On some 2007-2008 Honda Fit models, a gurgling noise may occur behind or underneath the dashboard at engine idle, under light acceleration or during deceleration. The likely cause is air trapped in the heater core. It will be necessary to bleed the cooling system.
- Make sure that there are no cooling system leaks and make sure that the radiator cap is functioning properly. Allow the engine and radiator to cool completely before loosening the radiator cap.
- With the engine cool, open the radiator cap and place the cap loosely on the filler neck.
- Start the engine and allow it to idle until the engine is warm and the cooling fan has cycled on and off twice.
- Turn the ignition switch to LOCK and remove the radiator cap.
- Fill the radiator with coolant to the base of the filler neck, and fill the coolant reservoir to the MAX mark. Note: Honda recommends using ONLY Honda Long Life Antifreeze/Coolant Type 2. Do not add water to this coolant (the Honda coolant is premixed).
- Install and tighten the radiator cap and let the engine cool to ambient temperature. Blow air over the engine with an electric fan to cool it more quickly. The coolant level in the reservoir should drop from the MAX mark and approach the MIN mark as the engine cools. If the coolant level does not drop, check for cooling system leaks or a faulty radiator cap.
- When the engine is cool, fill the coolant reservoir to the MAX mark. Do not loosen or remove the radiator cap.
- Test drive the vehicle and make sure that the noise is gone. If the heater core still gurgles, repeat the process.