dr_ed

Interestingly enough I recently brought a Mitsi GSR which had done a head gasket, they also have a similar type thing attached to the back of the block. I fixed head gasket started it up and ended up having 2L of oil get pushed into the water in 5 min . After some logical thinking and testing turns out the "queer oil cooler thing" had a leak in the jacket between oil and water, going to change to air oil cooler to stop this stupid thing ever occurring again.

Is it a squeal or a whistle, If it is similar to SR20 could be cam lobe oiler's, its very common in earlier model SR20's (as said) and they squeal ( pull rocker / cam cover off and you can check if they are blocked or there is black oily gunk on / in them) The other Issue I had that I couldn't figure out was my car again SR20de would sometimes whistle / squeal while at idle (mostly when sitting in traffic when hot i.e. motorways etc), and sometimes only when you turn the engine off it would let off a small squeal / whistle sound, finally figured out that water pump was on its way out. (but I would presume that would have been done when belts were done) I know its not the same engine but could be possibly similar.