Without knowing more about the car like how many miles,how old what kind etc etc i can tell you that if its not leaking coolant and there is not bubbles in your radiator then you either have a plugged waterjacket or bad waterpump. So hard to tell for sure without more info. You can have a blown headgasket,bad valves,or many other things but without knowing how many miles on the engine i do not want to guess. Bottom line is, look for the obvious first. BUbbles in coolant is a sign of internal problems. Have the radiator checked out. I think autozone will look at it for free.
did you change the thermostat
if it has a plastic impeller inside water pump it may be broke or faulty thermostat .check by boiling in water till temp its suppose to open
Water pump maybe?
why does my 2002 chevy cavalier over heat after i change the thermostat and the water pump
heater core....
the gas stays on but the water still doesn't get hot
In a hot water heater, a thermostat regulates the heat
Change the thermostat. lol. Simple but the water pump wont work if the thermostat is stuck closed. Good luck. Kyle
change the thermostat
problem will be in heat control switch in dashboard
If you are unsure if it is heating because of a water pump or a thermstat, you can find out by removing the thermostat. If it still heats without a thermostat, then you know it is the water pump. Without a thermostat, the water flow has nothing to cause it to heat unless the water pump fails to circulate the water. No circulation of the water would cause the over heating.
No heat in your car may be from your water pump going out and not feeding your heater core with enough water to produce heat. First remove your thermostat and see if your car stops over heating. If it doesnt, then you need to replace your water pump. Hopefully you havent cracked your heads. If your car doesnt over heat after removing the thermostat, but you still have no heat in the car. Then its your heater core that needs replacing. Always replace your thermostat whenever replacing the water pump.