Join Date: Feb 2005
Location: Tyee Capital of Canada
Your coolant is leaking somewhere, either externally or internally.
Internally: into your engine oil, radiator, automatic transmission, or exhaust.
Externally: Water pump, hose, radiator,rad cap, heater core , thermostat housing, freeze plug,reservoir, (fill in the blank__________)
Why not open your hood when you hear the gurgling sound and see if you can pinpoint where it is coming from. It sounds like the coolant may be boiling, be very cautious of scalding water if you decide to remove the radiator cap under these conditions.
The reservoir coolant will only go back into the radiator under the partial vacuum that is created when the coolant cools, and contracts.