I changed the thermostat and water pump in my 08 grand Prix and now the temperature guage goes down when I drive and returbs to normal when stopped.I have bled the bsystem what else could it be?Bad thermostat?
Not running hot at all.When I drive it goes completely to the bottom and have no heat.When I stop it goes up to normal and the heat will then blow
It certainly sounds like the sending unit to me. I had a sending unit go out on a Ford and most of the time the gauge said the engine was running dangerously cold, but I knew it was just the sending unit. I put a new sending unit in, and now the gauge says it runs in the middle of the range in every day and higher in stop and go. The picture is from Rockauto.com parts website where the sending units go from $7.63 to $16.95 plus shipping.
The sending unit only helps measure heat. It does not create it or remove it so if the car is running so cold that the heat stops blowing it is definitely not a sending unit. It could be a thermostat stuck wide open so I would take a second look at it to make sure it is working and is installed correctly.
Looking for a Used Grand Prix in your area?
CarGurus has 3,725 nationwide Grand Prix listings starting at $1,995.
Search Pontiac Grand Prix Questions
Pontiac Grand Prix Experts