Yesterday when I started my Jeep, I noticed that the oil gauge was on 80 - I swiched it off and then restarted it - this time it was between 40 and 50 - is that normal? and is it dangerous if it goes to 80 ?

 

what year? some of the old ones used a differnt system then the new crap.

 

2001

 

Oil gauges are commonly out of whack on XJs. Replacing the sensor is a good place to start.

 

which sensor?

 

Oil pressure switch...right above the oil filter.

 

thanks, but is it dangerous if it reaches 80 ?

 

Not sure on that one. Your sensor might be on its way out. If I were you, I would plug in a mechanical gauge in its place to verify pressure.

 

High oil pressure is a bad thing. When it gets to high, the oil will not lube anything because it is shooting right over it is that needs the lubrication, such as your rockers. I had the same issue right before I started lossing oil pressure, I eventually had to replace my oil pump. I would get a mechanical gauge and hook it up where your oil pressure sending unit is and verify that your electric guage in your instrument cluster is reading correctly. If the electric gauge is not registering correctly then replace the oil pressure sending unit. And if that doesn't work, I would remove the oil pan and take a look at your oil pump and see if the screen for the oil pump pick up is clogged with sludge or any type of foreign matter.

 

A common failure on the oil pressure guage is the sending unit (above the oil filter) where a break in the wire will cause intermittent contact. When this happens the guage gives a false HIGH reading. Or the sensor just fails. It's unlikely you are really seeng 80PSI OP. Check the wires or change the OP sending unit if bad. About $20.

 

^x2 on that . . . if your oil pump is actually shot you should start to hear a lot of noise under the hood - rattling, whining, etc. And your engine temp might read higher than normal due to poor lubrication.

Start with the cheap and likely fix then work your way up unless you see other symptoms of a bad pump.

 

I had an oil pump go on me in a Toyota once. You would definitely know that something is terribly wrong if thats what it was. Im talking about lurching and knocking, just overall awfulness...

Like everyone else said, probably your sensor.

 

thanks to all!
I have no noise till now!!!

What about cleaning the electrical sensor - wires - electrical contactors ....?

 

X2 in my xj, I have a problem where the needle is actually off the charts (towards the high side) I changed out the oil pressure sending unit but the weather got cold on me and never got a chance to look into it further. How can I check the wires and what not. (sorry for sealing your thread!)

 

What kind of noise? Did you change your sensor? As far as I know it should just be replaced, not cleaned or fixed (somebody please correct me if I'm wrong on this!). A mechanical sensor will give an accurate reading versus the electrical one that comes stock.

I read another thread about oil pressure and it was suggested that bearings may be the culprit of some noise. Check it out: https://www.cherokeeforum.com/f2/oil-pressure-drops-jeep-warms-up-72667/