Zab243

My 1991 jeep Cherokee xj is over heating while in 4x4 it has 217xxx miles orginial motor. It runs normaly 160-180. But in 4x4 it's running past 210. what could cause this? It has the 4.0 I6

robertj

It should run at 210 all the time. 160 to 180 is not normal and could indicate your thermostat is stuck open. Also, I doubt it has anything to do with the fact that you're in 4x4 but rather that you're crawling or going slow compared to RPMs. If the thermostat is stuck open it can negatively affect your XJs ability to cool due to the coolant not holding in the radiator as the thermostat stops flow. Also, make sure your electric fan is kicking on when it reaches temps above 210. What temps are you seeing?

Zab243

VeI've seen temps run way over 210 around 260. I had to replace my thermastat sensor cause the sensor said the collent was 54 degress causing it not to run. But I have a radar to tell temps and I read the thermastat at 170.

PhilipF18

ya make sure that ur electric fan turns on when your motor is getting hot if it doesnt have it hooked up to an ignition switch so when the key is turned on it will to. i did it with mine and it helps alot.

Zab243

There are 2 fans. One I can control and one to the motor. The one I can control is located by the power steering pump. Then I have my radiator fan. Idk if my radiator fan is working. I will look in to this first thing in the morning. And I'll get back asap