ok i kno this isnt technically a cherokee but the are all but the same and i really need help and kno that nothing gets seen in the other vehicals section so if im in the wrong place im sorry.
i have an 86 jeep grand wagoneer with a 5.9l. its over heating. right not its got a new water pump, new radiator, i took the thermostat out to elimate it possibly sticking. whats left? i thought that fan possibly since its a clutched fan but it does spinn. even at high rpm it spins. is there any way to check the fan? or any other ideas of what the problem could be?

 

Could be clogged. Have you flushed radiator lately?

 

Is your clutch fan actually engaging? it could still spin and not be engaging. does it sound like a 747 taking off under the hood when it get really hot?

 

we flushed the system when we put the radiator in. its only been a few days. and im not sure. my boss was driving it when it over heated. if it was loud what would that mean? im not to sure i fully understand what the fan clutch actually is there for

 

An 86 Grand Wagoneer is a Cherokee, it just happens to be a FULL Sized Cherokee.
Mechanical fans always rotate if the motor is turning. As the ambient temp increase the clutch increases the friction on the shaft the fan spins on, thus increasing the speed the fan spins. So when cold the fan will spin at say 50% of the engine RPM, as the temp rises the clutch engages more and more, increasing the fans speed to 70%-90% of the engines RPM. The faster the fan spins the louder it gets. Removing the T-stat can cause overheating, by not holding the coolant in the radiator long enough for the air to cool it. A bad radiator cap can cuase over heating by not allowing enough pressure to build in the system and reducing the boiling point. There are many causes of over heating starting with the cooling system, but , including Fuel mixture, ignition timing, block and head issues and transmision problems can contribute.

 

i just now took the tsate out. i was in when it over heated. i took it out to test it. and the boss man said leave it out. ill make sure it goes back in now tho. i kno the cap is good. i checked that and it tested fine. i though about maybe a fuel mixture problem but didnt quite kno how to look into that issue. the fan doea spin. how can i tell if its spinning paster as it gets warmer? will it be easy to just listen and hear the change?

 

Yeah you will be able to tell by the sound. You can also tell by feel. With a cool motor and turned off, spin the fan by hand, remember the amount of resistance you feel. Now get it fully warmed up and do the spin test again, the fan should feel significantly tighter.

 

ok cool. ill give that a shot and see what happens.