Hum noise when turning left...??? 2007 ML
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2007 ML 350 - VIN 4JGBB86E17A211020
Hum noise when turning left...??? 2007 ML
Greetings all...
At 100K on our 2007 ML we had the power steering pump replaced as it was leaking. Ever since the pump was replaced by the dealer it appears to produce a low frequency hum/whirr when turning left and less so when turning right.
It occurs at mid/high range of speed...non-existent at low speeds.
Its not the same squeal noise as when the power steering fluid runs low; I checked that and it appears OK. Tires were rotated yesterday but the noise is still there.
Makes me think its related to transmission but that assumption doesn't seem correct as the tranny should be indifferent to turning the car.
It doesn't inhibit driving but it is a mystery to me where this noise is coming from.
Any insights welcome....
Happy holidays
At 100K on our 2007 ML we had the power steering pump replaced as it was leaking. Ever since the pump was replaced by the dealer it appears to produce a low frequency hum/whirr when turning left and less so when turning right.
It occurs at mid/high range of speed...non-existent at low speeds.
Its not the same squeal noise as when the power steering fluid runs low; I checked that and it appears OK. Tires were rotated yesterday but the noise is still there.
Makes me think its related to transmission but that assumption doesn't seem correct as the tranny should be indifferent to turning the car.
It doesn't inhibit driving but it is a mystery to me where this noise is coming from.
Any insights welcome....
Happy holidays
MBWorld Fanatic!
Joined: Feb 2005
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From: North Carolina
98 Black C43 , 12’ ML 350 Blutec
How many miles do you have on your tires? I had the same noise and just recently had my tires rotated and the noise diminished considerably.I have about 35k on my tires and its common to expect more road noise from tires near the end of their life.
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2007 ML 350 - VIN 4JGBB86E17A211020
Could be the tires...
I have about the same (35K) mileage on my Michelins...so maybe the power steering hypothesis is wrong.
When my tires were rotated this week I did notice the overall noise diminished a lot...but its still there. Makes me think that even after rotation the left side of one of the tires is worn and is causing the noise.
That would make sense given the noise occurs at med to high speeds and increases in volume the higher the speed.
My fear is one of the all wheel drive train components is starting to fail...but that would show up at all speeds.
Would welcome others to comment....
When my tires were rotated this week I did notice the overall noise diminished a lot...but its still there. Makes me think that even after rotation the left side of one of the tires is worn and is causing the noise.
That would make sense given the noise occurs at med to high speeds and increases in volume the higher the speed.
My fear is one of the all wheel drive train components is starting to fail...but that would show up at all speeds.
Would welcome others to comment....
MBWorld Fanatic!
Joined: Feb 2005
Posts: 5,761
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From: North Carolina
98 Black C43 , 12’ ML 350 Blutec
I have about the same (35K) mileage on my Michelins...so maybe the power steering hypothesis is wrong.
When my tires were rotated this week I did notice the overall noise diminished a lot...but its still there. Makes me think that even after rotation the left side of one of the tires is worn and is causing the noise.
That would make sense given the noise occurs at med to high speeds and increases in volume the higher the speed.
My fear is one of the all wheel drive train components is starting to fail...but that would show up at all speeds.
Would welcome others to comment....
When my tires were rotated this week I did notice the overall noise diminished a lot...but its still there. Makes me think that even after rotation the left side of one of the tires is worn and is causing the noise.
That would make sense given the noise occurs at med to high speeds and increases in volume the higher the speed.
My fear is one of the all wheel drive train components is starting to fail...but that would show up at all speeds.
Would welcome others to comment....
I agree with everything you say and I was thinking the exact same thing.I am due for tires in about 2 months ( I average about 500 miles a week ).I'll post the results when I get the new tires .
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2006 ml350
I had a similar noise from our 2006 ML350 with just under 75,000 miles. A "hum noise", as my wife described it, from the drivers front that diminished when turning right and got louder when turning left. I though it sounded more like a propeller driven airplane; the noise got louder with increased speed.
The noise was the passenger side front wheel bearing and it got louder when loaded (turn left) and quieter when unloaded (turn right). The wheel bearing was replaced by the dealer at no charge under the extended warranty. Therefore, I have no idea what the dealer cost was or how difficult it is to replace. I have replaced this style of bearing on other front wheel drive vehicles and the job is more tedious than complicated.
Good luck on the diagnosis and repair...
The noise was the passenger side front wheel bearing and it got louder when loaded (turn left) and quieter when unloaded (turn right). The wheel bearing was replaced by the dealer at no charge under the extended warranty. Therefore, I have no idea what the dealer cost was or how difficult it is to replace. I have replaced this style of bearing on other front wheel drive vehicles and the job is more tedious than complicated.
Good luck on the diagnosis and repair...
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2007 ML 350 - VIN 4JGBB86E17A211020
Could be a wheel bearing
Exactly the same condition....louder on left turns., quiet on right turns, increase with speed.
Just to double check...was it the passenger front side? That would make sense as the wheel is unloaded in a left hand turn
No warranty so I will have the dealer check that.
Just to double check...was it the passenger front side? That would make sense as the wheel is unloaded in a left hand turn
No warranty so I will have the dealer check that.
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2006 ml350
Yes, it was the passenger front wheel bearing.
If you put the vehicle up on a lift (all four wheels need to be off the ground) and had the vehicle in gear you could hear the noise clearly and we were able to isolate it to the passenger front. With the engine off and the vehicle out of gear you could rotate the wheel/hub assembly by hand; but no noise or "roughness" could be felt. The proof was that the noise was gone after the bearing/nub assembly was replaced.
Please note that the wheel bearing comes as a hub assembly that includes not only the bearing, but also the speed sensors that input to the cruise control, ESP and ABS.
If you put the vehicle up on a lift (all four wheels need to be off the ground) and had the vehicle in gear you could hear the noise clearly and we were able to isolate it to the passenger front. With the engine off and the vehicle out of gear you could rotate the wheel/hub assembly by hand; but no noise or "roughness" could be felt. The proof was that the noise was gone after the bearing/nub assembly was replaced.
Please note that the wheel bearing comes as a hub assembly that includes not only the bearing, but also the speed sensors that input to the cruise control, ESP and ABS.
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MBWorld Fanatic!
Joined: Feb 2005
Posts: 5,761
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From: North Carolina
98 Black C43 , 12’ ML 350 Blutec
Yes, it was the passenger front wheel bearing.
If you put the vehicle up on a lift (all four wheels need to be off the ground) and had the vehicle in gear you could hear the noise clearly and we were able to isolate it to the passenger front. With the engine off and the vehicle out of gear you could rotate the wheel/hub assembly by hand; but no noise or "roughness" could be felt. The proof was that the noise was gone after the bearing/nub assembly was replaced.
Please note that the wheel bearing comes as a hub assembly that includes not only the bearing, but also the speed sensors that input to the cruise control, ESP and ABS.
If you put the vehicle up on a lift (all four wheels need to be off the ground) and had the vehicle in gear you could hear the noise clearly and we were able to isolate it to the passenger front. With the engine off and the vehicle out of gear you could rotate the wheel/hub assembly by hand; but no noise or "roughness" could be felt. The proof was that the noise was gone after the bearing/nub assembly was replaced.
Please note that the wheel bearing comes as a hub assembly that includes not only the bearing, but also the speed sensors that input to the cruise control, ESP and ABS.
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2006 ml350
As I stated in a previous post my replacement was covered under the extended warranty....
But I have from a fairly reliable source that the front wheel bearing is around $90.00 and 2.4 hours labor to replace. That does not include any diagnostic time or incidental line item charges that some shops include.
But I have from a fairly reliable source that the front wheel bearing is around $90.00 and 2.4 hours labor to replace. That does not include any diagnostic time or incidental line item charges that some shops include.
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2007 ML 350 - VIN 4JGBB86E17A211020
That jives with my call to the dealer
They said the bearing could be replaced without replacing the hub...so off it goes to the dealer for replacement.
BTW the sound and feel is very similar to when I had bearings go bad on my old 1979 RX-7...hard to believe I can remember that far back...
BTW the sound and feel is very similar to when I had bearings go bad on my old 1979 RX-7...hard to believe I can remember that far back...
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2007 ML 350 - VIN 4JGBB86E17A211020
It was the left wheel bearing - $811
Guess even though I got an A in college physics I called this one wrong 
Took the 2007 ML 350 in for the humming noise when turning left. I thought it was the right wheel bearing that was howling when accepting additional g forces when turning left. It turned out to the left wheel bearing that would howl when unloaded; the tech heard it immediately when he spun both wheels on the rack.
Even though the bearing was $126, the cost was $811 to replace as they have to disassemble the wheel unit; calipers, rotor, etc.
So back on the road it goes....seems like a common failure point at 100K for MLs...odd that my 1991 190 has not had this problem. Maybe it uses wheel bearings from an ME-109... :0
Thanks MBworld for the steer...
Took the 2007 ML 350 in for the humming noise when turning left. I thought it was the right wheel bearing that was howling when accepting additional g forces when turning left. It turned out to the left wheel bearing that would howl when unloaded; the tech heard it immediately when he spun both wheels on the rack.
Even though the bearing was $126, the cost was $811 to replace as they have to disassemble the wheel unit; calipers, rotor, etc.
So back on the road it goes....seems like a common failure point at 100K for MLs...odd that my 1991 190 has not had this problem. Maybe it uses wheel bearings from an ME-109... :0
Thanks MBworld for the steer...
