oil pressure gauge maxed out
 

when i went to work today i noticed the oil pressure gauge was horizontal, pointing directly to the right. when i shut the truck off it stayed there so i tapped on it with my finger. it slowly moved down to about 60 psi, i turned the key back on(motor not running) and it maxed out again. i did just put new intake gaskets and a new thermostat in it but i don't think that that has anything to do with my oil gauge problem. any ideas?

thanks

mike

the truck is a '95' by the way

mike