97 Ford F150 4.2L. While driving the oil prsseure gauge will drop and the oil light comes on. It goes back up on its on and the light goes off. Any suggestions of what the problem might be. I was told possibly oil pump or pressure switch.

SOURCE: Check Gauge light going on and off

One of 3 things can cause this behavior of the oil pressure light going on and off: (1) oil level might be a little low... double check and make sure your oil is porperly topped off; (2) sensor is defective... which might require replacement; (3) oil pump problem... this can be an obstruction of some kind of the oil pump. If there is a strainer, which is typical, there might be sludge or something else obstructing the entry to the oil pump, thus, resulting in lower pressure output. It is rare, not impossible, for the oil pump itself to be defective... but again, very rare. If the issue is at the oil pump, it willmost commonly be an obstruction. Try having the engine flushed professionally. There are auto service centers with this capability. It is probably the most affordable first step to take. If after a flush the problem persists, then have the sensor checked.

Johnny Massengill

• 345 Answers
• Posted on Nov 10, 2008

SOURCE: OIL PRESSURE LIGHT COMES ON AND PRESSURE GOES TO 0 ON GAUGE

Any time the oil pressure is 0 you take a chance of locking up the motor. The only way to know for sure is to put a pressure gauge in the oil pressure sending unit port on the engine and see what the pressure really is. At that point you will either have the peace of mind in the knowledge that the sending unit is really bad and needs replacement or you can then contact a repair shop and tell them what your testing has revealed. I wouldn't drive or run your truck while the oil pressure is at zero.

Good luck

SOURCE: Come to stop 99 Ram oil pressure drops to 0 check gauges light.

Change the oil! The 318Cu in V8 (5.2 liter) engine has a problem with sludge build up on the oil pump pickup tube screen. This engine requires oil changes at or before 3500 miles with a high detergent oil.