sound of fluid when starting

[slutvs]

hey guyssss, just a question i own a vs and whenever i start it sounds like theres some kind of liquid running down behind the dash or back of the engine? got no idea what it is and just curious incase it could be something really wrong?? cheers!

 

[Burnout124]

air in the cooling system air is going througn the heater core. check you water and look for leaks and bleed the system .