In this brief article, we are going to discuss the different Mercedes E Class Suspension problems including AirMatic issues, what the causes are, and Troubleshooting Tips.
What are the most common suspension issues in a Mercedes E Class?
The most common Mercedes E Class suspension issues are:
- Knocking or Creaking Sounds while going over Bumps
- Vehicle Self-Steer under hard acceleration
- Corner Sagging
- Vehicle would be sitting low and unable to raise
- Squeaking Noises
- Suspension Error message
- Rear suspension Riding Lifted
E Class Suspension Set-up
The E Class first generation, launched in 1993 was the facelifted version of the W124 (originally launched in 1984). The basic Suspension set-up would be the same for subsequent generations as well. The basic set-up was :
- Front Independent double wishbone suspension with steel coil springs and gas-pressurized shock absorbers and an anti-roll bar. The upper Control Arm is a single-wishbone for all vehicles.
The Lower control arm, however, has 2 variants. For Rear Wheel Drive vehicles, the Lower control arm is 2 components with 2 ball-joint connections.
For the 4-wheel drive of ‘4Matic’ vehicles, the Lower Control arm is a Single-piece Wishbone
- Rear 5 – link arrangement with coil springs, gas-pressurized shock absorbers and an anti-roll bar.
In the W210 platform, the Estate variants (and sedans optionally) had a self-leveling rear suspension struts in parallel with Coil springs and gas-filled shock absorbers for damping along with a pressurizing pump located under bonnet.
The E55 AMG second generation, launched in 2002 was on the W211 Chassis and came with an AMG tuned Mercedes Airmatic suspension. This particular Airmatic system featured air-springs with electronic ride height control and adaptive damping at all four corners.
The Airmatic was basically meant to be a combination of adaptive damping that adjusts Damping rates continuously based on road inputs and selected driving style alongside air springs resulting in an extremely comfortable ride.
How to Deal With Suspension Problems in an E Class Mercedes?(+7 Troubleshooting Tips)
Knocking or Creaking Sounds while going over Bumps
- The front suspension makes ‘Knock’ or ‘Creak’ sounds every time the vehicle goes over even small-sized bumps on the road
- Sometimes there is dark brown oil stains on the lower control arms
Troubleshooting Knocking or Creaking Sounds
- While there are multiple reasons for Knock or Creak sounds, the most susceptible component within the suspension would be the Lower Control Arm or ‘Forward Tension Strut’ Bushing
- The Bushing has a Rubber Bushing at one end and a Ball joint at the other.
- The Control arm Bushing is “Hydraulically filled’ Rubber bushing. Generally, this part only lasts about 40K- 50K miles and mostly fails after that mileage. The dark oil stains, if any, are from the Hydraulic Fluid that escaped the bushing after it ruptured owing to wear
- While replacing the Control arm, look for a good aftermarket solution that would give more service life compared to the Rubber-Hydraulic bush.
- You could either go for a ‘Solid’ Rubber bushing or a Mono-Ball type of Bearing instead of the Rubber-Hydraulic Bush
Vehicle Self-Steer under hard acceleration
On some occasions, when driving spiritedly, you might notice that when you accelerate hard, the vehicle tends to exhibit a sort of “Torque Steer”, or in other words, the vehicle tends to steer without any steering input from the driver.
Troubleshooting Vehicle Self/Torque Steer
- Since it happens during acceleration in your Rear-wheel drive car, the source of the problem is most probably related to the rear suspension
- There seems to be Rear-Wheel Toe-Change under acceleration, which makes the vehicle tend to steer.
- Toe-change is controlled by the Rear suspension Toe-link. Hence, the condition of this link and its joints needs to be checked.
AIRMATIC System Related
- When parked for a while, one or more corners sets very low in height compared to the other corners.
- On starting the vehicle, the corner would rise, but only temporarily before sagging again.
- The car would be at an uneven height even while driving
Troubleshooting Corner Sagging
Airmatic Strut Failure
- The most probable cause would be damage to one or of the AirMatic Struts which led to a leakage and loss of air pressure.
- Therefore the particular strut was unable to maintain the required ride height
- One quick check you could do to verify that it is the Strut, is to press the ‘Axle Lift’ Button and watch how the suspension tries to raise itself.
- The Front generally goes up first in Axle-Lift. If there is a problem or leak in any one of the front Air Struts, then the suspension will either not be able to fully raise itself, or,
- The problematic Strut side will go up slightly and lower itself immediately, while the other corners are raised.
- There will also be a “Hissing’ Noise while doing Axle-Lift due to the Air Leakage
Failed Ride Height Sensor
- If the Ride Height sensor is broken, damaged or locked, it will cause the AirMatic system to get confused and not maintain ride height
Vehicle sitting low and unable to raise
- Vehicle would be sitting low generally after being parked for a while.
- Even when the ignition is turned on, the suspension would not raise itself again
- In certain cases, there would be no compressor noise
- In some cases you might get this error message,
‘AIR SUSPENSION FAILURE: VISIT WORKSHOP.’
The problem could be most likely due to an electrical fault. You should use an OBD II scanner and get it to display all the fault codes.
Troubleshooting Vehicle sitting Low
Leakages in the Air Lines
- If the suspension sits low, it mostly means that there is either ‘Low’ or ‘No’ pressure at the Air Struts
- There is a possibility of leakage at any of the connection points within the Air circuit.
- You can easily identify the points of leakage by spraying soap and water all over the entire air circuit lines and then observing for the appearance of bubbles.
AirMatic Compressor Failure
- If you find no compressor working noise, then this would most probably be the cause.
- The compressor would stop working in the following situations:
- Burn-out of the Compressor motor
- leakages in the air lines,
- airflow blockages leading to loss the of minimum pressure required to allow air suspension functioning, or
- It could happen due to either a voltage surge in the circuit or just simply due to age.
- A Bumpier than usual ride is the main symptom of this sort of failure.
Airmatic Relay Problems
- The relay opens and closes electronic circuits.
- Through this, it controls the AirMatic compressor.
- Occasionally, a relay could fail due to loads over longer periods while engaging with the compressor.
Airmatic Valve Block
- If there happens to be an AirMatic Valve block, then air can leak back into the compressor and then potentially damage the compressor itself.
- In normal driving going over uneven surfaces, the suspension makes ‘squeaking’ and ‘mild rattling’ noises
Troubleshooting Squeaking Noises
If the Airmatic Shock has failed it could lead to dislodging of internal components and subsequent squeaking noises when the vehicle runs.
Airmatic Shock Failure
An Airmatic shock could fail due to:
- A part defect
- Incorrect assembly of the suspension
- Shock has reached its end-of-life, generally the shocks last between 80K to 100K miles
Suspension Error message
- The error would generally appear as ‘STOP: VEHICLE TOO LOW’.
- This indicates that your car suspension is in a critical condition and that you should stop driving.
- In several cases the car may not even be driveable.
Troubleshooting Suspension Error Message
- The best way would be to use a Diagnostic Scanner and check for the Error Codes that the tool displays
- Whether you use a diagnostic tool or not, you would still need to do some overall checks around the entire system.
- These steps are explained in the “Troubleshooting Vehicle Sitting Low” section.
Rear suspension Riding Lifted
- The Rear suspension is at maximum Ride height at one or both then corners
- Rear suspension height does not come back to normal until the ignition is turned off.
Troubleshooting Rear suspension Riding Lifted
Two possible Causes for such a symptom:
- Rear Height Sensor is malfunctioning. If the Ride Height sensor is broken, damaged or locked, it will cause the AirMatic system to get confused and not maintain ride height
- Rear Air Spring has an issue. It is possible that the Rear Air Spring has undergone internal damage or wear
In this brief article we have discussed the different Mercedes E Class Suspension issues including AirMatic issues, what the causes are, and Troubleshooting Tips.