do other things while the car was on the jack stand).

I am also going to check the cam seals and the oil pump seal. The 'leak' isn't bad, one drop on the garage floor overnight after a 30 minute 'hot' run. Of course, when I disconnected the top cooler hose it leaked a lot of oil and will keep any rust away for a few years. To say nothing about pouring oil all over the sub frame. A real mess! I may even attempt to clean it up sometime.

Know anybody that wants a 1995 855T?

Curiouser and curiouser here. When I messaged, it was because the "moan" was somewhat related to the other problem, the leak. I cleaned things up, some, back then, to see if I could track it. Checked around the cooler hoses as best I could from above (which isn't very well, even with a mirror), seemed clean and dry there. Meanwhile, about a week later, the starter went out, which I had no time to see to. Finally got that taken care of weekend before last, after leaving the car parked for some time. Then, amazingly, a couple of days later, the car was a no start--no crank, dead as a door nail, with a good battery, and flashing upshift light on the dash. No codes, no warning, and no time to mess with it, again. It sat for another week before I could check the coil, which was fine. Leaned on the top of the fan shroud, looking for something to jump out at me and say "Hey, idiot, you didn't [insert whatever] when you did the starter". Checked connections, zip. Asked the wife to try it again...and it fired right up. Instantly. Leaned on the shroud, cut out. One of the "gummies" in the system relay's plug had deteriorated. I must have pulled it while reinstalling it when I did the starter, and it was only tight enough to give me one trip before slipping off the relay's pin.

At any rate, fixed that and did an oil change....and now find no sign of leaking oil in the back, above and behind the crank pulley, at all. Nothing. While underneath I took off the air guide. All dry around the cooler and hoses. Not a sign of any oil at the forward area of the engine. In back, nothing but the streaks from where I cleaned it off. Baffled. Leaks don't just stop. Cannot figure this one out, but I'm watchin'.

You will find out after running it 'hot' a few times.

When I bought the 1995, there was more oil than metal on the outside of the engine. I pulled the cam belt cover, what a mess! After changing the oil soaked T belt, I haphazardly cleaned some of the oil off the block. Then when I replaced the oil cooler lines, oil was very slowly dripping down to the thermostat housing. Checking the front cam seals, nice and dry, I can only assume that the oil was left over from the cooler line leak. I will have to take another look next spring, driving season is almost over in MN.

My new mechanic says there is a little leak from the RMS, and I don't want to go there!! At least I no longer have a dozen oil drips after every run. I put a bottle of stop leak in the oil, but I don't drive it enough to get it to work.

I like your discovery of the no-start. It's the little things that get over looked.

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Keeping it running is better than buying new