98 Cherokee Limited 4.0 overheating

[charger72v8]

1068182

Im getting frustrated. Ive neevr seen something like this before. The weather is just starting to heat up here. I am overheating to the red line and then after a minute or two it will drop back to normal. Collant is good thermostat was just replaced. It only seems to happen if I drive about 15 minutes with the A/C on.
Help...what could it be?[addsig]

 

[2001sah]

1068187

i'm no jeep wiz myself, but my friend has one and he said his 93 theromstat went a lot. i guess they're known to go pretty easily. not sure though.[addsig]

 

[CHIFFG]

1068188

Do you have the right temp thermostat?
Do you have a good 50/50 antifreeze - water mix?
When is the last time the system was completly flushed?
Is the belt properly tensioned for the water pump?
Is the water pump warn out?

The last 2 more than likely aren't the problem but are possible[addsig]

 

[XJNick]

1068205

If it only overheats with the A/C on, check that the electric fan on the radiator comes on and stays on when you turn the A/C on. Is your A/C blowing cold? If there is a problem with the A/C system causing the condensor (coils infront of the radiator) to overheat, your radiator won't be able to keep the engine coolant from overheating.

-Nick[addsig]

 

[carriss]

1068213

i had the same prob there was too many bugs in the fins? any way i sparyed it out with the hose and now it's fine[addsig]

 

[dingus]

1068272

98 cherokee? electrical cooling fan, and electric AC fan? maybe a wire is screwed up... when the AC kicks on, the main fan kicks off... and the AC fan can't keep up. pop the hood and watch what happens...[addsig]

 

[EddyB]

1071094

Also might ch3ck the temp sending unit........Small brass colored fitting that sits on top of the water pump..... 21.00 replacement from autozone[addsig]