1997 Jeep Cherokee.

Anyways, I was on my way back from the bank on a hot Florida day. Temp gauge read ~215 which is pretty normal. Stopped at a red light to wait for the green arrow to turn left and BAM! Warning light comes on and I get beeped at and suddenly im at 250. I made a quick u turn and went to go park it and let it cool down while I got something to eat.

As im going down the aisle to pull into a parking space the gauge jumps back to ~210 and the warning light goes off.

What gives? Thermostat is brand new and I have plenty of coolant. My dad thought the wsater pump could be going bad or is cracked or something, and I do sometimes get a noticeable coolant smell. It has done this once before.

Thanks.

 

have you bleed the air out of the cooling system after you replaced the thermo?

 

How old are the other cooling system components?

 

sound like bad sensor,or plugs loose to it