A/C Compressor
A/C Compressor
Section titled “A/C Compressor”The E46 uses a Denso or Behr A/C compressor driven by the serpentine belt.
Part Number
Section titled “Part Number”64 52 6 918 751 (Denso OEM)
Specifications
Section titled “Specifications”- Refrigerant: R134a
- System capacity: 750g (26.5 oz)
- PAG oil: 135ml PAG 46
Signs of Failure
Section titled “Signs of Failure”- No cold air
- Compressor clutch not engaging
- Unusual noise from compressor
- Clutch slipping
Diagnosis
Section titled “Diagnosis”- Check if compressor clutch engages when A/C is turned on
- If clutch doesn’t engage: Check fuse, relay, pressure switch, and clutch gap
- If clutch engages but no cold air: Check refrigerant charge
- Metallic noise: Internal compressor failure — requires replacement
When replacing a compressor, also replace the receiver/drier and flush the system.