Hey everyone. I have a 2021 S580. Thought I'd make a post asking if anyone else has a similar noise in their car.

It's a whirring noise primarily from 10 to 20mph, happens in both 2nd and 3rd gear, and it changes frequency (the whirring becomes faster and higher pitched) and volume as speed increases. It occurs on flat surfaces, while driving straight or turning, and does not seem to change in relation to bumps in the road. I also hear it without my foot on the accelerator when coasting.

I wanted to start here with other owners who are used to a quiet car before heading to the dealer and trying to track down noises.

Thanks for reading.

 

Based on the symptoms you described—a whirring noise at 10–20 mph that increases in pitch and volume strictly with vehicle speed, occurs in multiple gears, is present while coasting, and is unaffected by bumps or steering—the most likely causes are an early-stage wheel bearing or tire-related noise, with a wheel bearing being slightly more probable. Both issues produce smooth, speed-dependent whirring that isn’t tied to engine RPM and can be most noticeable at low speeds. Less likely but still possible causes include differential or drive unit whine (especially on AWD models) or CV axle bearing wear, though those usually show changes with turning or load. Transmission, engine accessories, suspension, and brakes are unlikely given the noise characteristics. The recommended next steps are to have the wheel bearings inspected first, closely examine and possibly rotate the tires to see if the noise changes, and check differential fluid condition—particularly important if the vehicle is still under warranty.

 

I heard this in one of my previous S Class models, it wound up being the propeller shaft; there was play in the linkage when the mechanic rotated it back and forth.

 

Thanks to the both of you. I took these ideas and my own test notes and audio recording to the dealer. I'll report back, so we can have a thread in case this happens to anyone else.

 

The sound I heard was similar to a referee's whistle. Not a hard blow but the sound is similar to that.

 

I get the car back in a few days. Dealer says it's just bent wheels (the 21" wheel curse strikes again), but also won't let me pay for other smaller Mercedes OE wheels that would fit because they have to use the VIN which calls for 21" wheels. Let's say the noise is just bent wheels, my dealer-based options become fix bent wheels in perpetuity because my tire touches a leaf or sell the car.

Does anyone have experience with buying wheels off ebay and having them fitted by an independent? Will a local wheel shop do that or no since it's not their brand wheel?

 

I would not buy used wheels off eBay. Go here and get brand new, OEM wheels at great prices: https://www.alloywheelsdirect.net

I bought my AMG wheels for my SL from them and their service is excellent.

 

That sounds like the dealer.

If you look at the seller reputation off of ebay and see who the company selling is, I wouldn't have a issue buying wheels off of Ebay. We have a member here who bought 19" reproductions in the same design as the 21s and is very happy with them. Any shop that mounts tires will do it no problem. I would contact somebody who is a TireRack installer, order the tires off TireRack and have them mounted and fitted there.

The alloy wheel company Streamliner linked is excellent but they are VERY expensive. You're talking $5k for wheels vs $1k.

 

I used this company to buy ALPINA center caps for my B8 wheels. When the order arrive, they also attached documents showing how they procured the original part from ALPINA directly from Germany. This is one of very few companies that actually work directly with the same OEMs when almost all other caps I found were just chinese replicas. Would never buy something like this from ebay. Arrived in Alpina original packaging too (even the double-sided tape had Alpina logos). Very popular company on BMW forums, would definitely use this one. You always get what you pay for and I would not cheap out on something like wheels.

 

​​​​​​​How the order came...

 

Here is the link to the thread about the member who bought the reproduction 19s in the style of the 21s off eBay:

https://mbworld.org/forums/s-class-w...m_content=post

@regancc are they still working well for you?

 

I bought a set of chrome replica srt8 rims off ebay years ago. Brought the rims down to a Town Fair tire and had them mount and balance tires I bought from them. Dropped the rims off then picked up later that day. Brought them home and swapped out the wheels myself. So really the tire shop had no idea what vehicle the wheels were being installed on.

I did find a few imperfections in the chrome finish but that was actively looking 3" from the rim. Nothing you would notice just standing next to the car. For the low price I didnt complain. However the rims did get a few bends in them from hitting pot holes. I dont know if thats a good or bad thing, good as in they bent instead of cracking and breaking pieces off. Bad that they even bent. Never lost air in the tires though. Doing it over I still would have bought them.

Unfortunately I dont trust anyone else working on my car except for the MB dealer. With them I at least have faith they have the correct tools and hopefully follow the MB procedures. Cant imagine the tire shop down the street knowing how to properly align the car after looking thru the MB manual and seeing whats involved.

My last two experiences with tire shops were both negative. I had a tire pressure sensor battery die so bought a new one and drove down the street to the local small tire shop. Charged me $20 to swap it which I thought was a good price. The next weekend I went to replace sway bar links and could not get three of the wheel bolts off. They were on so tight I had to use a 3' piece of pipe over my breaker bar to crack them loose and I was using all my strength, surprised the bolts didnt break. Imagine getting a flat tire and being on the side of the road, no way to get the wheel off in that situation. No way will i take my car there again. Since then I had another sensor battery die so I swapped it out myself using a floor jack to push the tire from the rim to get my hands in there to remove/replace the sensor. Then last summer had 4 new tires installed at a Monroe Tire after buying the tires and service off Amazon. After the installation I was driving home and the ride felt extremely hard, noticed it right away thinking the tires must be solid rubber. The dash quickly lite up with tire pressure warnings. Turns out all the tires were at 50psi. Pulled over and let some air out no big deal. But its a tire shop, couldnt be bothered to simply look at the drivers door and see the correct tire pressure they should be at. Then got home and started cleaning the wheels they were filthy, they couldnt be bothered to clean up the grease I guess. Thats when i noticed they had glued two of the center caps on. The tabs were broken off and looks like they used some type of rubber or silicone glue/sealant to put them back on. They didnt even bother to inform me and instead I feel tried to hide it from me. Shady.

 

I have a great local shop that installs TireRack tires for me luckily.

 

Thanks for all the replies. Update: the whirring noise did not go away. Asked them to check CV joints, prop shaft, everything you all suggested in this thread. Not sure what they did to check, but they state the noise is not coming from the drivetrain anywhere, and said whatever noise is there, it sounds normal. They fixed the wheel bending (they said) but it doesn't feel any smoother, so I might have just given them a grand for the pleasure of driving a loaner C-Class for a week.

 

Sorry to hear that OP, well loaner became a rental instead for 1K : (

 

Years ago, I sent an email to the GM at my local dealer, saying something like this:

“Bring a $29K CLA in for service and drive off in a $29K CLA loaner. Bring a $120K S Class in for service and drive off in a $29K CLA loaner. What is wrong with this scenario? I don’t fit in the small vehicles, they are uncomfortable for me and I’m not going to drive them anymore.”

The GM phoned me and said that I had made a good point. He promised me that in the future, I would always get an E Class or better loaner.

 

My guess is its tires...frustrating!

As for loaners and not wanting to drive around in a small little car, I just ask for a specific type of car, the only time I get stuck with an A , GLA or GLB is when thats all they have and if that happens they always tell me to come back later in the day and they'll swap me into something else when something else comes back. Never been an issue. They line the loaners up on the far lane of the service drive and I just ask for whichever specific one I see there that I want. No need to be a prig about it like Streamliner lol. If I worked at the dealer and I got that call, I'd note he is always to be given a CLA lol

I actually like the C Class, they're small and zippy. I like driving something different for a few days.

 

I like my dealer and trust them with dealing with the mechanics of the car. But not the wheels and tires. On a CLS I had an annoying vibration at speed that was still there after two visits (which included repairing two bent wheels). For the heck of it, brought it to my neighborhood, family owned tire shop. They found three out of the four tires out of balance, one so badly they didn't think they could bring it in. Fixed the problem.

 

I have some curb rash from when I had the stock Pirelli tires due to what I believe was a soft sidewall and not my driving. Dealer just worked on the bends, not the refinishing, so maybe I'll kill two birds and take it to a wheel and tire place and have them check and refinish.

Not for nothing, but I got the idea from this forum for the upsized PS4S. No jinx intended, but I haven't had the blow out issue everyone was having a few years ago with 21s. Even if the noise is tires, (and for those searching later) at least the Michelins have saved me from that mess so far.

Some cars are just rough, and as I've already spent the GDP of a medium sized country on it in a year, maybe mine fits that category. I've been looking at S63 Coupes and M8s today as a potential replacement. I found a previous gen Continental GT V8 S for sale that just might be ridiculous and comfortable enough to trade for. But that's a thread topic for a different day.

 

I’m still holding out for the drivetrain. I had two MB dealerships misdiagnose until one put it in the air and hand cranked the prop shaft.

 

The P4S are not known to be quiet...does the sound change pitch at all depending on road surface or is it constant and consistent?

 

also is it only when coasting or is it when you’re throttling?

 

The road surface doesn't matter. I'm checking to see if heat has anything to do with it this week. Often I hear it after it's cold and has sat for a few hours, and I'm leaving a parking garage or parking lot, but I don't have a lot of data on if I can hear it after I drive it for awhile.

I can hear it more on throttle, because it gets louder with speed up to 20mph, but if I coast and I'm in the sweet spot, I can hear it pitch down. I'll get more data on this as well just to confirm.

Thanks for the questions. It'd be nice to be able to get to the bottom of this, so I appreciate the help.

 

If the road surface doesn’t change anything then it’s likely not the tires…

 

Update: I took it to another shop and they didn't hear any noise but said my wheels are bent, which is funny because I just paid a lot to get my wheels fixed at the other dealer. Maybe that's just the easy response to sell a service, or maybe they were bent again after one day of driving on smooth interstates. Regardless, dealer two put it up in the air, used a scope, heard nothing which means the noise is likely load dependent from the car's weight and acceleration, so that's a new thread to pull, but...

I've given up. Literally everyone I've shown hears it, except for Mercedes service mechanics, so I guess the only way to get this fixed is to wait until a part fails. In the meantime, I have a good sound system, and the volume slider still works, so unless that breaks, I'll just mask it. It honestly isnt worth my peace to deal with service departments this often when I'm not making progress.

Thanks for everyones help.