Possible oil issues?

[HXSR]

Hello everyone, recently my SR has developed a tap in the head, which lead me to believe one of the lifters is going bad, along with the tap it seemed like it was running on 3 cylinders, and I had a loss in power. Made it home with the car and parked it to listen to it run, after it sat for a bit it would crank up no issues but once it ran for about 30 minutes of driving it would come back. About 4 months back I installed my Holset HX35 turbo I got a whine which sounded like power steering pump, turns out after removing the belt it was coming from the motor itself. Ran the car with no belts, definitely motor whine. I installed a little Sunpro oil pressure gauge to check the pressure, sits at 35 psi when first cranked and hangs theres, even running it up to 6000 rpm, no fluctuation lowers down to about 20-25 once running for about 20 minutes, and this is on a fresh filter and 10w40 oil. The whine is there while the motor is warming up, couple of quick revs once warm it goes away sometimes.

Now I am trying to diagnose this as a lifter issue or an oil pump issue. Thoughts anyone?

Thanks for the help everyone.

[Lobo240sx]

First do a compression test to see if it really is running on 3 cylinders. Since you unhooked all the belts the whining noise could be a failing oil pump. That oil pressure seems a bit low on cold start. You should be A LOT higher like 60-80psi. Then back to like 30-40psi once engine warms up to operating temp. SR's can be a b**** sometimes so take your time. The tapping could be because you aren't getting the proper oil to the head.

[HXSR]

Doing a compression test Monday, think a larger oil feed for the holset turbo could cause a loss in pressure like that?

[Lobo240sx]

Doing a compression test Monday, think a larger oil feed for the holset turbo could cause a loss in pressure like that?

It shouldn't be that much off with a bigger feed. Give us the numbers of each piston. Needs to be like 145 -155+ psi.

[homeslicej2]

You should definitely have more pressure than that on a cold start and with RPM increases. After you do the compression test, start the motor, take off the oil fill cap (watch out for oil spattering out) and look to see if the camshaft oil tube has a steady stream of oil running out onto the cam lobe. You can also pull the valve cover, disconnect fuel and ignition, turn the motor over several times and see if you have oil coming out of the cam oil tubes over all of the cam lobes. This will help you know if you have oil getting to the head.

[HXSR]

I'll check that out tomorrow too.