I've got a 2004 grand prix GT1 3.8v6 and AT with 120k miles. I noticed the temperature gauge rising when I was at a stop and after popping the hood and looking, the coolant overflow tank was nearly full and seemed gunked up. I don't think the fans are kicking on at all when idling also. Could the water pump have possibly gone out?
Friday, March 25th, 2011 AT 3:40 AM