I recently picked up an 88 wagoneer from a buddy of mine. It ran fine up until a few days ago it started having intermittent cooling issues. The problem is consistent now.

In a nutshell: Runs hot while idling, will cool down to normal operating temp when i rev to 1500+ rpm.

just put a thermostat in a few days ago, there wasnt one when i bought it. read that not having a t-stat can cause it to run hot.

Burped it through the sensor in back of head today. same problem persists

Ideas? any help is appreciated, trying to fix it before this weekend!!

Radiator bad?
Water pump?

 

Also, Fan is set to run constantly

 

sounds like the water pump to me, i got my fans set to run constant too

 

Are you running a shroud?

 

if you mean a fan shroud, yes.

 

the mechanical fan clutch is shot. its a cheap, easy fix.

 

could it be the water pump... both fans seem to be running o.k.??

 

could be... i still vote clutch. if the motor doesnt sound like a 747 taking off when its cold in the morning or when the motor is running hot, the clutch is shot.

 

are there any signs or a testing method to determine if it is the fan clutch?