arnie_omagh

i have just bought a sti impreza and was wondering wat is the normal oil pressure on the gauge when ur driving and at what pressure suld become alarmed?

Cheers arnie

MaDaSS

Depends upon what grade oil you have in as well.
My 03 WRX has Silkolene Pro R 15w50 in it.
6 bar during driving; 3 bar or just over 3 bar on tickover when warm.
Others have reported 2 bar on tickover with thinner oil than i use.
For me, anything lower than 2 bar would panic me (as i have never seen this) and my Defi alarm is set to just over 2 bar.

MaDaSS

But i still love this saying i heard off here, "good pressure does not necessarily mean good flow!"

arnie_omagh

Thanks mate, and what about the other end, if it was up at 8 9 is that alarmingly high?

MaDaSS

The most I see is 7 bar on a cold start. It's never been higher than that.

his-n-her-scoobs

iTrader: (5)

The quote is correct. If you tried to pump tar round the engine you would have good pressure but little it any flow. That's why modern oils are multigrade, so they are not too thick cold OR hot, providing the correct grades are used.

If one of the galleries (or the filter/modine) was blocked then high pressure would also result.

Either way the pressure relief valve in the pump should open to dump oil back to sump (with it the flow). Think it opens at 6 bar but cannot remember off the top of my head but someone like splitpin or DavidAPI will know for sure.



Arnie, that sounds a bit high (over 100psi) I would check the accuracy of the gauge, the grade of the oil being used and lastly the pressure relief valve itself, they are known to stick open so they can probably stick shut too. If all ok then suspect an internal blockage.

Oh, and check the oil filter doesn't look like a balloon from the excess pressure, they have been known to burst if the relief valve is stuck. Not heard of it on an Impreza....yet.

STI Mav

According to my PSI3 monitor, my STI starts with an oil pressure of 6.7 bar and more often then not stays at around this level. On ocassions I've seen it drop to 6.5 bar or even as low as 6.1 but more often then not it just holds at 6.7 bar.

his-n-her-scoobs

iTrader: (5)

Cheers STI Mav.

Your and Madass's readings indicate that the opening pressure is around 6 bar, so I would think that 9 Bar (50% higher) would indicate something is wrong.

Hope it's just ludicrously thick oil.