Thermostatic Air Cleaner (TAC) (Trooper 2.8L)

Operation

• With engine off and air cleaner installed, TAC snorkel damper door should be open. When cold engine is first started, damper door should close to outside air. If door fails to operate, perform VACUUM MOTOR CHECK and TEMPERATURE SENSOR CHECK.

Vacuum Motor Check

• Check all related vacuum hoses for kinks, breaks or plugs. With engine off, disconnect vacuum hose at TAC vacuum motor. Using hand-held vacuum pump, apply 7 in. Hg to motor. Damper door should close off intake end of snorkel. If damper door does not close, check linkage and door for binding. If no problem is found, replace vacuum motor on air cleaner.

Temperature Sensor Check

1. With engine temperature less than 86°F (30°C), place a thermometer inside air cleaner as close to sensor as possible. Reinstall air cleaner cover. Start engine and let idle.
2. Damper door should close immediately. If it does not, check vacuum hoses to sensor from throttle body and to vacuum motor from sensor. If vacuum hoses and vacuum motor are okay, replace sensor.
3. Observe when damper door opens snorkel passage. Remove air cleaner cover and note thermometer. Temperature should be approximately 131°F (55°C). If temperature is not as indicated, replace sensor.