I have a 97 pontiac bonneville. when i start the engine up the oil pressure’s fine util it gets warmed up then the needle drops. It doesnt go all the way into the red it just fluctuates right over it at idle. Would replacing the pcv valve and putting a thicker grade oil do anygood? Or could it be the oil pressure switch malfunctioning?
And yes i checked the oil level its completley FULL!