2 replies to this topic

[kavesh]

Hi all

 

My 308 motor was rebuilt about 2000kms ago. Not really an issue but I am always nervous about the oil pressure when warm at idle, always dropped to less than 1 bar or 14psi. give it a rev and the pressure climbs up 3 bars or 43 psi always.

 

After my recent oil change, using 15w40 oil (oil is same as before), I decided to open up the oil pump, the gears are all in good condition. I decided to give the 2 halves a little wet paper to even out any uneven surfaces and bring the halves closer together without binding. (I am reusing the oil pump, its not new, probably original).

I also decided to add a little shim by the relief spring maybe 2 to 3mm.

 

Anyways now on cold idle I am getting 4 bars or 58psi oil pressure and when warm at idle it reading 2 bars or 29psi.

 

When cruising the oil pressure reads maybe 5 bars or 72psi, probably closer to 6 bars or 87 psi

 

Is this too much pressure? Should I consider removing the shim from the relief spring?

 

Or am I overt thinking things.

 

Appreciate the advice, thanks

[warrenm]

It's not too much pressure, Holden V8's are notorious for low pressure at idle. 

[axistr]

The rule of thumb used to be 10psi plus 10psi for every thousand RPM. High oil pressure costs HP and increases fuel consumption. You don't need big number pressures. I would remove the shims under the relief valve before you start blowing out gaskets or oil filters. I sometimes fitted a 0.5mm shim under the relief valve but 3mm would be way too much unless the spring is bugged.