Lately, we've been getting a low oil pressure warning (idiot light) on the instrument cluster and, every so often, an actual audible alarm indicating the same. We check the oil before every engine start -- the viscosity is good and the oil level is stable. The machine also seems to be running normally, which leads me to believe that we may have a faulty oil pressure sensor. The machine in question is a 2002 CAT 420D (FDPXXXXX) with a 3054 Engine. If anyone has any experience with testing the oil pressure in this particular engine -- or changing the sensor in question -- I'd appreciate any advice I can get on the subject. Thanks for your time
Not with that machine, but the old diaphragm style pressure senders would get a pinhole and read normal pressure for a while then the pressure would ominously drop to nothing as the pressure equalized on both sides of the diaphragm. Shut it off for a while and you had oil pressure again, the only way to test that is to tee in another gauge and verify the actual oil pressure cold and hot. The other thing to check is the wiring, if grounding the sensor wire gives you high oil pressure, then losing the connection will give you no oil pressure (readings of course).
I'm with Delmer. If the wire coating is not flexible, there is a chance the wire is defective. Check the ends too.