I have 2003 Monte SS.When I start my car and put it in drive and press on the accelerator it sounds like water swishing in the firewall of the car. It runs great,just can't figure out wheat the water noise is. Any answers?
Could be coolant in the heater core, coolant might be low or there might be an air pocket in the cooling system. Should be looked at by your local authorized Chevy dealership to determine if there is a leak or an air pocket in the cooling system.