Obstructed Coolant Flow
WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.
Possible causes of insufficient engine coolant flow are as follows:
- Improper heater hose routing.
- Low engine coolant.
- Pinched, kinked or plugged heater hoses.
- Plugged heater core.
- Plugged heater hose supply and return ports at the engine.
If proper coolant flow through the cooling system is verified, and heater outlet air temperature is still low, a mechanical problem may exist.