[rs911t]

The saga to date ...

I notice greater the usual oil leakage a couple weekends ago. Put the car
up on jacks, pulled the right hand exchanger and the case and surrounds
down to dry metal. Ran the car (still on the jacks) and looked to see
where the oil originated. It was dripping at the engine oil cooler, at the
engine end of the tank return tube. I pulled the cooler, took it to Curry's
and had it pressure tested. The result was good - no leaks found.

So, I recleaned the case, reinstalled the cooler (with seals that were new
as of last summer), refilled with oil, added UV dye and tried again. The
results were the same, but narrowed the leak down again to the cooler
where it mates to the engine. A little good news - nothing coming from
the tranny bell housing. Thinking the oil cooler itself wasn't leaking, I
bought new seals.

This morning ...

I exactingly cleaned the engine/cooler mating surfaces and repeated the
reinstallation procedure with brand new seals, being particularly careful
the seals are correctly aligned and nuts carefully torqued.

By now I'm getting pretty darn good at field stripping the oil cooler with
the engine still in the car. I have no doubt I could do it blindfolded. But, I digress ...

Started the car and watched - same result.

This time I paid attention to when it started to leak, which wasn't until the
engine had warmed quite a bit, once oil was pumping thru the cooler. It
must be a leak in the cooler core itself, regardless of Curry's finding.

Before I purchase a new oil cooler, does anyone have an alternate theory?


Btw, this isn't fun anymore ...

[GB83SC]

Did you try some Dow Corning 111 ( non curing sealant) on the seals itself?
I used it last time I instaled new seals and have had no problems.
I have some extra if you need it.

[rs911t]

George:

I considered using silicone sealant on the metal-to-metal mating surfaces,
but decided against it. Did you have the same type of leak before using
the sealant? Is this SOP when installing seals?

I've concluded this leak has been present since I acquired the car, which
is why the seals were replaced last summer.

Anyone else use sealant on the seals and/or metal mating surfaces?

Thanks

[GB83SC]

Greg, There is alot of information on Pelican, do a search on (Dow Corning 111) It comes up alot on treads that have pesky oil leaks.
Good luck.

[Jim Richards]

Greg, when I had my engine out last spring, I pulled the oil cooler, cleaned it, and reinstalled it with new seals but without using any sealant. I don't think it should be required.

According to the shop manual, all you need to do is (1) ensure milled faces on the oil cooler and crankcase are in good condition and (2) use new sealing rings when refitting the cooler. From Wayne's (PP) book, the torque values should be: 25 Nm and you should be using nylock nuts.

[rs911t]

Thanks Jim. That's what I figured.

The faces are in generally good shape, but surely not perfect. Given the
cost of a new cooler, I'm going to pull it, pressure test it again and if it
passes reinstall with silicon sealer on the metal around the passages.

[Jim Richards]

Hope that works out well for you Greg. Watkins Glen is quickly approaching.

[rs911t]

I guess one of those good news, bad news kinda things. I rigged the
cooler to the air compressor with Justin's leak down tester and charged
it to 30 psi. It wasn't dropping, but I could hear it hissing. Put it in the
sink and guess what? BUBBLES! So much for Curry's diagnosis...

Anyway, need to procure an engine oil cooler ...