Obstructed Coolant Flow

WARNING: This page is about a different car, the 2010 Dodge Charger and 2010 Chrysler 300. However, it is still accessible from the selected car via links, so may be relevant.

Possible locations or causes of obstructed coolant flow are as follows:

Inoperative water pump.
Inoperative thermostat.
Pinched or kinked heater hoses.
Improper heater hose routing.
Plugged heater hoses or supply and return ports at the cooling system connections.
Plugged heater core.

If proper coolant flow through the cooling system is verified, and heater outlet air temperature is low, a mechanical problem may exist.