oil pressure dropped down low almost out of normal range. If I try to go on highway oil pressure drops to zero. thick oil makes pressure go down thin oil makes oil pressure go up . I think the pick up tube is clogged up. It takes about 30 sec. after I start the engine for the oil pressure to start to go up . when the Van is warmed up the pressure will be on the N in Normal. When you raise the RPMs the oil pressure go down.
My car has 320000 miles.
My car has a manual transmission.
Hi there. Typically when the oil pressure changes based on the type of oil you are using, it’s an issue with the pick-up itself. Quite often, the wrong sized or style of oil pump or a pick-up line that is too short / long, can cause inconsistent oil pressure. It’s also possible as you indicated that the oil pickup screen is clogged with sludge or debris (especially if the engine has not been rebuilt). It might be a good idea to have a professional mobile mechanic complete an oil pressure light inspection to help you pinpoint the source of the issue and recommend the right repairs.