Originally Posted by carlyj
Driving home today in 108º weather here in sunny Las Vegas, Nevada and remembered I needed a few things from the Walmart. Stopped at one near my house, turned the Jeep off. I wasn't inside for more than about 10 minutes and when I get back in my Jeep and turn it on, the first thing I notice is the temp at damn near 260º. After running for about 5 seconds the temp stabilized at about 210º where it's supposed to be.
Is it normal for it to do this? I've noticed it before even in colder weather.
When an engine is shut down core temperatures sky rocket. Coolant temperature increase AFTER engine shutdown is a normal condition.
Operating temperature of 210 degrees F is a normal condition as well. The fact that you restart and engine temperature returns to normal operating temps tells me your cooling system is working.
I wouldn't recommend running out and replacing parts. Check your cooling system over when its cool, and then hot.
First...make certain your coolant level in the radiator is at the fill neck. If it's low you will need to add coolant and possibly bleed the system of trapped air...this is another process for another post.
Consider replacing coolant if its older than 3 years.
Check your radiator cap. Have your shop pressure test it.
Check your hoses and clamps. Replace old, cracked or swelling hoses.
Check your fan clutch. With the engine off, spin the cooling fan manually by hand. It should spin but with some resistance. If the fan spins feely you need to replace the fan clutch.
Check for debri and BUGS on the front side of the radiator.
I think this is enough to get you started and give you some peace of mind. It's HOT out so expect higher temps.