2001 C5 Coupe
Team Owner
Joined: Jul 2006
Posts: 22,114
Likes: 4,138
From: Kannapolis NC
If you needed a thermostat it would run hot at higher speeds too. At speeds under 35 mph the fans run to cool the radiator when the temps get to the set point of the fans. When it gets hot check to see if the fans are running. Or turn on the a/c, the fans should come on slow speed at any temp above 186 ( or close) at speeds below 35. I had the same issue and I had a 30 amp fuse blown under the hood. There is a separate fuse for each fan in the fuse box. There are also relays, but first check to see if the fans are running. Whether they are or not, check up underneath between the radiator and the a/c condenser where the air is forced up into the radiator. If leaves, grass, plastic bags, etc get sucked up in there (and they will), air flow is reduced and causes overheating.
FIRST STEP, if it only overheats at slow speed, make sure the fans are running. Also, what temperature are you calling "hot"?
FIRST STEP, if it only overheats at slow speed, make sure the fans are running. Also, what temperature are you calling "hot"?
