Air suspension is a critical component that directly affects ride smoothness and vehicle handling. In models like the Mercedes-Benz W220, the compressor plays a central role: it pumps air into the air springs and maintains the specified ride height. When suspension issues arise, the first step is to figure out how to check the compressor to identify the root cause.

How to Recognize a Malfunction

Before starting diagnostics, it is useful to know the symptoms indicating incorrect operation of the device. Typical signs include:
  • the body starts to sag at one or more wheels;
  • after a long period of parking, the vehicle drops almost to the ground;
  • the suspension operates with jerks or the lift is too slow;
  • the compressor activates too often or refuses to start altogether;
  • unusual noises or vibrations are heard during operation.
These signs are especially characteristic of the Mercedes-Benz W220, where the air system reacts sharply to wear and increased loads.

Ways to Check the Compressor

You can perform diagnostics using several methods without visiting a service center.

Inspection and Listening

Start with a visual inspection and sound assessment. When the ignition is turned on and the suspension is activated, the compressor should start smoothly without harsh noises. Clicks, whistles, or heavy humming indicate overload or wear of the mechanism.

Pressure Measurement

The device must generate sufficient pressure to fill the air springs. By connecting a pressure gauge to the outlet port, you can compare the readings with standard values. Low pressure indicates either a loss of compressor power or an air leak in the system.

Leak Detection

Even a working compressor cannot lift the vehicle if air escapes. To find leaks, treat connections and hoses with a soap solution—bubbles will indicate the problem area.

Electrical Check

It is equally important to ensure the power supply is functioning. Use a multimeter to check fuses, relays, and voltage at the terminals. If power is present but the compressor does not start, it will need repair or replacement.

Specifics of Checking the Compressor on the W220

The Mercedes-Benz W220 has its own nuances. The compressor is located under the hood, and access is not always easy. During diagnostics, pay attention to the following:
  • Operating duration. If the device runs for more than 30–40 seconds but the body does not rise, efficiency is reduced.
  • Heating. Under overload, the compressor heats up quickly and may shut off due to the temperature sensor—this is a clear sign of wear.
  • Start frequency. In a healthy system, the compressor activates rarely. Almost constant operation signals leaks or wear.
  • Scanner diagnostics. For the W220, diagnostic equipment (e.g., Star Diagnosis) can be connected to read air suspension fault codes.

What to Do in Case of a Breakdown

If the check reveals unstable operation, there are several solutions:
  • replace the filter and dryer if the cause is moisture or contamination;
  • eliminate leaks in hoses and air springs;
  • clean or repair the compressor itself;
  • if significantly worn, install a new unit.
For the Mercedes-Benz W220, it is better to choose original parts or proven alternatives—cheap components fail quickly.

Conclusion

Now it is clear how to check the air suspension compressor. The main steps include visual inspection, pressure control, leak detection, and checking the electrical part. W220 owners should especially monitor the compressor's operating time and overheating. Timely diagnostics will extend the life of the air system and avoid costly repairs.