So I have a 2001 jeep Cherokee and I have developed a new issue. when i am driving my oil pressure gauge is reading right around 40 (normal pressure) but when I stop my oil pressure drops to 0 and my check gauge light comes on. does anyone know why it does this or if there is a way to fix it?

 

I would possibly try your oil pressure switch. They run about $33.

 

If your running a fram oil filter it can cause problems like that.

 

Checking your oil pressure with a mechanical gauge to verify a problem is even cheaper than guessing and throw parts at it.

 

i agree, get the tester, you might be able to ever rent it from a store for a day or 2, it could be a bad filter (fram), the pump is bad, or the pressure bypass is defective.

 

thanks for all the responses. what is the specific name for the mechanical gauge, Advance or Auto zone probably has a mechanical gauge. i do not have a fram oil filter in it because i do not like fram. once again thanks for all the recommendations.

 

Exact same thing happened to my 98 and my buddy's 99 and that's what it took to fix it. That's why I suggested it.

 

for the tester or the replacement gauge? the tester is just an oil pressure test kit, or you can just look up a cherokee oil pressure gauge for the replacement.

 

Go to hardware store and buy a well pump pressure gauge for around $10. It needs to have threads of 1/8-NPT. Unscrew sensor and screw in gauge....it is that simple!

 

How would you check it under actual driving conditions?
Anyone ever try the tester kit from Harbor freight?

 

You don't need to check pressure under actual driving conditions. You can get accurate enough oil pressure numbers in your driveway to make a diagnosis.

If your pressure is truly dropping dangerously low as is now indicated on your dash gauge, the mechanical oil pressure test will either confirm or deny that. Get some numbers and you can go from there.

The oil pressure spec for the 4.0 is this:

*Not less than 13 psi at HOT idle
*Between 37-75 psi over 1600 rpms

Good luck and keep us updated on what you find!

 

thanks i will probably buy one and put it on there. thanks

 

I might try to buy a kit from harbor freight and test it. thanks for all the answers