amg_w211

Since I bought my used W164 ML Bluetec a couple months ago, I've been dogged with excessive road noise feedback that seems to be emanating from the front driver's side of the car. Sitting as a passenger in the front, I don't hear this excessive road noise at all--again, the road noise is pronounced from the driver's seat. There's no knocking sounds when I'm driving. A few notes on the road noise:

1. Road surface. This is the most obvious item that causes the road noise.
Smooth surface (a stretch of new asphalt for instance): no road noise and very quiet; going fast or slow over this smooth surface has no effect on road noise
Regular surface: road noise is pronounced; unfortunately this is about 95% of the time; as I go faster, the road noise increases, with plateau in maximal noise around 50-55mph, then tapers off in noise at freeway speeds

2. Tires. I replaced the Bridgestone run flats (with stiff sidewalls) for new Michelin non-run flats, and they quell the sound a bit due to less road noise transmittance with softer sidewalls, but the road noise is still present (although has quieted down about 30%)

3. Recent work done. New Bilstein HD shocks, and new front lower control arm bushings (all 3). This did not quell the road noise feedback on regular road surfaces.

4. Front sway bar bushings APPEAR to be tight and the front end links APPEAR to also be tight with no apparant looseness.

5. Steering rack APPEARS to have no play and is non-mobile on the OEM original mount bushings.

6. Upper control arm bushings. They are still OEM originals.

What do you guys think this excessive road noise feedback could be? Again, it's only noise from the frond driver's side. It's sort of frustrating as I initially thought they were just the tires, but it appears to be more than I thought.

As it appears pretty easy to do, and they are relatively cheap, I may change out the front sway bar bushings. I wonder if there are bushings in the steering column that may be worn?

Any ideas/feeback on your experiences would be appreciated.

Plutoe

Have you\they checked for wheel bearing play!!

amg_w211

I had a shop check the front wheel bearings and they were determined to be tight and were purportedly smooth when turned. Also, I don't appear to get any change in noise when I quickly drive the car side to side.

Of note, I do have 1 wheel that was determined to be out of round and it may be related to the originating cause of the excessive road noise feedback, so maybe you are on to something. I'll have another shop check out the front driver's side bearings.

gaineserau

HOLY CRAP! I thought I was going crazy....I have the EXACT SAME PROBLEM!
However, mine happens most prominently at 20-40mph and sounds like a humming or something but at a constant tone! I can still hear it though at higher speeds, just not as prominently. perfect smooth pavement makes it go away. I have Airmatic so using the comfort setting VS sport on the air suspension dampens it ever-so-slightly...I have replaced tires, I have replaced brakes, I have checked ALL connections as you, I've rotated the tires after replacing them. It only comes from the front driver's side and is felt a tiny bit through the steering wheel and is almost inaudible from the front pax side! AND I REPLACED THE WHEEL BEARINGS! No change at all so don't waste your time. My 2009 ML320 Bluetec has 82K miles.

Could it possibly be the dust shield on the back of the brakes? I even went on a test drive with a mechanic who seemed to think everything was normal and that I was crazy. But it's driving me nuts.

C230 Sport Coup

Got to find a place that will run the car on a lift.
If it's not a wheel bearing, then it could be the front differential bearings
which is a common point of failure on these vehicles.
Replaced mine ~2 years ago, and no more whine.
Google mercedes ml front differential bearings.

gaineserau

Thanks much--I've read a ton about the front diff. However, there really is no whine in my car. Its a constant toned hum. I would think that if it were any sort of bearing the pitch of the noise would increase with speed? At least the tech who road with me seemed to think nothing of the diff. Plus no roughness, no grinding--it seems smooth as glass... Good tip on lift though

C230 Sport Coup

Yes, the pitch ie frequency/note of the sound increases with speed but
at low speeds and at higher speeds tends to fade or be less noticeable.
Most noticeable around 55mpg. Other issue could be transfer case.
You already replaced tires, but I once had some cheap tires, and it sounded like the rear diff (C Class on this) was about to explode but just the cheap tires. Oddly it was one of the best wearing yet with good grip tires I've ever had, ummm can't think of the name of them, Taiwanese. But wow the noise....

amg_w211

I thought I was the only crazy one but I'm also out of options as the the roadnoise feedback from the front driver's side only (near silent from front passenger seat like you). I may resort to trying some Dynamat in that engine area. Beyond either we have really sensitive ears and everyone else has the issue or we are unlucky to have this issue.

I wonder if the steering column has bushings that are worn out and transmitting more noise? I may just order some steering rack bushings (4 total) and change those for kicks.

Kennyr

Front diff bearings. Rest your hand on top of the steering wheel horn pad or airbag, on top of the column and if it's the diff bearings you will feel vibration coming through there. This is the surefire method of knowing it's your diff bearings

Kennyr

Also drain the diff and you will see a ton of metal flakes in the fluid coming out.

Astrok

Mine started the same way. Only the driver could hear it then as it keeps getting worse passengers could hear it. I just pulled mine 2 days ago and sent it to be rebuilt. It is faint but constant at first so changes in road surface and speed will change your perception of it. From the first sign to were mine got bad enough that I could not stand it any more was about 30,000 miles. At the end when I pulled it the whine/hum would start around 35 get bad to about 65 it would drown out at higher speeds wind and engine noise. Mercedes should be ashamed of the mess they made in these cars!

Kennyr

Faint low noise and vibration in steering column (not the part of the wheel your fingers touch). It was just annoying and we put up with it for 20,000 miles. I bought the complete bearing kit with seals on eBay for $300 and had a tranny shop do the whole job here in Denver. They charged me $750. Only one bearing was wiped out and I have that hanging on my wall in my garage with my other misc pictures and junk. The shop took 3 weeks because the owner got hurt and then had to attend an out of state funeral. He didn't want his other employees touching this car because they never did one and he is a perfectionist. He never saw one either but he took his time and got it right. I'm an ex mechanic with a lift and wanted no part of it. I have done diffs but that was 30 years ago. Anyway the noise is gone and there are no leaks.

Astrok

I could not fine anyone in the New York, Conn, NJ area that would do the rebuild. Had a shop in Boston area that said they would but when time came they said no. So mine as we speak is traveling cross country to a guy in Calf who re bearings them for local Mercedes dealers. So my car is sitting on jack stands in driveway and all neighbors are asking me what happen to that. Then they say glad I don't own one of them.

diamondblak05

Bad tires maybe?

jworth85

I just posted a new thread about this wind noise issue i'm having in a 2015 ML350. As soon as I get on the highway and go above 50 it sounds like a window is slightly open. It's right in my ear and it's every single time. It's driving me crazy. I bought the car used from a dealer so not sure I have much ground to stand on with Mercedes, but curious if a solution was ever found on the wind noise???

IgorE350

Have same thing with my 08 ml63amg changed bearings and tires got little better. At first i thought it went away but then i realized that it didn't.
Ordered bearings and seals for front differential. Drained the diff oil it had a lot of metal flakes and shavings, and i was surprised because i just did a oil change on my front diff about 3 months a go. so i was almost sure that my differential bearings were toast. Well took the diff out, opened it up, bearings were in top shape, minimum wear for a car with 105k miles. replaced bearings anyway and seals. Didn't do pinion bearings because they were smooth.
Time to put the differential back, got in to a problem fitting the driver side Axle in.Took the Axle in my hand and try to bend it and wiggle it to put it inside of the diff. Then notice something very interesting, CV joint that is on the differential side is super stiff, couldn't even bent it had to use 2 hands to bend it. Went to a passenger side Axle tried CV on outside, very easy, tried CV on inside, very easy to move same as driver side CV joint on the wheel side is moving smooth and free. Inside CV that goes in to the diff is stiff as what. Ordered another used Axle on ebay waiting to get it should be here by Saturday. ill put it on and update you guys if it helped.
My noise was getting loud at about 48mph and start to quiet down at about 55 ish but still good hum can be noticed. At around 50 hum was high pitch. Bottom line check your Front left Axle!

IgorE350

Yesterday got the Axle installed it. Today took the car for a ride. WOW!!! what is the difference, defiantly was my Left front Axle. I wouldn't think in a million years that it can me an Axle. I got a good used Axle and when it came i tried the joint it was very free moving very flexible. my original one was so tight i needed to use a lot of force to bend the joint.
Good luck i hope this will help someone.

jworth85

I was sure this was an air leak somewhere along the door frame. I'm also thinking its possibly coming through the hole where the seatbelt comes out of near the door. Seeing a lot of people talk about wheel and axle issues. IS that actually causing an air leak nose inside the cabin?

Anyone know if Mercedes is aware of this and have a fix?

ArcticR320

Did you solve this noise? I have the same going on in my W251 R320, year '06. Faint noise from front driver side, constant pitch. Front differential, driveaxles, wheel bearings are all concluded OK.

ArcticR320

Any luck in finding the source of this noise?

vochman

An idea on cost for front differential bearing on 2008 ML 250 W164? Indy mechanic? Thanks,

Maj. Dundee

Are you referring to the bearings in the axle? for the axle shafts? If so, approx. $25 each.

IgorE350

Had same problem loud noise at driver side at 45 to 55 mpg. i went crazy did front bearings didnt help. Then took off front left axle it seems to be tight, replaced it seem to be better but after a wile same stuff. i took off my front diff got all new bearings seals oil. same thing sounded better for a day or 2 then back to same stuff. Did rear diff oil, then rebuilt transfer case all new bearings new fluid same thing. checked front driveshaft it was ok. that noise drove me crazy. Then still brought me back to the front diff for some reason. i couldnt find Mercedes one for a good price so i got Dodge Durango with same ratio with 12k miles on it installed it and its still same noise at 45to 55 miles.
One day my Father in law came drove it and said why dont you swap the wheels from your 55 ML to this one and try.He said its tires that make that noise. I said there is no way tires can make that noise i got new Falken ZX tires on. but i was like what the heck let me try. Swap the wheels from ML55 had same rims on it but Goodyear tires on it. noise was gone went through all this work and $$$$$ and it was brand new tires made in Japan that made all that noise.
Got set of new Michelin tires and when i took it for a ride it was like i am really driving a Mercedes quiet and smooth. My problem was my brand new tires, till this day its nice quiet and smooth id say i put on 10k miles on i after that.

If its really your front diff i still have my original diff all rebuilt with all new bearings id sell for $250 shipped if interested pm me.
Btw you never said how many miles on your car?