Is there not a rubber tube just below the rad cap that leads to a overflow bottle????? Sounds like u already have a "open" system.

 

There is supposed to be one but there's not. I'm confused now, because my year XJ comes stock with a closed cooling system.

 

Exactly. And those never had caps on the radiator...

Again....

 

Sounds like the PO has put a "open" type/later model rad in your XJ but half-xxxed it.

 

Yep. Sounds like it indeed.

 

I completely agree unless I'm wrong on the year and it's actually a '91.

 

This thing called a "title" would have that info...
Or the emissions sticker
Or the door sticker
Or...

Just post a pic of your setup, so you can get some help, youre obviously confused on the open vs closed thing.

 

i wrote this a while agohttps://www.cherokeeforum.com/f2/ren...d-shift-63044/

 

just hook the heater core up straight from the motor ,i hooked mine backup this year no issues from doing this