Thermostatic Air Cleaner (THERMAC) (1.6L Engine Only): Testing

1. Ensure heat tube is fitted to heated air inlet and damper door in air cleaner has freedom of movement. Check that damper door spring is attached and pulling door against "wax pellet" type actuator. Ensure air cleaner to TBI base gasket and cover seal gaskets are in place.
2. Check that damper door is open to heated air inlet when engine is not running and temperature is cold. Observing damper door through cold air inlet, start engine and ensure damper door is closed to outside cold air. As engine warms over a period of several minutes, damper door should open slowly to outside air. If not, replace actuator or filter assembly.

Fig 1: Thermostatic Air Cleaner (THERMAC) System

Courtesy of GENERAL MOTORS CORP.