Causes of Odor

Causes of Odor

• Odors from the air conditioning system can be caused by various things, only a portion of these orders come from the evaporator and can be corrected by cleaning it with the Ultrasonic HVAC Cleaning System (VAS 6189).

• Smell like burnt oil.

- Mostly forms in the engine compartment due to leaks on the engine or transmission.

• Sulphurous smell like exhaust.

- Due to leaks in the exhaust system.

- Due to exhaust that enters the vehicle, when driving in reverse by driving through the cloud of exhaust.

• Fishy smell like coolant.

- From leak at cooling system of engine or of A/C system heater core.

• If fishy odor is detected also in fresh-air mode as well as in recirculated-air mode, check A/C system heater core for proper seal.

• Smell like a burned clutch.

• Evaporation from floor mats, decorative seat covers, etc.

• Rotten, mildewy, moldy or musty smell from plenum chamber.

- Due to various contaminants, such as leaves, pine needles, etc. collecting.

- From water which cannot flow out of the plenum chamber or air intake housing.

• Check water drains of plenum chamber and air conditioner. Refer to=> [ Checking and Cleaning Plenum Chamber Water Drain ] Checking and Cleaning Plenum Chamber Water Drain

• Smell from air conditioner.

• Odors originating in heating and A/C unit can mainly be detected in fresh air mode as well as in recirculated air mode. If a smell occurs only in fresh air or recirculation mode, the cause is probably not the A/C unit.

• When heater core is leaking, the odor of the escaping coolant can be detected even in fresh air mode as well as in recirculated air mode heater core has continuous air flow.

- Due to too much condensation water in A/C unit.

• Check both condensation water drains. Refer to=> [ Condensate Drain Hose ] Description and Operation.

- Due to an old or heavily contaminated dust and pollen filter.

• Check dust and pollen filter. Refer to => [ Dust and Pollen Filter ] Air Distributor Housing

- Due to deposits on evaporator fins.

• Clean evaporator with Ultrasonic HVAC Cleaning System (VAS 6189). Refer to=> [ Cleaning Evaporator ] Cleaning Evaporator.