joseph mitro

after rebuilding my engine the oil pressure has been consistently 3.5 bar above idle with Mobil 1 synthetic, 15W-50, and about 1.5 bar at idle with the engine hot. bearing clearances were fine when i built the lower end.

i'm suspicious that my oil pressure gauge is not reading correctly because i took off the gauge faces (and needles) a couple times and I think maybe i reinstalled the needle just slightly incorrectly.

is there another method of checking the oil pressure? another gauge i can plug in somewhere?

Jakerx

1.5 is a tad bit low, but i wouldn't be too worried. when you drop down below 2 and get close to 1 that is way too low to allow me to be comfortable. but then again it might have something to do with the 15w50 being the thicker oil. if it has been sticking at 1.5 and not fluctuating at warm idle below that then i think you should be fine. we need our oil guru to chime in!

M758

was this after track running or street driving?

joseph mitro

track/autocross or hard street driving

seb928s

Crank bolt torqued tight enough? Also what idle speed is it at? If it's a lower idle speed it would have lower pressure.

M758

Those pressures are what I saw using Mobil 1 15w50 on my 944-spec car.

I swapped to Amsoil 20w50 Series 2000 oil and got 1 bar more pressure both at RPM and at Idle.

GlenL

Has the top oil pressure moved? The pressure relief valve will open at 5bar. If you'r still getting 5 bar in highway driving, for example, then the sender is likely fine. It won't fail by measuring a mid-range value low without lowering the high end.

joseph mitro

the top oil pressure when the engine is cold is consistently 4 bar at engine speeds above idle.

the crank pulley bolt is tight. i've already checked. i may have to try the amsoil.

Jakerx

mitro-meister...i've switched over to 20w50. i like it a lot better than the 15w50.