I was driving and all of a sudden the temp shot up, so i quickly turned the car off. the car does not have heat because either the valve/pump that allows water to go through the heating core does not work and needs replace...so i think, and have been told. I just replaced the thermastat in the car about a month ago, coolent levels were fine.....any ideas?
-Thanks

 

Possibly an airlock in the system? Did the heater stop working after the thermostat change?? Give the top hose a squeeze to see if there's water in it. Not sure how the cooling system should be bled on these, but repeatedly squeezing the top hose hard, with the engine running & header tank cap off should help if it's this...

 

the heat didnt work prior to the thermostat change, i check the fluid levels......we burped the cooling system so there is no air in it.....i cant think of anyting else it could be.......
thanks though

 

We see a lot of water pump failures. The impellor is plastic and either snaps or spins on the shaft.
It is not hard to get off and there is an upgraded pump available.

 

I suspect the water pump.

 

I just had to replace the thermostat on my '99, which was overheating. I would definately try replacing that piece first, for it is relatively inexpensive to replace. You may have gotten a faulty Tstat...it does happen.