We just rebuilt the engine a couple of days ago. The engine runs great and started up on the first try. The oil pressure read the normal idle at 35 and topped at about 65. Day 2, while cruising, the oil pressure suddenly dropped to 30psi at 3000 rpm. We tried 3 different gages and they all read the same. We pulled the sending unit out and turned it on and we have really good volume. We also bypassed the oil cooler in case of restriction, nothing. I can run it for a while and let it idle for 15 minutes and does not get any warmer. Any ideas.

 

when you rebuilt it, where u aware of the front cover oil control ring problem?

 

Yeah, sounds like front cover O ring squeezed out

 

I don't have any insight for this post, but I was just wondering what the oil control ring problem is. I am doing my first rebuild right now and I want to avoid this problem. Is this the problem where mazda provides an o-ring that is too big? Modification needed?

 

http://www.mazdatrix.com/FAQ/ORING.HTM

 

Not it. We pulled the oil pan and found a little piece of **** stuck in the oil return *****. It was holding open the plunger. Thanks for the input on the front plate. We will be building more in the future.

 

I stand corrected. We were puting the pan back on and saw that the oring was crushed and split. I pulled the front cover off and found the teflon oring and put it in with another oring in the center. Now I get great pressure. Thank you for all your support.