Tyre or bearing noise - The garage indicates tyre noise.

[SilentSpanner]

Greetings, everyone.
Recently, I traveled from Nottingham to Wales for business. As my car's air conditioning was inoperative, I intermittently opened the window to get fresh air.

Operated the vehicle at a velocity between 70 and 90.
Upon closing the windows, I noticed a buzzing noise that intensified with speed, which I suspected may be attributed to the wheel bearings.
The mechanic inspected the vehicle and confirmed that the bearings are functioning properly. However, the rear tires are producing noise, despite having acceptable tread depth, which is attributed to their inferior quality.

This pertains to the 2007 W211 E220 model, which has accumulated 180,000 kilometers.
Front tires - Pirelli - Cinturato (exceeding 5 years in age, however retaining substantial tread depth)
Replace both rear tires - Dynamo (installed in mid-2021, although the vehicle has only been driven 10,000 miles since) - the tread is also highly effective in this regard

I detected tire noise according to the road type, but I disregarded it since it was not very bothersome.
Recently, the rear shock absorbers were replaced (non-2024), and during a lengthy work-related trip, I noticed a significant amount of humming sounds.

I conducted an online search for similar sounds.

The rear tires are expected to last at least 40,000 miles; however, mine had worn out after just 10,000 km.
The rear shock absorber has also been modified lately.

What are your opinions on this noise?
Additionally, how can I accurately ascertain which tires are producing the noise?

Thank you for your assistance.

[Lemmand]

Diagnosing wheel bearings may be challenging. Noise is often present without play, which worsens when roughness is perceived, followed by further deterioration and eventually observable play.
During the journey, upon hearing the humming sound, gently engage the brakes, accelerate, and maneuver away from the straight path. Should the loudness alter during any of those operations, it is probable that a wheel bearing is deteriorating. Which one thereafter poses the difficulty!

[Maidaser]

A deteriorating wheel bearing often produces increased noise when subjected to lateral forces, such as during turns. I anticipate that the "garage guy" from whom you sought help is knowledgeable about this and that it informed his reasoning for attributing it to tire noise.

Diagnosing the source of sounds online is often ineffective; however, if you are confused about the reason, see a professional who can examine the bearings and identify the source of the noise.

[Carishme]

I had a same issue with a 944 that I transported to the South of France many years ago, around the period when Jesus was a fullback for Jerusalem.

I brought it to the local tire expert who said, "It's the tires!"


However, the tires seemed to be in acceptable condition.

Upon our return to the UK, it became evident that the tires had flattened or warped due to prolonged stationary positioning.

It may be beneficial to explore this issue, since the vehicle has barely accumulated 10,000 miles over four years. Was it stationary for an extended duration?

Potential solution? Purchase a set of rear tires and wheels on eBay, replace them, and assess any resultant differences. They can always be resold on eBay.

[Istairde]

Exchange the front wheels with the rear ones and observe any alterations in the noise, or alternatively, raise the tire pressures by 20 psi to see whether the noise dissipates or manifests at different velocities. Merely a contemplation

[SilentSpanner]

It is accurate that it has not been driven much, accumulating barely 10,000 km over four years.

The garage personnel are generally reliable, yet end customers like us inevitably have some skepticism over their judgment.


Reading about various concerns on the internet may indeed be intimidating. I am willing to attempt shifting the tires and wheels to assess the outcome.

[Maidaser]

Annual payments of $2,500 for four years are often feasible and typical for many; however, complications arise if the mileage is almost nil in a single year.

[depofly]

You can consider repairing the air conditioning; this would eliminate the need of opening the windows