Buick Regal: Odor Correction

Eliminating Air Conditioning (A/C) Odor

Odors may be emitted from the heat and air conditioning system primarily at start up in hot, humid climates.

When the blower motor fan is turned on, an unpleasant, musty odor may be released into the passenger compartment. The following conditions may cause the odor:

• Debris is present in the heater and air conditioning evaporator and blower module.
• Microbial growth is on the evaporator core

The following procedures should be completed to eliminate most common sources of odor:

1. Use the scan tool to enable the afterblow function, if heater and air conditioning remote control has this functionality.

2. Ensure that the fresh air inlet is clear of debris.

3. Verify that the heater and air conditioning evaporator and blower module drain is not blocked. If the drain is blocked, remove the debris and dry the heater and air conditioning evaporator and blower module performing the following procedure:

1. Start the engine and allow the engine to reach operating temperature.
2. Open the vehicle windows.
3. Select the hottest temperature setting.
4. Select the recirculation mode.
5. Run the blower motor on high for 10 minutes.

4. If equipped, remove the passenger compartment air filter and examine for debris or odor.

1. Take care upon passenger compartment air filter removal to prevent debris on top of the passenger compartment air filter from falling into the heater and air conditioning evaporator and blower module.
2. If the filter is dirty or suspected as the source of the odor, replace the passenger compartment air filter.
3. If the debris has fallen into heater and air conditioning evaporator and blower module, remove the blower motor to remove the debris.

5. If this procedure is unsuccessful in eliminating the odor, perform the AC Delco Cooling Coil Coating procedure if it is available in your market. If the AC Delco Cooling Coil Coating is not available in your market, perform the water and vinegar solution cleaning procedure.

AC Delco Cooling Coil Coating Procedure

The evaporator core and heater and air conditioning evaporator and blower module should be treated with AC Delco Cooling Coil Coating to eliminate microbial growth. Adhesives, Fluids, Lubricants, and Sealers Perform the following procedure:

1. Disable the air conditioning compressor clutch operation by disconnecting the air conditioning compressor clutch coil electrical connector.

2. Start the engine and let the engine idle.

3. Select the hottest temperature setting.

4. Select the heater and air conditioning evaporator and blower module controls to the recirculation mode.

5. Run the blower motor on high for 10 minutes.

6. Place a drain pan beneath the heater and air conditioning evaporator and blower module drain tube.

7. If equipped, remove the passenger compartment air filter.

8. Place protective shop cloths or equivalent over outlet ducts to prevent overspray.

9. Locate an area in the heater and air conditioning evaporator and blower module downstream of the blower, between the blower motor and the evaporator core. Drill a 3.175 mm (0.125 in) hole where the hole will not interfere with or damage the blower motor, blower motor speed controller, evaporator core, or any other operating part the of system.

10. Set the blower speed to maximum high speed.

11. Set heater and air conditioning evaporator and blower module controls to floor outlet mode.

12. Close all air conditioning outlet vents.

13. Wear an approved respirator mask, safety goggles, and latex gloves when applying the AC Delco Cooling Coil Coating.

14. Insert the applicator extension tube into the hole to the mark on the extension tube, ensuring the spray is aiming the same direction as the airflow. Coating should be applied in 3 second bursts with the nozzle being repositioned within the case between bursts until all 4 ounces of coating are applied.

15. Shut the engine OFF. Allow the vehicle to sit for 3 - 5 minutes.

16. Seal the 3.175 mm (0.125 in) hole with body sealer or RTV gasket compound.

17. To cure the Cooling Coil Coating:

1. Start the engine and let the engine idle.
2. Lower one side door window 1/2 inch, 12mm.
3. Set the blower speed to maximum high speed.
4. Set heater and air conditioning evaporator and blower module controls to floor outlet mode.
5. Select the hottest temperature setting.
6. Let the vehicle idle for 10 minutes.

18. Reconnect the air conditioning compressor clutch coil electrical connector.

19. Verify proper air conditioning compressor clutch operation.

20. Reinstall the passenger compartment air filter if necessary.

21. Remove the protective shop cloths from inside the vehicle.

22. Ensure the afterblow function has been enabled.

Water And Vinegar Solution Cleaning Procedure

If the AC Delco Cooling Coil Coating is not available perform the following steps:

1. Remove the evaporator core.

2. Clean evaporator core with a solution of 40% vinegar and 60% water.

3. Reinstall the evaporator core.

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