so I recently changed the intake manifold gasket and I changed the oil from the milky coffee to fresh oil but my oil pressure gauge doesn't move when I start the truck. It wont move at all. Could this be a gauge issue or an oil pump issue? The truck doesn't over heat anymore and seems to idle fine. i haven't drove it since the gasket replacement so do you guys think its fine or something to look into. Also after i was done with the replacement the battery was dead. I have had battery issues before so I didn't think anything of it.