Oil filter housing- oil cooler flow direction

[Wergen7]

Greetings. I'm in the midst of many things including installations of an aftermarket oil cooler. I plan to put a check valve in the line to avoid draining the lines while the engine is off and thus introducing air to the system every. single. warm up. Can't seem to find any information on which port is inlet/ outlet to/ from the oil cooler on cars equipped width oil filter housings with oil cooler inlet/ outlets. Still with me? If not, please go watch porn instead.

I understand there is a thermostat in the oil filter housing that restricts and allows flow to the cooler once the oil reaches a certain temperature (a temperature which I'm not certain)

Based on the looks, it looks like oil flows to the cooler from the forward port (where it appears the thermostat is located) and returns to the rearward port.

Yup, this is a post based on being too lazy to take the thing off and look at the gizzards. But also at the fact that this information seems exceedingly difficult to find.

I'd like to know for sure so I don't put the check valve in backwards and restrict oil flow to zero when at (unknown) temperature and cause..let's say...issues.

Cheers

[varg]

You don't have to take it off to know which side is the feed. Take a spirited drive and shoot the cooler end tanks with an IR thermometer, the side with the lower temperature is the return. Any check valve would be on the feed side. This is what the internals look like.