07 Unlimited X Overheating

[GCFolkes]

I have an Unlimited X 4x4 that has just started overheating. It is a 6 speed with a/c. It cools down at higher speeds and heats up at idle. I have replaced the thermostat and check both the upper and lower hoses with a infrared thermometer and the temperature is within a few degrees of being the same. The fan which is electrical does not come on right away nor does it come on very fast. It comes on very low and then turns off.
Any suggestions as to what part I should be looking to replace...fan motor, relay or ???
Has anyone had anything similiar to this happen?

 

[TerryMason]

Does it overheat when you're on the highway, or when you are sitting still (i.e. will it overhead if you leave it idling in your driveway).

 

[JPNinPA]

I have an Unlimited X 4x4 that has just started overheating. It is a 6 speed with a/c. It cools down at higher speeds and heats up at idle. I have replaced the thermostat and check both the upper and lower hoses with a infrared thermometer and the temperature is within a few degrees of being the same. The fan which is electrical does not come on right away nor does it come on very fast. It comes on very low and then turns off.
Any suggestions as to what part I should be looking to replace...fan motor, relay or ???
Has anyone had anything similiar to this happen?

Does it overheat when you're on the highway, or when you are sitting still (i.e. will it overhead if you leave it idling in your driveway).

GCFolkes - above 35 mph your temp should be stable at the correct temp even if the fan is inoperable. If it is higher than normal temp then there is another cause. Maybe two issues. When your fan kicks on there should be enough air flow to hold a sheet of paper to the grill.
If it is above temp when traveling 35 mph post back otherwise check all fuses and wiring to the fan.

When you replaced hoses etc did you use the specified coolant at the correct blend? Did you burp the air out of the system? And have you verified the coolant is circulating?