oil pressure

[shauno]

i have a2004 4.3 with only 65 hrs showing. after about 25 mins. @crusing speed oil pressure slowly drops from around 35 lbs. all the way to 0. engine still runs fine during this time.could it be? sending unit .gauge.oilpump.bearings? any help would be great!

 

[Docksidemarineservices]

Get a mechanical gauge remove the oil sender install the gauge and retest the engine. Your local auto parts store should have a test gauge.

 

[cforcht]

I has a similar problem this last weekend. oil pressure was good at idle. then when you got to around 3k it would jump around and then finally go to zero. I did as dockside suggested. I put in a mech gauge and tested it. gauge read 50 psi at idle. checked the sender with a multimeter and it was reading pretty much full ground when the engine was off. replaced sender and all is well. I actually mounted the mech gauge near the engine permanently as a safe guard for the future.