Mishimoto Oil Cooler sandwich plate leaking oil
 

Update: Ended up re-installing and re-torquing, no oil leak until a full week of driving, which is a massive improvement but after speaking to some very knowledgeable individuals they said it's unfortunately the nature of sandwich plates to leak a tad bit. They checked mine personally, felt the oil, and said I had nothing to worry about.

I'm wondering if someone else may have had this issue before. I've had the Mishimoto oil cooler on my boosted BRZ for a few months now and its been lightly leaking oil from the sandwich plate since day one.

I contacted them about the banjo fittings and they made me purchase replacements. I did so and re-installed properly, and after a few days the leaking happened again. For context I've installed 2 Mishimoto sandwich plates prior on 2 different boosted BRZ's with my friends, theirs haven't leaked - Following the issues I did all my installations with my Subaru tech friend present.

This time I took the sandwhich plate assembly apart, re-installed properly, and as I torqued down the plate to 30 - 34ftlbs the top spacer cracked on itself. Mishimoto graced the warranty and send me two new spacers.

I went ahead an carefully re-installed the assembly, oiling the rubber gaskets before application, properly torqueing to 30-34ftlbs, and here we are, still leaking oil.

It's extremely minor how much oil is actually leaking, it's like a light layer of oil building up on the bottom side of the banjo fittings and around the sandwich plate itself. I can almost 100% confirm it's not the banjo fittings but if anyone else has had issues with theirs, please advise if you can because the last thing I need is for my car to catch fire. Thank you

Mishimoto have a lifetime warranty for the majority, if not all, of their products. I would explain the situation as you have and request a full replacement. Whenever I’ve had issues in the past, I’ve just contacted them and they’ve sent me out replacement parts free of charge. Obviously if it is at the installers negligence, then it isn’t on them, but it sounds like you’ve just got a lemon; it happens.

Update the thread if you manage to sort it, I’m interested to see what the verdict is.

I'll give them a shout on Monday and see what they think. Will leave an update when possible, thank you!

I think mine leaks as well somewhat around the bottom of the seal on the sandwich plate but not enough where it drips. I guess ill contact them about an o ring replacement or something

Don't bother, got all replacements, full re-install and it still ended up leaking a tiny bit. It's unfortunately the nature of the beast, and some other sandwich plates do the same thing so pick your poison

Mine leaked a lot too. What I found worked best was to replace the gasket between the plate and the filter location (where normally the filter goes where you have no plate) annually at least, and to do not torque it down a lot, only a bit.

In my case, what happened was the oring which is normally a square (as in the shape that goes around the circle, if you were to cut it), but it gets squashed by the heat and just doest seal. So my solution would be to torque it down very little, and every time the leak started to appear, juste give it a bit more torque, and when it seemed it was all the way down, just replace it. Its just a normal oring, exactly like the one on your oil filters, so they are easy and cheap to find.

I just started wedging a strip of paper towel in the moat. There was a thing with my Mocal adapter which I heard but cannot confirm has been corrected. in my case, I shortened the female end of the extension so it wouldn't bottom out before adequately squeezing the seal.