Spiked 99 Oil pressure

Just in the past couple days I have noticed that my 99 cherokee is idling at about 40-50 and when I touch the gas AT ALL it spikes up to 75-80. I don't get it at all. It seems to run fine but it just scares the hell out of me to see the guage maxed at 80.

Any help?

If it is pegged out then it may have a open. Check your connection to it. If that doesn't help replace it. It is located next to the oil filter on the pass side of the engine.

Just to give you an idea of what it does, unplug it with the key in the run position and you should see your guage peg to max.

So that is my opinion when you hit the AT it vibrates and the connections faults and your guage pegs out.

when i had my 99, it did it for awhile then quit and went back to normal.

never could figure it out.

XJ Stryker said:

If it is pegged out then it may have a open. Check your connection to it. If that doesn't help replace it. It is located next to the oil filter on the pass side of the engine.

Just to give you an idea of what it does, unplug it with the key in the run position and you should see your guage peg to max.

So that is my opinion when you hit the AT it vibrates and the connections faults and your guage pegs out.

Click to expand...

The thing is that it doesn't just instantly go to 80. It just moves there. Its weird. Is 45 high for idle?

If it isn't the connector for it, (already mentioned) it's probably the oil pressure sending unit (also known as the oil pressure switch in some parts stores).

The sending unit is by far is responsible for the vast majority of unexplained oil pressure readings. If you're ambitious, you can temporarily hook up a mechanical oil pressure gauge (where the oil pressure sender sits) to confirm, but most guys just replace em. I think that will take care of your problem.

I have had best luck with purchasing these directly from Jeep (for best reliability/accuracy/mating with factory gauge). Good Luck!