Mercedes-Benz steering has slight abnormal noise due to insufficient power steering fluid. Causes of abnormal noise: Insufficient power steering fluid: When the fluid level is low, steering becomes heavier and less smooth, and dry friction can cause abnormal noise. Lack of lubrication in the steering column dust cover: The dust cover is designed to prevent dust accumulation, so the surrounding area tends to gather dust. Without proper lubrication, noticeable friction noise can occur. Applying some grease usually eliminates this noise. Steering shaft sleeve detachment: Although uncommon, many Mercedes-Benz models experience steering noise due to this issue. Airbag clock spring problem: If the noise clearly comes from inside the steering wheel, it is likely caused by a faulty airbag clock spring. Suspension system issue: The suspension assembly typically consists of shock absorbers, springs, top mounts, and thrust bearings. When turning the steering wheel, the tires rotate the suspension system. Common sources of steering noise in this system are the thrust bearings and top mounts. Open the hood and listen for the noise. If it originates near the shock absorber top mount, it is likely due to a problem with the thrust bearing or top mount. Loose or damaged stabilizer bar bushings: These can cause noise not only when steering but also when driving on uneven roads. Loose bushings can be fixed by adding shims, but damaged ones must be replaced. Steering ball joint issue: Problems like wear or excessive play in the ball joint usually do not cause noise when steering while stationary. Ball joint noise typically occurs when driving over bumps. Solutions: If the noise comes from below the steering wheel, check the steering column and car floor mats. Oversized aftermarket mats may contact the steering column, causing friction noise without proper lubrication. Applying lubricant can resolve this. If the noise comes from outside the car, it might be due to insufficient lubrication in the shock absorber thrust bearing. Open the hood and listen for noise near the shock absorber top mount to confirm. If the thrust bearing lacks lubrication, apply grease. If the noise persists, replace the bearing. If the noise is not from the thrust bearing, inspect the stabilizer bar bushings for looseness or damage. Loose bushings can be fixed with shims, but damaged ones require replacement. Dirty power steering fluid increases system pressure, causing a "humming" noise from the power steering pump. Replace the fluid promptly. If the noise comes from inside the steering wheel, it is likely due to a faulty airbag clock spring. Remove the steering wheel, apply grease to the clock spring, and test. If the noise continues, replace the clock spring. Handle the steering wheel gently during disassembly or disconnect the airbag fuse to prevent accidental deployment.
