Pontiac Grand Am no warm air through air ducts despite recent heater core and thermostat replacement on Pontiac Grand Am

Submitted by daugherty · Jun 23, 2025
Published by RepairPal

Problem overview

Some Pontiac Grand Am owners report experiencing issues with warm air not coming through the air ducts, even after replacing the heater core and thermostat. These problems may be linked to a stuck air/mix actuator, which can prevent proper switching between heat and A/C settings, despite the hoses being hot. Additionally, low coolant levels can hinder the flow of coolant to the heater core, resulting in insufficient warm air circulation. A clogged heater core may also restrict coolant flow, causing the air to cool before reaching the cabin. Some owners find that air pockets in the cooling system disrupt the circulation of warm coolant, while others encounter problems due to a malfunctioning thermostat that affects heating system operation. Furthermore, issues with the blend air door can impact the distribution of warm air, and low coolant pressure may compromise the heater core's ability to receive adequate coolant. It is crucial for owners facing these heating system problems to investigate these potential causes for effective resolution.

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Pontiac Grand Am vehicles with this problem

Average mileage: 123,000 miles
(123,000 - 123,000)

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