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).

=> [ Evaporator, Cleaning ]

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 is detected also in recirculated air mode as well as in fresh 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 of air intake housing => [ Plenum Chamber Water Drain, Checking, Cleaning ] Plenum Chamber Water Drain, Checking, Cleaning.

• 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 => [ Condensation Drain Hose ] Condensation Drain Hose.

- From an old or severely soiled dust and pollen filter.

• Check dust and pollen filter => [ Dust and Pollen Filter ] Dust and Pollen Filter.

- Due to deposits on evaporator fins.

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

Evaporator, Cleaning

Special tools, testers and auxiliary items required

• Ultrasonic HVAC Cleaning System (VAS 6189).

• Cleaning Fluid (VAS 6189/1)

• Standard vacuum cleaner and Suction Nozzle (VAS 6288).

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 plenum chamber and water drain valves installed there and clean them if necessary => [ Plenum Chamber Water Drain, Checking, Cleaning ] Plenum Chamber Water Drain, Checking, Cleaning.

- Remove dust and pollen filter and check it for odor and contamination => [ Dust and Pollen Filter ] Dust and Pollen Filter.

• On this vehicle, the dust and pollen filter is installed between Fresh Air Blower (V2) and evaporator, therefore it must be removed for the cleaning.

- Clean the dust and pollen filter installation shaft at the A/C unit of leaves, dust and other contaminants using a standard vacuum cleaner, Suction Nozzle (VAS 6288) (and hose attachment) => [ Dust and Pollen Filter ] Dust and Pollen Filter.

- Reseal opening on A/C unit through which dust and pollen filter was removed.

- Start the 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 "Lo").

- 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 up the ultrasonic HVAC cleaning system (VAS 6189) (according to operating instructions) and route the outlet hose belonging to it so that the vapor escaping via the recirculated air opening of the heating and A/C unit (beneath instrument panel) is drawn in by the 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.

- Install dust and pollen filter => [ Dust and Pollen Filter ] Dust and Pollen Filter.