Heater Core - Plugged
WARNING: This page is about a different car, the 2003 Mercury Marauder, 2003 Mercury Grand Marquis, and 2003 Ford Crown Victoria. 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 outlet hose to see if it is hot.
If it is not hot:
- The heater core may have an air pocket.
- The heater core may be plugged.
- The thermostat is not working correctly.