I have a 1979 toyota pickup 4x4 I just recently bought the truck from a buddy of mine it has the 20r engine in it, every time I start it on a cold start the truck seems to over pressurized the engine and it blows the seal on the oil filter and I found that the relase value in the oil pump was stuck from the over pressurizeing of the engine so I cleaned it out and it seemed to fix the problem until I started it and it did it again is there anything I can do to stop the engine from over pressurizing.