When I first st the car up the pressure is fine. But as soon as the motor comes up to temperature it drops to 20-25psi lower than it should be. At 3000rpm and up it doesn't get any higher than 30psi. If I rev hard it'll go up but then soon drop back down.

Any suggestions?

 

http://mazdatrix.com/faq/oring.htm
Was the engine recently rebuilt? Because it sounds like it was and the builder used the wrong front cover o-ring stuff like in that link. I would get an aftermarket gauge just to be sure, though, since the stock one can be unreliable.

 

As far as I know the block hasn't been rebuilt. It's got about 90xxx miles on it.

I was wondering if one the relief vales were going bad. Or is it possible that the return from the turbo is too freeflowing?

 

Are you verifying this with an aftermarket gauge? The stock sender likes to fail and how odd readings.

It's not due to anything related to the turbo.

 

What the guy above said about the mechanical oil pressure gauge to check to see what the real pressure is..