2000 Plymouth Voyager

Engine Cooling problem
2000 Plymouth Voyager 6 cyl Front Wheel Drive Automatic 111000 miles

My oil pressure light comes on at low RPM. I checked the oil level and it was fine. I can put the van in neutral when stopped and rev the engine to cause the light to go out. On the interstate (at high RPM) the light stays off. There are no knocking or unusual engine noises. Also, wondering if I can check the pressure at the sending unit port at idle? What would be normal indications?

Thank you.
July 24, 2010.

When you do check it with a mechanical gauge the readings should 8-12psi at idle speed increasing the speed to 2K rpm should be within 40-70psi. Sounds more like the oil pressure switch is out of calibration

Jul 24, 2010.
I have a similar problem but on a 3.0L engine. It is 10 degrees Fahrenheit and would like to replace the pressure switch quickly. Does anyone know the location of the switch? Can it be done on the ground?

PS. I tried STP as a quick fix but as the oil warmed up, the oil light came on again. Yes, I changed the oil and filter (10w40).

Dec 10, 2010.