Engine Cooling System

Questions about the engine cooling system?  

General Cooling System Info

 There are 2 types of Cooling systems on the XJ/MJ

  1. Open style - any normal cooling system used today.
  2. Closed style - no radiator cap and utilizes a pressure bottle. used in 87-90 XJs.

MAINTENANCE SCHEDULE

  • Change engine coolant every 12,500 miles or 12 months.
  • Thereafter change engine coolant at the beginning of every winter season.
  • Maintain ethylene glycol and water solution at a mixture of 50/50.

 

Cooling System Specs

Application

Thermostat

Temp F (C)

Rad. Cap

PSI

Coolant Capacity

Quarts (L)

2.5L 192-198 (89-92) 12-15 10 (9.4)
4.0L 192-198 (89-92) 12-15 12 (11.3)
4.2L 192-198 (89-92) 12-15 10.5 (9.9)
6.0L 192-198 (89-92) 12-15

14 (13.2)

(1) - Without A/C 23 qts. (2.1L) for recovery tank.

(2) - Includes 1 qt. (.9L) for recovery tank.

Coolant Temperature Sensors

  • the 99 XJ has only 1 coolant temp sensor which is located on the Thermostat Housing

Cooling System Upgrades and Tech Write-ups