So my 12a starts up fine and runs and decent but while it warms up, the oil pressure disappears. I noticed there is a puddle to the left of the "MAZDA 12A" on the rear housing. Is this a dowel pin oil leak (between the rear housing and rear iron) or is there something else i should check out before pulling the motor for the third time this summer.

 

oil control rings are shot?

 

Better not be, its a fresh rebuild

 

That is a common spot for dowel leaks, yes.

Also, check your beehive.

 

You'd have to be hemmoraging oil in a fountain to lose enough from an external leak to completely drop oil pressure. Sounds like two unrealted issues to me; small dowel-pin leak, and something else bypassing/blocking pressure or foaming the oil so much it won't compress - - or a faulty sender that doesn't like the heat.

 

Any idea as to what it could be? I checked the beehive, didn't see any leaks

 

Are you running off the stock gauge? Those are very inaccurate from what I hear.

So does it show pressure when you first start it? When was the last time it was changed? What oil filter do you run?

 

It shows normal pressure at start up and the warmer the motor gets the less oil pressure shows until its fully warm, leaking the most, and with no pressure. The oil filter is the atkins one that came with the master kit.

Do you think there could just be a blockage in the dowel pin line?