I know its 13 psi for 5w30 but what is it for 10w30? I'm showing 40 for idle.

 

5W30 and 10W30 are the same vis at operating temp so pressure should be the same in the same motor and same operating temp (100C).

 

My engine is spotless. No sludge what so ever. So nothing should be clogging up the oil pick up tube. I just swapped from 5w30 conventional to 10w30 blend.

 

Too many variables to predict oil pressure. 2001 & 2000 4.0 engines are known for low oil pressure sometimes attributed to the head cracking and sometimes cam bearings were goofed up at factory and occasionally for no explanation. Oil pressure is a indicator NOT a function. As long as you have adequate flow to keep things lubricated your good to go. Pressure does not contribute to longevity if it is low you have other problems (excessive clearances) , not oil pressure problems.

 

Mis-read your post. Is that 40psi at cold idle or hot idle?

 

Hot idle.

 

Mine is 40 at hot idle and 60 while driving according to the oil pressure gauge inside the dash.

 

40 at hot idle is totally normal. Not that the in-dash gauge is worth much lol. Generally above the middle mark when cold and below the middle mark when hot is normal. Important thing is that its not through the roof, you build pressure with engine speed, it's not 0, and your engine isn't making noise. Sudden changes should be investigated. If you're concerned then use a mechanical gauge to test.

Also 5w30 and 10w30 are both 30s at 100C - no idea why people think otherwise.

 

.....and 0W30 along with straight 30 are 30 at 100C temp but some folks say 0W30 "is too thin to run in the summer".......LOL, they obviously don't know their oils.

 

The answer is in the owners manual. I don't understand why people struggle with this.

 

Laziness.... that's just the cold hard truth.

 

When that Jeep manual was written, there possibly wasn't any 5W30....for sure no 0W30.

 

I always figured so many people buying used XJs didn't get the user manual with it

 

Or the jack and lug wrench.

What do people do with those things anyway?

 

weight reduction! lol