On the 22re can anyone tell me what the small plate on the back side of the cylinder head is? Thanks

 

If you're talking about what I think you are............I believe it has something to do with coolant..I was wondering what that was too when I started taking my engine apart and that's what someone told me so..no experience here, just what I've heard.

 

Thanks, the reason I ask, I have coolant leaking from the back of the motor, the hoses that go into the firewall are good, but it leaks on top of the transmission where the motor and the transmission meet.....I am stumped!