What is wrong with my car?

Question

It's a 2000 Jeep GCherokee. There is a dial on the dash with a picture of an oil can and it says "0...40...80" but of course it does not state what it is, exactly, that those numbers are measuring. Anyhow, its been pointing at 80 lately, so I got the oil changed, but the dipsh*t didn't seem to have any idea WHY it might be pegging, but said that it's a pressure gauge.

So my problem is that it keeps showing high pressure, but if I go fast on the freeway for a while it points around 60 or so until I slow down or stop, then back to 80. What will I need to do to correct this, or will it correct itself with the fresh oil? And if its a pressure thing, wouldnt the pressure have released when they let out the oil? I'm not having any trouble with any other guages, and the car doesn't seem to be acting funny at all (knock on wood grained paneling...).

Answer 1

This is your oil pressure gage. Typically you won't have a problem with this going to high - its usually a problem with the oil pressure sender (sensor) or perhaps the display unit.

My money is on the oil pressure sender. Should be under $20 for the part, and should be a 20 minute or less job for a mechanic.

The oil is only under pressure when the car is running, between the pump and the little ports it squirts out of throughout your engine. I suppose it could go high if you were to only change the oil, and never the filter time after time. But most people change both, as recommended by most vehicle manufacturers.

Answer 2

It could be the sending unit for the oil pressure gage. 80 # is good pressure. The pressure always goes down a little as you drive because the oil gets hot and flows easier, needing less pressure to move it along. The pressure drops to 0 psi when engine is not running. The system is not a constant pressure unit. It only works while engine is running. Low or no pressure (under 10--15#) when running is what should concern you. Change the oil filter at least every second oil change.

Answer 3

That guage is an oil pressure gauge. The guy that changed your oil is probably not a technician, he just changes oil. Most stock guages do not read accurately. With a accurate guage, your pressure at idle will be low, probably around 20 p.s.i. At highway speed, probably 60 p.s.i. Generally, from idle up, it is 10 p.s.i. per 1000 rpm. At 1000 rpm, it is 20 p.s.i., 2000 rpm is is 30 p.s.i., etc. I'd guess and say that your oil pressure sending unit is bad. A service manual would be able to dignose the problem, with the proper tests. I have a guage that I can replace a sending unit with to check that actual pressure, but I'll assume you don't have one. Get a manual and follow it, you'll get it fixed.

Answer 4

It is, of course, the oil pressure gage that you are looking at. Go to your favorite parts store and get the oil sensor unit for your Jeep. Ask them to please show you where it goes in the engine, if they aren't busy they will. If you aren't sure, take it to your favorite mechanic, it's not a hard job. You unplug the wire, screw out the old one, screw in the new one and plug the wire back in. Bet you a dollar that will solve your problem.

Answer 5

Sounds like your oil sending unit is going bad. Easy fix, not terribly expensive

Answer 6

it's a pressure gague...the sending unit is clogged...try adding an oil cleansing additive next few oil changes...or replace the sending unit

Answer 7

0....40....80.....is P.S .I. means pounds per squared inches.
replace the sending unit.

Answer 8

oil presure gauge,clogged oil port might take it out and open it up might push through.