zibby43

Continental is going to replace all 4 of my tires under warranty since it is still under 1 year since date of purchase.

They will also let me substitute for a non-RFT. I can of course look up good all-season Conti options, but if anyone has experience with a good, performance-oriented Conti all-season option, please let me know.

Hopefully this takes care of the noise from the rear and the front end’s tendency to grab the road crown and pull right with the stiff sidewalls.

stockbmw

How did you manage that? Send us your continental contact person.

zibby43

I'd be glad to share once I see they follow through with everything. Can't get into the dealer for the required write-up until July 10th.

On a side note, it is about 95 F degrees here today (ambient temperature) and very humid (heat index well over 100). Had several errands to run. First time driving my car in about a week (been using my truck instead).

Heard the noise very faintly initially when cruising in the 45-50 mph range, but after a few minutes, it disappeared. Wasn't present in either C or S+.

In my case, I've noticed that the noise seems to be temperature-related. When it's warmer, it seems to diminish or disappear. I never remember hearing the noise prior to my first oil change back in May, so I can't say what effect extreme cold had, if any.

Jujigatame

Well, I got my new tires yesterday (PS A/S 3+'s), and the noise is 100% gone.

The car rides MUCH smoother and way quieter too.

I'm very happy with the purchase!

munis

Sounds like we need bidirectional tires haha. Then we can just flip them and wear them out evenly. I have the PS4s and they are unidirectional.

zibby43

Glad to hear it.

I'm still waiting to have my tires looked at.

Took my car out for a drive again on one of the hottest days of the year so far (92 F with heat index values in the 100 degree+ range) and again, in the hot weather conditions, the noise was NOT present.

Jujigatame

If that's the case, I'd bet it's almost definitely the tires.

I can't believe how happy I am with the Michelins.

I changed the pressure to what Michelin recommends for the car and it has made all the difference. I'd bet that the fully laden pressure that MB recommends is one of the major factors to the tires wearing out so fast.

The car feels amazing and is so quiet.

jonathan358

Over inflated tires tend to wear less.

zibby43

Could be. Very peculiar. My warm PSI ends up being about 38-39 (F) and 37-38 (R) on these hot days . . . about 2-3 PSI higher than the recommended 36 F; 35 R for sedans equipped with all-season RFTs and 18" wheels.

Regardless, I'm glad switching to non-RFTs has helped your issue. With the amount of camber these cars have on the rear tires, it basically pitches the inside shoulders toward the road surface, which cannot be good for either noise levels or ride quality when you have super-stiff sidewalls.

Has there ever been ANY other AMG car that has come with runflat tires, prior to the C43?

On a side note, earlier in the thread, someone said a technician said that the noise was the result of the Performance Exhaust hardware and cold weather. I have the PE, and I don't seem to hear the noise in hot weather. In my case, I think it has to be 1 of these 2 issues.

Seanhfx

UPDATE: Took the car back to the dealer and they finally diagnosed the whinning noise to be the differential. They put it up on the hoist and the noise was very noticeable whilenot under load. It will be replaced under warranty in 2 weeks.

The conditions I outlined in 1st post is the kicker here folks, very specific with no throttle while coasting during specific speeds. I suspect if the whine happens to you under those conditions as GWSHARK outlined, it's the differential, not the tires and certainly not wheel bearings. A noise with the tires would be very different sound under different conditions, same with the wheel bearings so if you have a whine pitch that is loudest just around 80-85km/h while coasting from 90km/h, then take it in. It's louder in the colder weather as the noise travels more but still happens in hot weather (30c+), but is not as pronounced and is not as noticeable from 90 km/h to 78 km/h.

Seanhfx

I replaced the RF @ 2,500 kms, now at 16,000 with the AS 3+ and tire pressure being 36F, 33 R when cold. Yes they rise to 41F, 37R when hot. What does Michelin recommend and where does it say it?

munis

Guys, I figured mine one out. It was the tires.

zibby43

Just an update for my situation: It's definitely not the tires.

The noise seems to disappear completely in hot ambient conditions (85 F or above). Haven't heard it in a week.

Tonight, driving home in cool conditions (74 F), I heard the noise while traveling at 50 mph. My noise is most pronounced while I'm lightly applying the throttle to maintain speed. When I remove my foot from the throttle, the noise disappears or becomes so faint that it's hardly perceptible. In other words, the noise I experience happens when I'm *not* coasting.

It's like high-pitched whistling noise, as opposed to a mechanical whine (which is why I'm ruling out the diff. in my case). Can only hear it if I have the radio turned off.

Definitely coming from behind me. Could this be exhaust related? Something to do with the PE?

Jujigatame

www.michelinman.com

Put in your car and it'll recommend tires and pressure:

Jujigatame

Not necessarily.

When the pressure is increased beyond the recommended pressure, the contact patch of the tire actually shrinks. The increased pressure usually causes the center of the tread to protrude further out than the rest of the tire tread. This is a problem because now the majority of the tire’s traction is coming from only the center of the tire, reducing the overall contact patch of the entire vehicle. With our cars being highly cambered and the runflats stiff sidewalls, it seems that it would cause the majority of the wear on the inside (which, coincidentally, is what most of us have experienced).

Seanhfx

Yeah that doesn't sound right....says to use 39/39 PSI. That is WAY to high for the rears.

zibby43

Temperatures were cooler here today. In cooler temperatures, I'm usually able to notice the noise. In the past, I've pretty much always driven the car with the PE on, even in C.

Today, I drove with the PE off in C. First off, I couldn't believe how quiet and docile the car was (which I was impressed by). Second, no noise on or off throttle at the speed I usually hear it.

Car is scheduled to go up on the lift on August 5th, just to completely evaluate/rule out the diff and go from there.

TModelle

Maybe sound processor for the PE through the speakers?

zibby43

Can you tell me more about this?

I can't believe that in the few months I was trying to diagnose the noise, I never tested to see whether the noise went away with the PE off. I was so preoccupied with the diff.

TModelle

Is yours a 2019 Facelift model, or 2018 and earlier pre-FL model?

zibby43

2018 model.

TModelle

In that case, try taking out the engine noise sound generator fuse in the trunk fuse box.

Bananamani

Hello everyone, new 2017 c43 owner here (one month), just noticed the "whirling noise" while coasting and letting off the gas, also the AC blowers are extremely loud with quite noticeably Steering vibration when AC is on full blast (7). Got an appointment for tomorrow at 4, will mention the differential since I believe this could be the culprit from all the posts here. As for the AC, maybe a bad blower?

Seanhfx

Well my problem seems to be resolved with the diff being replaced yesterday. Drove about 150 kms and no noise that is noticeable when I did the coasting test between 90km/h to 78km/h.

Good luck all.

zibby43

Very interesting. I'll try that. Really appreciate the info! I was unaware that engine noise was pumped into the cabin with the 2018 cars equipped with the PE.

Do you have any technical information where I can read up more on it, or a diagram?

That's great news. Glad to hear it, Sean. Thanks for all the updates and for taking the time to answer questions. My car is getting the lift test on August 5th.

Does the noise start when you let off the throttle, or when you are on the throttle to maintain speed?