Hello, sorry my first post is asking for help but I tend to lurk and read more then post. I have tried searching but never seem to come up with any answers. Anyways, I'm having an oil pressure issue on my '91 NA6. Its got 168k or so on it. Currently I'm not seeing any oil pressure over ~35psi at any rpm range once the engine is warmed up.

Back story, engine started pucking oil out of the front seal and others back in April. I pulled the motor, replaced all seals/gaskets but head gasket and valve seals. Ran perfect, went to an autox and after my 8th run I noticed my oil pressure was low,

 

If it had bad leaks, it was likely run low on oil, which will wear out bearings very quickly, increasing their clearances, and that will reduce your oil pressure.

What weight and type of oil do you run? If conventional 10W-30, considering going to a 10W-40 for more oil pressure.

 

I noticed smoke behind me when it was peaking oi . Pulled off the highway and had it towed home. Checked oil once home and it was only a quart low. I checked all bearing clearances and replaced with new bearings, all within spec. I ran 10w30 Mobil 1 before I replaced the pump and bearings. I then ran valvoline max life 5w30 after replacement and just tried Orielly house brand 10w40 full syn oil.

 

Hmm. Well I dunno. I have a friend that changed his oil pump and only had about 30 PSI oil pressure afterwards too. I wondered if he left off the o-ring on the oil-pump where it bolts to the block. Seems like if it was gone, pressure would be almost nothing though but I dunno. Are you sure you installed that O-ring? What brand pump did you use?

 

The na6 doesn't use that oring from what I recall. The new pump is a reman ITM pump. I do not remember that oring recess when I put the pump back on but knowing the factory pump doesn't use that oring I might have not paid too much attention to it. New gasket used was for an na6. Wouldn't I see oil leaking from that area if the oring was missing?

 

If you used a gasket, there's no o-ring. The NA6 pump is different.