Pontiac Problems? Ask a Mechanic for Answers ASAP
Hello, my name is Bobby. Thank you for the question. Can you tell me if the temperature changes at all when you move the temperature to hot?
Thank you. It sounds like you either have a clogged heater core or the failure of a blend door actuator under the dash. The actuator is a much more common issue. Start by checking the coolant level. If it is low then this will occur. If the coolant is fine see if both heater hoses are hot when the engine is warm. If they are not both hot then it is clogged. If they are then it is an actuator issue.
Without a scan tool these cannot really be tested. When you move the temperature from hot to cold you should see it moving back and forth. If not it is bad. You need to remove the glove compartment to access it.