I have a '75 pickup w 20R engine that I rebuilt with an engnbldr rebuild kit awhile back. Every since the rebuild I've had crazy high oil pressure - it pegs the gauge (goes up to 120psi) when I rev lightly if the engine is cold and if I go above a couple thousand RPM with a cold engine it will blow the seal on the oil filter. Once the oil warms up it runs high (40-80psi) but runs with no problems. I've been running like this for quite a while but I finally have time to deal with it. Seems like the first step is to pull the oil pump and look for some kind of blockage on the relief valve but if it's not something obvious is there anything else that might cause this? The oil pump was new with the rebuild kit. No oil gauge before the rebuild so I don't know what the pressure was before.

 

I know on VW air cooled motors that have the external oil filter added, they will blow the oil filter if reved to high when cold. They bypass the oil pressure relief valve, so I'd look at that on your Toyota. Either the oil pressure relief valve is sticking, or the oil pump spring is to stiff. The first thing I'd look at would be the oil pressure relief valve.