Having problems with your 2000 Pontiac Grand Prix ?
Heat goes in and out and the temp gauge goes up and down
\015 Heater blows out hot air then it goes cold . I watched the temp gauge go up and down when it does this when the gauge rises to normal operating temps the air comes out cold then when it dropes down below that it blows out hot air\015
Your temp sensor has nothing to do with your heater. The temp sensor needs coolant in order to work properly. So first check the coolant level because if it is low your heater will act the way you describe. Once the coolant gets low enough the heater will blow cold. Another possibility is the radiator cap. After the engine has warmed up it expands when it cools down it contracts. As it is contracting if the cap is weak air can be drawn into the system and cause air pockets to form and will cause the same problem
Repair Help & Product Troubleshooting for 2000 Pontiac Grand Prix
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