i have no reason why it did this. i tapped into the head and the gauge reads 80 psi and after i let it sit for a minute it goes to 75psi and stays there. oil is right where its supposed to be, the gauge is mechanical, and everything is how its supposed to be. i think theres a kink somewhere in the line but ive already checked for that. its supposed to be at 40 psi at 1500rpms hot. ne one have an idea.