The symptoms indicated you may need replace the air compressor:
1: Lower ride height or sagging suspension
2: Abnormal sounds during compressor operation
3: The compressor doesn’t run at all

Application:

Compatible for Compatible for Audi A6 C5 4B Allroad (2001-2005)

Compatible for Audi C5 4B Allroad quattro  (1999-2005)

Reference OE/OEM Number:

4Z7616007, 4Z7616007A, 4Z7 616 007,4Z7 616 007 A

compatible for Relay OE

8K0951253, 8D0951253A, 4H0951253A

8D0 951 253,8K0 951 2534,4H0 951 253 A,H0 951 253 A

Specification:

Condition: New

Fitment Type: Direct Replacement

Quantity:  1pc Air Compressor Pump+1pc Relay

Placement on Vehicle:   Front, Rear, Left, Right

Warranty: two years warranty for any manufacture defect

Greasable or Sealed: Sealed

Length, width and height : 32*21*20cm（12.3*8.3*7.9inch）

Weight: 4.39kg

Operating Pressure : 20bar

Temperature range：‘-30℃—80℃

Amperage: <35

Voltage: DC13V

Feature:

1. Plug and play

2. 100% fully tested

3. Shipping immediately

4. Designed for a comfortable compressor and is of high quality

5. High-quality steel materials for high resilience and long service life

6. Replaces the car's original compressor,Original OE quality

7. Long-term tested (300h)

8. Suitable for operation at an ambient temperature of -30°C to 80°C

9. IP protection class: IPX4

10. Small size, easy to carry

11. Durability and safety

12. Powerful and quiet compressor

13. Easy bolt-on installation requires no modification

14. An integrated dryer removes all moisture and humidity from the air system that cause corrosion