Oil cooler leak help needed
 

Installed Z1's 25 row (thermostatic) oil cooler kit last weekend and thought all was well, but then found a slight leak when I went to double check it. Per Z1 (forgot the person's name), I retightened all the fittings - ended up having to take the oil filter and sandwich plate off then retighten. Unfortunately, it's still dripping from what appears to be the left side (Mocal name engraving). I felt around the top where the fittings are and i don't think it's leaking from there.

Can anyone suggest anything else to check? Is it possible that I'm still not tightening the fittings enough?

I would call Z1, but I don't think they'd be open tomorrow.

I had a failty sandwich plate housing with mine, bad casting, it was leaking through 2 tiny little holes in the casting but it was on the opposite side where yours is leaking. Try getting a small lighted inspection mirror in there to see where it is leaking from. Ended up replacing my plate with a new one. Good luck.

That looks like its either loose or to tight

Reinstall it and don't over tighten the fitting that bolts the plate to the block, And make sure both surfaces are clean.

I know its bloody mess!

I had the same issue once.

I just reinstalled and tightend just enough that it was snug and have not had any issues since.


edit: Never mind just saw you did that :(

I was feeling all around it with my hands and a clean rag.


The fitting that screws directly into the sandwich plate moves when i'm tightening the lines unto it...i guess i can use another wrench to hold the fitting in place so it doesn't overtighten.

The Mocal thermostatic plate comes with a large rubber seal and this is the ultimate sealing that you can get comparing to a tiny oring style. However, over tighten or under tighten the center bolt can lead to slight oil seepage.

I have done at least 6 oil Mocal plates installations. What I did was to be sure that both the block and the rubber seal surfaces are clean. Also make sure that the rubber seal surface is not damaged in anyway. Then lubricate the rubber seal's surface with a thin film of oil.

Finally, position and manually hold the plate where you would like the oil cooler lines to be at, torque the center bolt down to 36 ft-lb. You should never have any issues.

Now if the plate leaks somewhere else, then that would be a different issue. However, by judging your photo, the leak seemed to have come from the rubber seal gasket.

Good luck

Alright, so I took off the oil filter and mocal sandwich plate off again to wipe, lubricate, and make sure that the seal is not damaged and securely positioned. There is no wiggle room between the back of the mocal plate and the oil pan area. I had a friend hold the mocal plate in-place while i torqued the adapter bolt with a torque wrench. Z1 warned not to apply more than the ~25 ft/lbs of torque, but i did bump up the torque by a couple ft/lbs. Once i put the oil filter back on, i started the engine and it's still leaking from the same area...

I had a 2nd pair of eyes and hands on this - the leak is definitely not coming from the top or the bottom. What we believe is that there may be a small fracture/crack just immediately to the right of the mocal name engraving on the left side.

Gonna call Z1 tomorrow to have them send out a new mocal plate and hope to God that does it...

it appears to be where the piston slides in and out to control the flow. those are removable and you are able to put a different spring. most likely it was over torqued when assembled or under tightened. let us know what z1 says.

Also check to make sure you have the right size threaded fittings going into the sandwhich plate... they shouldn't be moving as you had previously mentioned... did you use any thread sealant? I used teflon liquid sealant (sparingly) on all the fittings.

I'm not quite sure what piston you're referring to; do you mean the hexagonal piece on the southern tip of the mocal plate?

I didn't use any sealant. The kit kinda comes somewhat preassembled - the fittings were already on the mocal plate with the washers. Following the instructions, you just tighten the fittings. Also, the leak isn't coming from the fittings. This picture was taken while the engine was off (with the leak occurring much slower) and looking at it again, I guess you can't really see the oil by the mocal name engraving - but this is where I think the leak is originating from.
I got an RMA from Z1 for the mocal plate so hopefully the new one does the trick and Z1 can find out what's wrong with the 1st one.

They're open today... give em a call. I'd like to know what the issue is before i purchase mine. :tup:

I see it on the thermostat itself and a bit on the seal...

Good luck with the replacement... I'd try a bit of sealant just to be safe... I think most people do.

yes inside the hexagonal piece is the brass plunger that controls the flow of oil through the cooler via the spring.

:iagree: That part is the actual "thermostat", hence why I referred to it is the end of the thermostat... without that part it is just a standard sandwich plate that is always fully open.

I know this is different than your scenario does the sandwich plate bolt not fully tighten the sandwich plate? For example on my 2012 it has a plate already for the stock cooler and I added an additional cooler, when I added the 2nd plate the bolt or whatever you call it was too long so it wouldn't tighten the plate tight enough. I had to grind down about 2-3mm to get it to tighten up.

I received a new mocal thermostatic sandwich plate adapter from Z1 and installed it over the weekend. It's definitely better than the previous one, but it still leaked a small amout of oil after ~100 miles of driving over the weekend. There was still that drop of oil hanging at the tip of the thermostat and a couple of dried up oil spots on the undertray. The 100 miles of driving included WOT pulls (as much as one can on the streets), highway cruising, and some moderate traffic (in northern VA terms).

I'm not sure where the leaked oil originated - is it possible that the oil is just leftover residue because i didn't do a through enough job of wiping down the plate after the install?

To help rule that out, I gave it a good wipe down this time so I'll just check it again after maybe a week or so.

On a positive note, the oil cooler kit works in keeping my oil temps ~20-30 degrees cooler.