had an overheating problem-- cracked radiator. fixed that and it has ran great for a few hundred miles. also replaced the thermostat at the same time. the last 3 times driving it though it's almost overheated. it will climb up to about 235 or higher, just before the red and stay there for a while (10 miles), then all of a sudden it will drop back down to 200* in about 1 second and then it's good to go for the rest of the trip 10 miles or whatever.

when it's that high i don't hear the fans click on. i know they do work though, as they're on when you start the car. don't think it's a fan issue. it is that hot when cruising on hwy at 60mph which ought to be enough to cool it like the fan.

sounds almost like a stuck thermostat to me, but damn it's new.

car runs great otherwise. plenty of coolant. doesn't seem to have any air bubbles and has went through a dozen cooling cycles since radiator install. also has a new radiator cap.

got me thinking if it might be a bad coolant temp sensor.

any ideas? thanks

 

Sounds like you don't have all the air bled out of the system.

 

the bleeder screws don't bubble. should I just keep letting them bleed out? like i said it has been through a bunch of heat cycles and 200-300 mi since radiator install. how much is enough? come to think of it this did start up after i ran it pretty hard... might have churned up some bubbles somehow? thx

 

On the driver side head by the spark plug is the temp sensor that control the gage on the dash. Check to see if the wire is cut or burnt from exhaust heat.