1989 & 1990 xj's had this POS Korean cooling system with the bottle on the passenger side firewall. i had a 1990 & ended up just swapping out the radiator with a 1991 xj & putting a little piece of rubber under the new radiator to make it mount right. never had a problem after that. the 89 & 90's also had different ecu's than the other years. they also had that vacuum lock on the front axles on the passenger side of the axle tube & that wasnt good either. if you had any fluid leak it would effect that. i ended up putting in a cable lock there too.

93 xj stroked 4.2 w/4.0 head avenger supercharged 6.5" long arm 35" buckshots rubicon 44's front & rear