The other night the wife said she was cold so I turned up the heat. I noticed the heated airwould turn cold when stopped for the traffic lights. Rev the engine to 2K and heat would come back.

Traced fault to the Aux coolant pump. Pump had power but stalled because of worn brushes, tap on the body and it would start running. Quick checkon the hoses and confirmed when the pump started the hoses gotwarm.

Dealer said $325 to fix, found pump on line for $165. Easy change, right in front of the coolant tank.

PN for my car was 203-835-01-64

Hope this helps someone someday ;-)