Big Whining Sound
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 349
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
Big Whining Sound
Hey team. It's cold up here in Toronto. So maybe that has to do with it. But Over the last two weeks the ML has a large pitch whining sound from the engine bay.
It's not the power steering pump cause when at a stop I turn the wheel everything is ok. But under acceleration and even deceleration the whining sound is evident.
The lights everywhere look fine and don't dim at all. Is it possibly the bearing in the alternator about to fail?
Thanks in advance for your help.
It's not the power steering pump cause when at a stop I turn the wheel everything is ok. But under acceleration and even deceleration the whining sound is evident.
The lights everywhere look fine and don't dim at all. Is it possibly the bearing in the alternator about to fail?
Thanks in advance for your help.
Senior Member
Joined: Oct 2023
Posts: 473
Likes: 241
From: New Hampshire
ML 63 AMG
Originally Posted by OUZO Power;[url=tel:9104328
9104328[/url]]Hey team. It's cold up here in Toronto. So maybe that has to do with it. But Over the last two weeks the ML has a large pitch whining sound from the engine bay.
It's not the power steering pump cause when at a stop I turn the wheel everything is ok. But under acceleration and even deceleration the whining sound is evident.
The lights everywhere look fine and don't dim at all. Is it possibly the bearing in the alternator about to fail?
Thanks in advance for your help.
It's not the power steering pump cause when at a stop I turn the wheel everything is ok. But under acceleration and even deceleration the whining sound is evident.
The lights everywhere look fine and don't dim at all. Is it possibly the bearing in the alternator about to fail?
Thanks in advance for your help.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 349
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
Senior Member
Joined: Oct 2023
Posts: 473
Likes: 241
From: New Hampshire
ML 63 AMG
Originally Posted by OUZO Power;[url=tel:9104743
9104743[/url]]Ah yes. There is that possibility too. Thank you. Guess I just keep monitoring things till it gets worse to have a better idea what is the casue.
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Joined: Jan 2016
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From: In the Shadow of the Tetons
2013 ML350 Bluetec
Anything the serpentine belt touches is suspect. Take the belt off and start spinning everything the belt is routed over and around; you'll find your answer in the one that isn't silent.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 349
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
MBWorld Fanatic!
Joined: Jun 2014
Posts: 1,086
Likes: 443
From: Melbourne, Australia
2010 ML550 VIN WDC1641722A564750, 2010 B180
You haven't said what engine you have. I'm assuming its the gas V6 ot V8.
In addition to the other suggestions, check for blow-by at the oil filler cap. If it seems excessive, then you might have a clogged up PCV rebreather valve. They have a centrifugal rotor that spins and separates the motor oil from the exhaust fumes. They block up and cause an almighty whining sound. It's located on the back of the head on the RHS (from driver view) and is encases in a black plastic fan shaped cover. These are a maintenance item.
In addition to the other suggestions, check for blow-by at the oil filler cap. If it seems excessive, then you might have a clogged up PCV rebreather valve. They have a centrifugal rotor that spins and separates the motor oil from the exhaust fumes. They block up and cause an almighty whining sound. It's located on the back of the head on the RHS (from driver view) and is encases in a black plastic fan shaped cover. These are a maintenance item.
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MBWorld Fanatic!
Joined: Jun 2014
Posts: 1,086
Likes: 443
From: Melbourne, Australia
2010 ML550 VIN WDC1641722A564750, 2010 B180
Further to my previous post, increase the rpm to the level that creates to noise and then loosen the oil filler cap just enough to release any pressure and so it doesn’t cover you in oil. If the noise stops, its most likely the pcv valve as described earlier.
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Joined: Apr 2007
Posts: 436
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Former R230, W220 and W221 owner
You haven't said what engine you have. I'm assuming its the gas V6 ot V8.
In addition to the other suggestions, check for blow-by at the oil filler cap. If it seems excessive, then you might have a clogged up PCV rebreather valve. They have a centrifugal rotor that spins and separates the motor oil from the exhaust fumes. They block up and cause an almighty whining sound. It's located on the back of the head on the RHS (from driver view) and is encases in a black plastic fan shaped cover. These are a maintenance item.
In addition to the other suggestions, check for blow-by at the oil filler cap. If it seems excessive, then you might have a clogged up PCV rebreather valve. They have a centrifugal rotor that spins and separates the motor oil from the exhaust fumes. They block up and cause an almighty whining sound. It's located on the back of the head on the RHS (from driver view) and is encases in a black plastic fan shaped cover. These are a maintenance item.
and for reference, here is the video intsructions. I did it over the summer myself.
USE GENUINE PARTS. DO NOT BUY THIS OFF AMAZON ETC...
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 349
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
You haven't said what engine you have. I'm assuming its the gas V6 ot V8.
In addition to the other suggestions, check for blow-by at the oil filler cap. If it seems excessive, then you might have a clogged up PCV rebreather valve. They have a centrifugal rotor that spins and separates the motor oil from the exhaust fumes. They block up and cause an almighty whining sound. It's located on the back of the head on the RHS (from driver view) and is encases in a black plastic fan shaped cover. These are a maintenance item.
In addition to the other suggestions, check for blow-by at the oil filler cap. If it seems excessive, then you might have a clogged up PCV rebreather valve. They have a centrifugal rotor that spins and separates the motor oil from the exhaust fumes. They block up and cause an almighty whining sound. It's located on the back of the head on the RHS (from driver view) and is encases in a black plastic fan shaped cover. These are a maintenance item.
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 349
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
and for reference, here is the video intsructions. I did it over the summer myself.
USE GENUINE PARTS. DO NOT BUY THIS OFF AMAZON ETC...
https://www.youtube.com/watch?v=G4fv0i_OhOg
USE GENUINE PARTS. DO NOT BUY THIS OFF AMAZON ETC...
https://www.youtube.com/watch?v=G4fv0i_OhOg
Thread Starter
Senior Member
Joined: Mar 2015
Posts: 349
Likes: 47
From: Brooklin, Ontario
JGC SRT, ML 550, GLB 250
So a quick update on this. I was wrong. I assumed cause there was no whining when I turned the wheel it had nothing to do with the power steering.
So guess what. The fluid was low. Discovered a leak from the reservoir. I've replaced it before a few years ago. Topped it off and whining sound went away. Now I have to wait again for the weather to warm up and replace it once more. What is PITA is mines the V8. Little to no room to swap it out.
So guess what. The fluid was low. Discovered a leak from the reservoir. I've replaced it before a few years ago. Topped it off and whining sound went away. Now I have to wait again for the weather to warm up and replace it once more. What is PITA is mines the V8. Little to no room to swap it out.
