A/C System Evaporator, Cleaning With VAS 6189

A/C System Evaporator, Cleaning with VAS 6189

• 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).

Causes of Odor

• 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, e.g. 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 occurs depending on temperature setting (weaker with temperature setting "Low" than with temperature setting " Hi"), check the A/C unit heat exchanger for leaks (air does not flow constantly through the heat exchanger).

• 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.

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

• Check that the plenum chamber water is draining.

• 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.

• In the case of a leaking heat exchanger, the odor of the escaping coolant mostly depends on the temperature setting. With the "Low" temperature setting, air does not flow through the heat exchanger and the odor is not as strong.

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

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

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

• Check dust and pollen filter. Refer to => [ Dust and Pollen Filter ] A/C System Control and Regulation Components.

- Due to deposits on evaporator fins.

• Clean evaporator with Ultrasonic HVAC Cleaning System (VAS 6189).

Evaporator, Cleaning

• Clean the evaporator with the Ultrasonic HVAC Cleaning System (VAS 6189).

Tools required

• Ultrasonic HVAC Cleaning System (VAS 6189).

• Cleaning Fluid (VAS 6189/1)

Preparation

- Check whether odor is actually in A/C evaporator by switching from fresh air to recirculation.

• The odor can only be fixed by cleaning with the Ultrasonic HVAC Cleaning System (VAS 6189) if it originates in the evaporator.

- Check the plenum chamber and water drain valves installed there and clean them if necessary.

- Check dust and pollen filter for odor and dirt. Refer to => [ Dust and Pollen Filter ] A/C System Control and Regulation Components.

• In this vehicle, the dust and pollen filter is installed at the intake housing of the A/C unit upstream from the fresh air blower (V2), therefore it does not need to be removed for cleaning.

- Start engine.

- Set operating mode "recirculated-air mode" at front A/C control head Climatronic Control Module (J255) and switch off compressor "Econ".

- Open instrument panel vent and on the operating and display unit, set the Climatronic Control Module (J255) to the lowest possible temperature for the driver's and passenger's side (e.g. temperature selection "Low").

- Close the windows and the sunroof.

- On the operating and display unit, set the Climatronic Control Module (J255) to the lowest fresh air blow level and select "Instrument panel vent" for air flow direction.

Cleaning

- Shake bottle of Cleaning Fluid (VAS 6189/1) and fill Ultrasonic HVAC Cleaning System (VAS 6189 ) with it, following operating instructions that come with cleaning system.

- Place Ultrasonic HVAC Cleaning System (VAS 6189 ) in passenger's side footwell.

- Start Ultrasonic HVAC Cleaning System (VAS 6189 ) (according to operating instructions) and route outlet hose belonging to it so vapor escaping via A/C unit recirculated air opening (in passenger's footwell behind glove compartment) is drawn in by Fresh Air Blower (V2).

- Close vehicle doors.

• The cleaning process takes about 15 to 20 minutes. It is complete when vapor no longer comes out of outlet hose.

Finishing steps

- Switch Ultrasonic HVAC Cleaning System (VAS 6189 ) off.

- Open vehicle doors and air out vehicle at least 10 minutes.

- Remove Ultrasonic HVAC Cleaning System (VAS 6189 ) from vehicle and clean it according to operating instructions.

- Switch off ignition.