I seem to have a leaking oil cooler. (heat exchanger) - 986 Forum - The Community for Porsche Boxster & Cayman Owners

elgyqc · 07-31-2023, 06:19 AM

After starting the newly installed engine in my 2000 Boxster S I found a fairly serious oil leak coming from the oil cooler, my first reaction was o-rings, even though I changed them while the engine was out. The engine was bought from a "recycler" so I have no experience with it.
Upon closer inspection I found this:

It seems to me if the o-rings were the problem the oil would be leaking out under the oil cooler and there would be no way it could collect in the "tray" that forms the bottom of the cooler where the bolts are. Also there is almost no oil on the top of the crankcase. I am therefore pretty sure that the leak is higher up and that I need to replace the oil cooler. I will do some more running to see if I can find the general area of the leak. Meanwhile can anyone see an error in my logic?

Homeoboxter · 07-31-2023, 09:01 AM

Seems like there may be a crack where the "tray" section is attached to the rest of the heat exchanger. Did you apply the correct torque values?

elgyqc · 07-31-2023, 11:56 AM

Quote:

Originally Posted by Homeoboxter

Seems like there may be a crack where the "tray" section is attached to the rest of the heat exchanger. Did you apply the correct torque values?

Yes, I'm pretty careful with torquing. But there is a dent in cooler on the top rear edge, maybe it took a hit when it was removed from the donor car.
I have another cooler from the engine that was originally in the car... but it is likely contaminated with bearing flakes like those I found in the oil pan.
There is an oil cooler on Amazon for about $60 CAN with a year garantie and 30 day return. I will likely order it.

Homeoboxter · 07-31-2023, 06:29 PM

That's the way to go. Good luck.

elgyqc · 08-01-2023, 11:56 AM

I cleaned up the oil cooler and started the engine, immediately there was oil leaking out half way up.

Mystery solved. Waiting for a new cooler.

elgyqc · 08-05-2023, 06:24 PM

The old oil cooler has this little ding in it right at the level where it was leaking.

... doesn't look like much.

Here is the new $50 oil cooler I got on Amazon installed and not leaking. Yeah!