as i was having problems with my oil light that i posted in another thread, i hooked up an oil pressure guage today and here's what the reading were:
start up: oil pressure guage went up to about 50 psi

after motor was warmed up: pressure dropped to about 20psi

while the motor was warming up, we reved the motor and held the rpms at about 3k. the oil pressure went up to 100psi

went for a drive drove normal, the oil pressure rose to about 50psi or so. got on the gas and hit about 6lbs of boost, oil pressure rose to about 100psi.

came to a complete stop and and i was slowing down, the oil pressure started dropping. when i was at a complete stop, the oil pressure dropped to about 4-5psi.

on the way home driving normal, the pressure rose up to about 50psi, hit about 4lbs of boost and the pressure was about 75psi. as i was pulling into the shop, the pressure dropped again to about 4-5 psi. i parked the car and let it idle and the pressure stayed real low, below 10psi.

i'm thinking its the oil pump thats going out, what do you guys think?

 

It's very possible. Also, how's your oil feed and return line to the turbo? Any kinks in either of them?

 

no kinks in either of them. they are both fine.

 

Well, I know it's a PITA, but may disassemble oil pump and inspect.

Let us know if you find anything...

 

how do you know if the oil pump is bad?

what do you look for?

 

for scoring in the pump housing, scoring on the pump drive and driven rotor, broken pump rotor.

Had an H22a4 engine eat a stock oil pump into 5 pieces and tear up housing at 9200 rpm.

Installed new high performance pump (Prodrive is the only one that seemed to make one for H22a4, don't know about others) and have not had any oiling issues since.

 

Also, want to make sure oil pump pressure relief valve isn't sticking open. Have seen this a few times as well. this could definitely cause the low oil pressure also if stuck wide open.

It's a small piston with a spring behind it that can sometimes get debris hung up in it or lodge itself open in bore. Definitely make sure it works and moves freely from open to close.

 

anyone else?

 

Did it start doing this after your turbo install?

I really think it has something to do with the turbo - the lines may not be kinked, but the return line may be tapped into the wrong portion of the oil pan, or the pickup line may have a problem. Perhaps the turbo oil passageway is clogged?

Replacing the oil pump wouldn't hurt though...

 

i have everything the way i had it on my other motor. all i did was put a different motor in...nothing else.

so the oil pump on this motor that i just put in could be going out. i checke the feed line and its not clogged. the return line is fine also as i checked that before
i put it on the motor i just got.