Heater Core-Plugged
WARNING: This page is about a different car, the 2004 Mercury Mountaineer and 2004 Ford Explorer. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
The heater core inlet hose will become too hot to handle if the system is working correctly.
- Check to see that the engine coolant is at the correct level.
- Start the engine and turn on the heater.
- When the engine coolant reaches operating temperature, feel the heater core inlet and outlet hose to see if they are hot.
If the inlet hose is not hot:
- the heater control valve may be stuck closed.
- the thermostat is not working correctly.
If the outlet hose is not hot:
- the heater core may have an air pocket.
- the heater core may be restricted or plugged.