Brand New Oil Pump = 70psi Idle Pressure????

[skid542]

So I finally got my car started today after having spent the last four weeks trying to just change the timing belt and wear items on the front of the block.

Yes, 4 weeks... two and a half weeks and three tries to get the right water pump with the third nipple for the oil cooler, a couple days because I had to helicoil an idler pulley bore (the guy who worked on my motor last should be taken out back and beaten!!!, fourth bore I've had to helicoil on this block), and several other small things that shouldn't have been a problem but were. It's been getting way out of hand for something that should have been a simple day long project.


B**ching aside, now that I have it all back together I started it up and I have 70 psi of oil pressure at idle, at 160 deg. F coolant temp, and around 85psi cold. *Note my idle is around 1,100-1,200 rpm.

The pressure bounces between 70 psi and 75psi a lot even though the idle is bouncing around by around 100 rpm. This also seems odd.

Brand spanking new pump, OEM, purchased from 1stSubaruParts. It's the stock 22T pump.

I didn't do anything to the pump other than open the plastic packaging, clean the mating surfaces, and install it with new aneorobic sealant and firmly snugging the bolts (I don't have a torque wrench that goes low enough).


So my question - how big of a problem is having pressure that high? Seems way wrong to me as the old pump would do around 30 psi at idle.

Was there something I was supposed to do to the pump before installation? Seems to me that if I buy a pump from Subaru it should be all set and ready to go.

Is it just 'breaking in' and the pressures will drop after a little use?

I know there is supposed to be a relief valve at 85psi but if it's producing 70psi at 1,200 rpm, can the relief valve bypass enough volume at higher RPM's to keep the pressure down and not blow all my seals?

Any issues with my turbo seeing this much pressure?

I have a hard time thinking that I would have gotten dirt into things and plugged up a bunch of galleys. The car sat for a couple weeks with the oil pump removed but I had paper towels stuck in the opening to keep things out and the car slept in a closed garage where I wasn't really doing any other work.


Thoughts, comments? I'm afraid to drive it if this going to be a big problem but maybe this is normal for a new pump, idk, first time I've had a brand new pump.

Many thanks for all the help in advance.

[93forestpearl]

Where are you sourcing your oil pressure from?

My previous setup sourced pressure for the gauge from the turbo oil feed. With the .035" restrictor for the Garrett, I would have 85psi cold at 1500 rpm.

How long was the engine at operating temp? It takes the oil twice and long to heat up, even with the heat exchanger.

[skid542]

Well last night I spent some time on Nasioc and came to the conclusion the high pressures are fairly typical. I guess I need to come to terms with my hypocondriac condition and my car .


But, thank you for the reply Dan. I was hoping your expertise would chime in. I'm not totally comfortable with the issue yet.

I'm pulling the pressure from the rear galley plug on the top passenger side of the block.

The engine never got to full operating temp. I got sufficiently freaked out (I know...) and killed it once it got to 160 deg. so I'm sure that's part of the problem.

I did go ahead and drive it up to Sandpoint this morning, 45mi, and after everything warmed up the pressure at 1200rpm dropped to around 55psi - floats a little.

Going out for lunch I went ahead and did a couple pulls and you could tell the oil was warmer and the pressure dropped accordingly. I didn't see the pressure during the pull and it's not one of the values I'm logging so I can't comment on what it is at higher rpms. However, once the rpm drops the pressure goes back to 50-60psi and is around 70psi at cruise ~2,500 rpm.


I did notice a couple drops of oil when I got to work this morning coming off the little 90 deg. water fitting from the pump to the oil cooler hard line but I'm not sure where that is coming from. At lunch it looked only another couple drops had occured over the 4 hours. So I'll pull one of the timing covers tonight and throw an inspection mirror in there and see if it's coming from behind the timing cover or if it's coming from somewhere else.

One thing I think I really need to do now is verify that the previous owner has put a restrictor on the turbo feed line. It's an AVO 320 which has the garret ball bearing center section. I hadn't had any issues with excess oil in my intake tract before but now that my oil pump is doing what it should I feel that I need to verify this before I do any damage to my favorite turbo.


Again, thanks for the help Dan and let me know your thoughts now that I have a little more information for you.


P.S. - AWD_Addict - if you see this - I haven't forgotten you man! My garage is now finally clean and available and the weather's good. It'll be a good memorial day for carbon fiber work .

[Legacy777]

I'm curious what my oil pressures will be like once I get it running. I'll be teeing into the stock location for oil pressure info.