Hi all. I seem to be having some issues with my oil pressure. I recently degreased the engine compartment and had a very clean motor sitting there. As of late i have noticed that there is oil covering the valve cover again and seems to be coming out from the oil fill cap and the two lines going to the manifold and air filter housing. I did also notice that the air filter element had some oil on it to. Just wondering what may be causing this. Oil has about 1500 miles on it and i did notice it was about a half quart low this morning. Any thoughts from the XJ Gods??

 

here is a pic of driving in passing gear and the oil pressure gauge was pinned.

 

More then likely your oil pressure sending unit is on it's way out. But if you want you can always verify the pressure with a mechanical pressure gauge.

 

I can agree on the sensor possibly going out. But what about the oil coming out of the top of the valve cover? How do I stop that from coming out or is that an indication of there really being to much pressure?

 

Try a new valve cover cap yet ?

 

Get the factory one those cheap ones never seal real good....http://teamcherokee.com/engine-oil-f...che-1991-1995/

 

I will order one up and hope that stops the seeping out of the top. How do I check the pressure mechanically?

 

You can rent a pressure gauge at almost any parts store. Remove the oil sending unit and screw the gauge in where the sending unit goes. Just be careful when removing the sending unit they are pretty fragile and if it is reading right and you hit it to hard that alone can damage it.
BTW, Minimum pressure for the 4.0 is 13psi at normal operating temp at idle.

 

Mine reads kind of high, but I think it's just the sending unit. Mine reads like this:

Not warmed up at idle is around 45-50
Warmed up at idle is around 30-35

Not warmed up while driving is around 50-55
Warmed up while driving is around 40-45

Before these elevated readings, I was on a trip across country from California to South Carolina and the needle pegged past 80. I pulled over to make sure there wasn't something catastrophic going on. It didn't stay on 80 for long, though. Gauge readings have been elevated ever since. It's been almost exactly 3 years since that trip (left California on 2/14/11).