Owners of 2007-08 Fit compact cars may complain of a gurgling-type noise from under the dashboard at idle, under light acceleration or during deceleration. One likely cause for the annoyance, reports Honda, is an airbound heater core. Bleeding the core should eliminate the condition immediately. Here's how to go about it:
Start by loosening the radiator cap. Next, start the engine and allow it idle until the electric cooling fan has cycled on and off twice. Now turn the ignition off and carefully remove the radiator cap. Fill the radiator with coolant until it reaches the base of the filler neck, then add coolant to the reservoir until it aligns with the MAX mark. Install and tighten the radiator cap, then allow the engine to cool to ambient temperature. Once it does, check the coolant level in the reservoir. It should be down near the MIN mark. If it didn't drop, check for a leak or a bad radiator cap. If the level did drop, fill the reservoir to the MAX mark. To complete the fix, go on a road test to verify that the gurgling noise has been eliminated. If it hasn't, repeat the bleeding procedure.