Hi Would anyone out there know what the specification for oil pressure should be in a running NA? At idle mine runs at 15 ft-in sq and Im not sure if that's ok or not because I've seen it higher before at like 30 ft-in sq.

 

Fully warmed up the idle psi should be approx 30psi. At 3000 rpm the psi should be 60psi..at least.

Most bad oil pressure readings are not caused by the sending unit but by a gauge that has been damaged in the past. If doubt exists as to the real pressure buy a simple and cheap SUNPRO from autozone or pepboys or???? and install it temp. You'll need an adapter to screw into the engine housing after you remove the stk sending unit. The threads in the housing are something like 1/8" BSP and can be bought ??? got me. Pegasus sells em online or pepboys or whoever. I can't explain anymore than that. I've yet to see a bad sending unit (barring someone monkeyfucking it to death).

That stuff is given honorable mention in the LUBRICATION section of the FREE AND ONLINE factoryservicemanual or FSM. One or the other.

 

Hailers, although you are correct, i have seen oil pressure much lower in other peoples cars as well as mine. i get around 10 psi fuel pressure at idle and then it shoots up to 30 whole cruising and 60 when i hammer the throttle.

 

the issues stated with your example usually are caused by an o-ring that has blown out from between the front cover and the front iron. this could also be the OP's issue as well.

a starting point is checking that the oil pressure is in fact low like Hailers suggested.

 

I'm 90% sure this is the issue I have, oil psi is like 10-15 @idle, but fine otherwise. There seems to be oil residue around the front iron, although it seems to be coming from between the iron and the housing.

 

This *oil residue* you mention. Does it originate up high on the left outboard side of the mating surface b/t the housing and front "iron"? Just about the area where the word MAZDA is embossed????

If it does...........that is the area where a dowel pin aligns the front "iron" with the rotor housing, and that dowel pin has a oring around it to prevent oil leakage. It's actually a passage for oil b/t the 'irons" and the housings.

The only way to stop that leak is .............rip the engine down and replace the oring(s).

The attached jpg shows the flow of oil in the engine. I used a red arrow to show the area of the oring mentioned and where they leak. That oil passage shown with the arrows showing flow direction............runs along the top of the housings and has a dowel pin with oring to prevent leakage at each mating surface of the housing to each other.

Make sense?

 

the leak i'm referring to is internal and not visible to diagnose. it requires removing the front cover to see if the o-ring is still in place. but as i said, before going through all the trouble i would double check the oil pressure with a mechanical gauge first.

 

And the oil leak/residue I mention is b/t the front side housing and the front face of the front rotor housing. Not talking about low oil pressure but where and what the *residue* is and where it comes from.

 

Son of a bitch!

Oh well, guess I'll just check my oil more often.