Wagoneer L6-258 4.2L VIN C 2-bbl (1982)
Thermostatic Air Cleaner: Testing and Inspection
Heated Air System
1. Remove air cleaner assembly from engine and allow to cool to ambient temperature.
2. After cooling, observe position of air valve. It should be fully open to outside air.
3. Install air cleaner assembly and connect hot air hose and vacuum line, then start engine and observe position of air valve. It should be fully closed
to outside air.
4. Move throttle rapidly to 1/2 to 3/4 opening and release. Air valve should open and then close again.
5. After engine has reached operating temperature, the air valve should be open to outside air.
NOTE: If air valve does not close at room temperature with vacuum applied, check for a mechanical bind in the snorkel, vacuum motor linkage
disconnected, vacuum leaks in hoses or connections at vacuum motor, thermal sensor or intake manifold. If air valve mechanism operates freely and no
vacuum leaks are detected, connect a hose from intake manifold vacuum to vacuum motor. If air valve now closes, the thermal sensor is defective. If air
valve does not close, vacuum motor is defective.
