oil pressure drops completely.

Have the oil pressure TESTED with a test gauge to find out the actual pressure after engine is at operating temp. ...Got to know that first! Then go from there!!... What's the mileage on the van?... How many miles on it?

when have you last changed your oil and filter ,filter may be blocked causing the bypass valve to open thus saving your engine also have you got the right grade of engine oil for the climate your in you may need to go heavier also make sure you have the level correct as going up hills really alters the level .if you have doubts try screwing another oil pressure gauge into the block and see what you get ,how many miles has the van done ?thin oil is good for cold climates 5w30 but you may need to go 20w50 do the easy stuff first new oil and filter but the right grade will tell you in the manual if you have one its the only stuff that you should really get right,I take it this is engine and not trans,if trans then it could still be the filter in trans sump and the wrong oil.regards