Pinpoint Test F : Insufficient, Erratic Or No Heat: Notes
WARNING: This page is about a different car, the 2018 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
Insufficient, Erratic Or No Heat
Normal Operation and Fault Conditions
When the engine is at operating temperature hot coolant flows from the engine coolant pump through the heater core and back to the engine coolant pump. Correct coolant temperatures are critical for good heater performance.
Possible Sources
- Low engine coolant level
- Missing or broken engine coolant hose check valve or incorrect orientation of check valve
- Temperature door actuator(s)
- Temperature door actuator(s) binding or stuck
- Plugged or partially plugged heater core
Visual Inspection and Diagnostic Pre-checks
- Inspect for low engine coolant level.