A/C Growl or Buzzing Noise (Install Bracket Kit/Thermal Expansion Valve and/or Inspect A/C Compressor Bolts)

This bulletin is being revised to add models, a part number and Step 16 to the procedure. Please discard Corporate Bulletin Number 06-01-39-016A (Section 01 - HVAC)

Some customers may comment on a growling or buzzing noise when the A/C is on.

This condition may be caused by any of the following:

Inspect the A/C compressor bolts and tighten, if necessary.

Install Chassis Ears Electronic Listening Tool J 39570 on the thermal expansion valve. With A/C on and the system stabilized (run for one minute), listen for a buzzing noise with the engine RPM between 1500-2000 RPM. Replace the thermal expansion valve if this noise is detected. Refer to Thermal Expansion Valve Replacement in SI and install the evaporator tube bracket kit (refer to Correction 3).

Install the evaporator tube bracket kit.

1. Remove the left and right wiper arms. Refer to Wiper Arm Replacement in SI.
2. Remove the air inlet grille. Refer to Air Inlet Grille Panel Replacement in SI.
3. Remove the hood release cable from the pencil brace and, if vehicle is equipped with an automatic transmission, remove the breather tub .
4. Remove the pencil brace.
5. Remove the wiper transmission assembly. Refer to Wiper Transmission Replacement in SI.
6. Recover the refrigerant. Refer to Refrigerant Recovery and Recharging in SI.
7. Remove the evaporator tube from the vehicle. Refer to Evaporator Tube Replacement in SI.
8. Place the evaporator tube on the bench and drill out the rivet with a ¼ in drill bit. Discard the old bracket.
9. Install the bracket kit.
10. Remove the two fasteners from the bracket and install them on the evaporator tube.



11. Snug up the lower bolt on the bracket.
12. Attach the bracket to the fastener and tighten the bolts.

Tighten
Tighten the bolts to 9 N·m (80 lb in).

13. Inspect the tighten the two bolts that retains the thermal expansion valve.

Tighten
Tighten the bolts to 16 N·m (12 lb ft).

14. Install the evaporator tube. Refer to Evaporator Tube Replacement in SI.

Example of How to Attach Bracket to Wiper Transmission Assembly Bracket (shown without evaporator tube)




15. Attach the evaporator tube bracket to the wiper transmission assembly bracket and tighten all bolts.



16. On LNF turbo-equipped models, install a plastic tie strap around the surge tank outlet hose and attach it to the threaded hole in the rear of the cylinder head.
17. Install the wiper transmission assembly. Refer to Wiper Transmission Replacement in SI.
18. Install the pencil brace.
19. Install the hood release cable to the pencil brace and, if vehicle is equipped with an automatic transmission, install the breather tube.
20. Install the air inlet grille. Refer to Air Inlet Grille Panel Replacement in SI.
21. Install the left and right wiper arms. Refer to Wiper Arm Replacement in SI.

For vehicle repaired under warranty, use: