Experiencing issues with your Viano Benz air suspension can be frustrating, especially when it impacts the comfort and functionality of your vehicle. If you’re noticing your Viano sitting unevenly, hearing unusual noises from the compressor, or seeing warning lights on your dashboard, you might be facing an air suspension malfunction. This guide will walk you through common problems, troubleshooting steps, and potential solutions to get your Viano Benz back to its optimal ride height.
One common scenario, as many Viano owners encounter, is air suspension trouble arising after other vehicle maintenance. For instance, work on components like the driveshaft can sometimes inadvertently affect the delicate air suspension system. If you’ve recently had work done on your Viano and are now experiencing suspension issues, it’s crucial to investigate potential connections.
Common Causes of Viano Benz Air Suspension Failure
Several factors can contribute to air suspension problems in your Viano Benz. Understanding these common culprits can help you narrow down the source of the issue:
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Air Compressor Failure: The air compressor is the heart of the system, responsible for providing pressurized air to the airbags. Like any mechanical component, it has a lifespan and can wear out over time. High mileage Vianos, particularly those exceeding 100,000 miles (160,000 km), are more susceptible to compressor failure. Symptoms include a lack of compressor noise, slow or no response from the suspension height controls, and the vehicle sitting low.
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Fuse or Relay Issues: A blown fuse or a faulty relay in the air suspension system’s electrical circuit can cut power to the compressor and other components. This is a relatively simple issue to check and resolve. The fuse box location and layout can sometimes vary from the owner’s manual, so careful inspection is necessary.
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Air Leaks: Leaks in the air lines, airbags themselves, or valve block are a frequent cause of pressure loss. These leaks can be gradual or sudden, leading to one side of the vehicle dropping, or the entire system failing to maintain height. Listen for hissing sounds, especially around the airbags and air line connections.
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Height Sensor Malfunction: Height sensors monitor the vehicle’s ride height and provide feedback to the suspension control module. If a sensor fails or provides incorrect readings, it can lead to uneven suspension or system malfunctions.
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Control Module Problems: While less common, issues with the air suspension control module itself can also occur. This module manages the entire system, and a malfunction can result in various symptoms, including warning lights and system inoperability.
Troubleshooting Your Viano Benz Air Suspension
Before considering expensive repairs, follow these troubleshooting steps to diagnose the issue with your Viano Benz air suspension:
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Check the Fuses and Relays: Locate the fuse box related to the air suspension system. Consult your Viano owner’s manual for the specific location, although as noted earlier, the actual layout might differ slightly. Inspect the fuse for the air suspension compressor and any related relays. Replace any blown fuses with the correct amperage rating.
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Listen for the Compressor: In a normally functioning system, you should hear the air compressor engage and run periodically, especially after starting the vehicle or when the system is adjusting ride height. Listen carefully for the compressor when starting your Viano or after making height adjustments. If you hear no sound at all, compressor failure or electrical supply issues are likely suspects.
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Inspect for Air Leaks: With the engine running (or ignition on), listen for any hissing sounds around the air suspension components, particularly near the airbags at each wheel and along the air lines. You can also use soapy water sprayed on connections and lines to identify leaks by observing bubbles forming. Pay close attention to areas that may have been disturbed during recent repairs.
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Examine Height Sensors and Linkages: Visually inspect the height sensors and their linkages at each wheel. Ensure they are securely connected and not damaged. Damage to these sensors or their connecting arms can send incorrect height information to the control module.
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Check the Suspension Control Buttons: Test the air suspension height adjustment buttons, usually located in the rear cargo area of the Viano. Observe if there is any response from the suspension system when pressing these buttons and listen for the compressor engaging. If the buttons are unresponsive and the self-leveling suspension light is illuminated on the dash, it indicates a system fault.
Considering Conversion to Standard Springs
In cases of repeated or costly air suspension failures, some Viano Benz owners consider converting to a traditional coil spring suspension system. This conversion eliminates the complexity and potential maintenance of the air suspension.
Pros of Conversion:
- Reduced Maintenance: Coil springs are generally more reliable and require less maintenance than air suspension systems.
- Potentially Lower Repair Costs: Replacing air suspension components can be expensive. Conversion might be a more cost-effective long-term solution if failures are frequent.
Cons of Conversion:
- Ride Comfort Change: Air suspension is designed to provide a comfortable and smooth ride. Converting to standard springs may alter the ride quality, potentially making it firmer.
- Loss of Self-Leveling Function: You will lose the self-leveling and height adjustment features of the air suspension system.
- Potential for System Errors: The vehicle’s electronics may still detect the absence of the air suspension system and trigger warning lights, although this can sometimes be addressed with coding or modifications.
If considering conversion, ensure you obtain a parts list specifically for your Viano model (W639), as parts for older models like the W638 are not compatible. Consult with a qualified mechanic experienced in Viano Benz vehicles to discuss the suitability of conversion and ensure proper installation.
Conclusion
Diagnosing Viano Benz air suspension problems requires a systematic approach. By following these troubleshooting steps, you can identify common issues like compressor failure, leaks, or electrical faults. Remember to prioritize safety and consult a professional mechanic if you are unsure or unable to resolve the problem yourself. Addressing air suspension issues promptly will ensure the comfortable and safe operation of your Viano Benz.
