Bought a '98 Accent a while ago to drive back and forth to work and so far it's been great. 30+ MPG. Coming home the other day happen to notice the Temp gage is pegged in the Cold direction. Started messing with the heater and found that isn't working as well, just blows cold air. First instinct, change the thermostat. After removing the thermostat and tossing it in the snow and watching it close figured it was good but put the new one in anyway. Still no heat and the Temp gage barely moves. Seems as though the radiator lines are pressured and plenty warm as well as the heater core hoses but that may be radiant heat from the motor. No leaks either. The Chiltons book says that the heater system includes and uses vacuum and vacuum lines? Never heard of it but I ain't a mechanic. This is Montana and I WANT HEAT ... If you help I will consider you a genius and you will get all the bragging rights that say you had the answer. Thank you for reading.

 

After looking at the book further, seems as though the vacuum lines only run the little trap doors that direct which vents the hot air comes out so scratch that.

 

Check the belt driving the water pump? Make sure all the air is out of the block cavity? To be honest, I'm a bit stymied that the temp sensor is pegged low. Sounds like the thermostat is stuck open, but that certainly should not be true with a new one in place.

 

Is your radiator fan running continuasly?

 

Nope... in the time I have spent under the hood lookin around tryin to figure this out, the fan as yet to come on.

 

Replace the temp sending unit. That should get the gauge fixed. It might get the heater running too.

 

Both temp sensors have been changed and I have flushed the system. The problem is still there. The car just takes forever to get warm and the heater doesn't work. Is it possible that the water pump isn't circulating the water to where the warm water just isn't flowing through the system? How can I tell if the pump is working?

 

Put some cardboard in front of the radiator to block the airflow. Does it heat up that way?