my expy has oil pressure issues. When I start the engine cold, oil pressure is at its normal operating pressure as indicated by the gauge. After the engine warms up to normal operating temperature the pressure gauge will indicate at random a total loss of pressure. The pressure gauge will show pressure one minute then none at all the next and will toggle back and forth between a normal pressure reading and no pressure whatsoever. If the oil pressure stays off, the engine will start to run rough in about 15-30 seconds as all the oil is sitting in the pan and not being circulated.

I joinded alldata.com and see that the oil pump may have a pressure relief valve?? at this point my only guess is that the pressure relief is malfunctioning in some way causing oil to not be circulated as regular.

The local ford dealer was not able to diagnose the problem without an expensive engine tear down but they did rule out pressor sensor/sending unit as the problem. I want to simply (not so simple) replace the oil pump but want more info to support the idea that the oil pump replacement will solve the problem.

If anyone has any advise as to a reason behind the pressure problem it would be highly apprieciated by me and my expy. thank you for any time anyone may have.

 

Could be that the pick-up screen is clogged up. It may have other internal damage if driven much without oil pressure. I just had to replace a 4.6L that was driven 1/2 a block with no oil pressure because it ate up the head where the cam rides and gaulled up an intake valve.