2001 Chevy Impala rattlling noise under heavy acceler

G'Day there.

The only place that the à nti freeze"smell could come from is a small leak in the heather core or aheater hose under the dash, have the cooling system pressure tested when hot and the heater tap open and chek for any water leaks in or near the heater core. Any leak should fine its way onto the front mats near the heater box.

Mark (mhpautos)