Oil pressure jumping all over the place

[mikevar94]

Please don't tell me that this thread is a repeat because I've looked and guess what..I can't get an answer for my situation. Anyway so this is whats going on, my stock oil pressure gauge was not working for a long time. The needle just sat below L. The other night I was changing my alternator when I thought I saw the oil pressure sender unit (because I read it was somewhere in that area?) so I figured I'd wiggle a couple wires and connections coming off it just to see the problem was a loose connection or something. So sure enough it works. The oil pressure gauge is now moving. Only problem is its everywhere. Mostly way above H. But randomly it'll come down toward the middle and maybe go down lower then jump back up. I don't get it. My question is, could it be a bad sender? Or maybe the gauge is bad? I really hope it's not accurate and my oil pressure isnt actually changing constantly...oh and also I read that if the oil light isn't on then your pressure is fine. Any thoughts?

 

[Breezio69]

Probably a bad ground connection or connection in general considering a wiggle to the wires is what made it work. I'd personally get an aftermarket gauge and replace the whole sender/wiring. The stock gauge doesn't tell you squat anyways...

For example, if the gauge were working and running on the middle line... what psi is that? What psi is the L... what psi is the H?..

Get it?

 

[Dsmkauai]

Well since you changed the alternator and you oil sender is right there along with the wire for it being tied into the alternators wires. I'm betting your wire is barely on or has a short in it and since the oil pressure sending unit is right there on the oil filter housing pretty much below the alternator, you moving the wires got it some sort of connection again. Check the wire on the sending unit which should be attached on the very end of it. The sending unit looks like a mushroom or hat and is I think the only thing with a wire on it on the ofh. Hope that helps let us know. And yes as long as the oil warning light works correctly, if it is off your oil level is fine. The gauge isn't really accurate and doesn't serve much purpose but to show you, you have pressure and if its higher or lower.

 

[dsmcurse]

There is no ground wire. The body of the unit screwing into the metal engine is the ground, the sensors only have signal and that's it, there is 2 sensors down there, a big one (which is the one that talks to the gauge that your lookin at) and a smaller sensor (this one talks to the dumby light lil red check engine style light in your dash) the wires do go along with alt wires and powersteering pump/RPM pick up wire, these wire suffer from its portion of the loomed harness going to hell from all the turbo hotness. All those wires get cooked over time from being near the O2sensor housing.

Peel back the brittle 20year old factory plastic wire loom and investigate all these wire for breakage. The wire that goes onto the big oil pressure sending unit is the wire your askin about, it slides onto the sensor spade style and the sending unit its self has a baby tiny lil peg that the plastic head of the wire slides onto. This connection peice also goes to hell with time. Gotta remember, these are just car parts, don't last forever

 

[Dsmkauai]

Ya I remember mine doing the same thing. The plastic connector broke abit and wouldn't always stay on or get good connection. I finally cleaned it really good made sure there was good contact and taped it onto the sending unit really good, no problems since. ^^ and yes there is the pressure sending unit and the low level/pressure dummy light, both connected right there next to eachother on the ofh.

 

[mikevar94]

Okay cool thanks guys. I was just worried this was a sign of bad oil pressure or something but it just sounds like the sender has a bad connection

 

[GRAVEDIGGER]

Do yourself a favor and just get one of these.

http://www.summitracing.com/parts/atm-4427

You get a new sender, new (accurate) gauge, and best of all... peace of mind