TSIO 360 LB Low Oil Pressure

[John Darke]

1984 M20K with TSIO 360 engine.  Experiencing low oil pressure, especially when oil temperature is high.  Thought it may be the oil pressure relief valve so purchased new spring, plunger and gasket.  Discovered that the seat of the valve has some pitting and should be lapped.  Does anyone have any information on a tool that has been developed to lap the seat of the oil pressure relief valve?  Any information would be greatly appreciated.

[Guest]

Have you checked and confirmed that the oil pressure is low?

When our O-200 had low oil pressure, I bought an extra pressure cap and valve.  I cut the cap off so that it became a bushing/guide, screwed it into the case then used the valve with some lapping compound on the end to lap the seat for a better fit.

I’m sure there is a special tool to do this but this worked fine to improve the seat.

Clarence

[carusoam]

Welcome aboard, John.

Sounds like cleaning up the seat is the way to go... 

The higher OilT is just making the problem worse... viscosity drops as the oil gets hotter.

He is the mechanic, i’m Just a PP...

best regards,

-a-