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, for example, the Ultrasound A/C Cleaner (VAS 6189A).

• Smells like burnt oil.

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

• Sulphurous smell similar to exhaust.

- Due to leaks in the exhaust system.

- Through exhaust fumes, which get into the passenger compartment, for example, when driving in reverse through an exhaust gas cloud.

• Fishy smell like coolant.

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

• If fishy odor occurs depending on temperature setting (weaker at "Lo" temperature preselect / at "cold" setting than at "Hi" temperature preselect / at "warm" setting), check heating and A/C unit evaporator for leaks (heater core does not have continuous air flow).

• Smells 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.

- Due to water that cannot drain out of the plenum chamber.

• Check plenum chamber water drains. Refer to=> [ Plenum Chamber Water Drain, Checking and Cleaning ] Testing and Inspection.

• Smell from air conditioner.

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

• If heater core is leaking, the odor of escaping coolant depends mainly on the temperature setting, air does not flow continuously through heater core at a "Lo" temperature setting / at "cold" setting and the odor is not perceived as strongly.

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

• Check condensation drain. Refer to=> [ Condensate Drain Hose, Checking ] Condensate Drain Hose, Checking.

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

• Check dust and pollen filter, refer to => [ Dust and Pollen Filter ] Service and Repair.

- Due to deposits on evaporator fins.

• Clean evaporator with Ultrasound A/C Cleaner (VAS 6189). Refer to => [ Evaporator, Cleaning with Ultrasound A/C Cleaner ] Evaporator, Cleaning With Ultrasound A/C Cleaner.