tranzow

Oil pressure gauge bouncing around, and sticking high to low. Oil level is properly filled. Just changed oil pressure switch and having same problem. Any ideas of cause?

Carlo_Carrera

Try cleaning the electrical connectors on the oil pressure sensor and check the connections.

tranzow

Tried that 1st than went with the sensor switch with no luck. Maybe bad oil pressure gauge?

Carlo_Carrera

Probably not the gauge. More likely a wiring/continuity problem somewhere. Maybe check the ground strap? It is on the lower right side of the engine.

"02996ttx50

you need a new oil pressure gauge sender unit. this is not new. cheap part.

Kevinmacd

He did, I guess the new one could be bad

s65e90

It's the spade connection most likely. I've replaced a sensor before and still had an issue and it was fixed by thoroughly cleaning the contacts on the car side harness. Also make sure it's a tight fit. It's a simple spade connector and if not real tight will cause your issue. Some finessing the connector with a pliers to make it snug may be required.

"02996ttx50

whoops. good catch. gotta be the connection then, no? what's left!

Kevinmacd

The oil pressure sender has two functions, one to relay actual oil pressure to the guage, the other half is make break switch to turn on the warning light if oil pressure drops below a preset limit!
The guage side also turns on a warning message in the guage cluster!

mffarrell

So, if you get the message oil measurement failure, but no oil pressure light, the part that measures oil pressure to the gauge cluster probably has failed?

Kevinmacd

Thats correct. Usually when you get that message the gauge usually shows "0". If the sender is intermittent, your gauge goes to "0" with the message then when the gauge restores the message goes off. If the oil pressure light has not lit, its usually the sendor side for the gauge, if the light the message and gauge reads "0" or low pressure you better shutdown,you lost oil pressure.
According to the schematic, one terminal on the sender is for the gauge the other is for the light.

jpflip

My experience with oil pressure sensor, look at the wires in the engine compartment for chafing and be sure both connectors are not touching anything after you raise the engine, if you lower it to get better access.....Before replacing the sensor one more time (yes it can be at fault again...) there are some other possible avenues to look at. Between the sensor itself and the cluster you have a total of three plugs. Of course one is located on the cluster itself. The second one X59/2 is in the engine compartment right side (25 pins)(Blue on pictures) and a third one X2/3 is in the passenger compartment (Green on pictures)... I never heard of a problem, with those plugs but our cars are getting old and moisture can become a factor.... Good luck and keep us inform of your findings....

jpflip

Agree with Kevin!!!!

s65e90

Yes, it sounds like you're making it bigger than it seems. It's one sender serving 2 purposes in that regard. If the connectors bad the gauge needle will not only be erratic but lose contact and throw the dummy light as no pressure and trip the dash light. It's all the same sender though.

993GT

connectors on the sender unit or faulty sender