Loud whining sound from engine bay
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2012 GL550
Loud whining sound from engine bay
I've had this loud whining sound come up a couple times already. It sounds like a mix between a whining whirling sound. Almost like the supercharger wind sound. It happened three times when it was cold and i started it up for the first time in the morning. It went away after i turned off the car and started it back up. This happened a few weeks ago. I thought it was just related to starting the car up on a cold day. Today, after parking in an underground garage for like 10 hours, i started the car and drove to another parking lot a few blocks away and parked, opened the door and noticed that the same whining sound was going. I turned the car off, turned it back on and everything was normal again. Any idea what this noise is?
It whines changes in frequency? pitch? when I rev the car. I couldn't isolate the noise to the exact location because I turned off the car right away again.... but it is from the front of the car.
A similar thread regarding this sound....but I heard it even after i drove for about 5-10 mins.
https://mbworld.org/forums/showthrea...t=engine+whine
Another thing I just noticed since I had the radio totally off. Do you guys usually hear the brake light switch click when you step on the brake pedal gradually and when you let go of the pedal gradually?
It whines changes in frequency? pitch? when I rev the car. I couldn't isolate the noise to the exact location because I turned off the car right away again.... but it is from the front of the car.
A similar thread regarding this sound....but I heard it even after i drove for about 5-10 mins.
https://mbworld.org/forums/showthrea...t=engine+whine
Another thing I just noticed since I had the radio totally off. Do you guys usually hear the brake light switch click when you step on the brake pedal gradually and when you let go of the pedal gradually?
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From: San Francisco, CA
2002 C32
I've got the same noise in my 2002 C32 (early production, made in 2001). How long have you had yours? I've had mine for two months (bought it used). If you've had yours longer, has this problem recently came up or was it always there and you never noticed it? My car is at the dealer right now and I mentioned this as one of the problems I have but they said that it may be a vacuum pump of some sort simply recharging or the exhaust purge valves. Regardless, I said that it doesn't sound right and it's not always present but when it is, it is very noticeable. I can even hear it on the highway going 80mph. They said that they'd have a tech listen to the engine and make sure that everything that makes noise should be and nothing should be out of the ordinary. I'll report back tomorrow. I'm hoping it isn't something more serious. But if it is, I'd be glad that they at least did something about it. The noise that I hear is definitely coming from the driver's door and is noticeable even with the window up so it's definitely coming somewhere from the drivers side. It could be either inside the driver's front fender or right underneath the driver.
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2012 GL550
The noise I am hearing isn't quite from that side of the car. It sounds like the very front of the car. I haven't taken it to the dealer because it happened only a few times, weeks apart and I know even if I drop the car off to the dealer for a few days, they would never hear it.
I also bought the car used, so I am kind of sensitive about sounds, since I'm not familiar with how everything should sound, like when the car was brand new.
If it does happen again (I'm not sure when, might be awhile), I will try to isolate the exact location the sound is coming from.
I also bought the car used, so I am kind of sensitive about sounds, since I'm not familiar with how everything should sound, like when the car was brand new.
If it does happen again (I'm not sure when, might be awhile), I will try to isolate the exact location the sound is coming from.
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From: Switzerland
C 32 AMG (203.065)
Originally Posted by bnz616
The noise I am hearing isn't quite from that side of the car. It sounds like the very front of the car. I haven't taken it to the dealer because it happened only a few times, weeks apart and I know even if I drop the car off to the dealer for a few days, they would never hear it.
I also bought the car used, so I am kind of sensitive about sounds, since I'm not familiar with how everything should sound, like when the car was brand new.
If it does happen again (I'm not sure when, might be awhile), I will try to isolate the exact location the sound is coming from.
I also bought the car used, so I am kind of sensitive about sounds, since I'm not familiar with how everything should sound, like when the car was brand new.
If it does happen again (I'm not sure when, might be awhile), I will try to isolate the exact location the sound is coming from.
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From: San Francisco, CA
2002 C32
MadC32, what did the air pump control? Curious if it's something critical to the operation of the car. On mine, it's a whirring noise and the noise varies with different throttle pressure.
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C32 AMG
bnz616: This is common problem on W203s. The noise you hear is a dying secondary air injection pump. It's function is to reduce cold start emissions, this is why you hear at cold start up.
Take the car to dealer, they should be aware of this problem and get it fixed within a day.
Good Luck!
Take the car to dealer, they should be aware of this problem and get it fixed within a day.
Good Luck!
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2012 GL550
Does this secondary air injection pump actually cause any large problems when it starts to fail? I can't repeat the noise for the dealer, so I'm guessing the service advisor is going to give me the excuse that theres nothing wrong. Maybe I might have to wait until it does it more often?
Vader13, is the smog pump the same one as the one stated above? "secondary air injection pump"
xqwizit, do you still hear the sound when you start driving? does it always have the noise now?
Thanks guys. When the noise comes up again, I will check for the source of the noise near the foglights.
Vader13, is the smog pump the same one as the one stated above? "secondary air injection pump"
xqwizit, do you still hear the sound when you start driving? does it always have the noise now?
Thanks guys. When the noise comes up again, I will check for the source of the noise near the foglights.
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From: San Francisco, CA
2002 C32
bnz616, yes, I intermittently hear the noise when I'm driving (even on the highway). The noise seems to vary with different throttle pressure. Sometimes I can hear it, sometimes it's not there. It's hard to reproduce but I know it's coming from the driver's side of the car.
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From: Switzerland
C 32 AMG (203.065)
could be called the smog pump, all I know it's purpose is to lower emissons.
It's really no big deal.. can't cause an engine failure or something. It really just is here to lower the smog emissions.
It's really no big deal.. can't cause an engine failure or something. It really just is here to lower the smog emissions.
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From: Irvine, California
C32 AMG
Originally Posted by IdriveFast
i took my car in for service today for the noise you guys are describing. I hope I dont get my car back tomorrow with them saying "we couldnt find out what was wrong" 
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2012 GL550
The squealing noise came back again tonite. Was parked outside for about 10 hours....probably around 55 degrees outside. I checked for where the noise was coming from, it wasn't behind the foglight. It came from directly center front, so I popped open the hood and listened to where it was coming from. It sounds like its coming from right under the mb badge on the engine cover. I peeked under there and there are some small pulleys. Does anybody know what the pulleys directly under the engine cover (right under the mb badge on the cover) do? What do they belong to?
I turned off the car for about 30 secs and turned it back on and it went away. I drove home and parked the car inside the garage. The squealing noise apparently came back while I was driving home. I turned off the car again and it went away....don't hear it anymore. It's annoying me because I know I won't be able to replicate the noise for the dealer to hear.
I turned off the car for about 30 secs and turned it back on and it went away. I drove home and parked the car inside the garage. The squealing noise apparently came back while I was driving home. I turned off the car again and it went away....don't hear it anymore. It's annoying me because I know I won't be able to replicate the noise for the dealer to hear.
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2012 GL550
The squeal doesn't come up all the time, which is why I'm thinking the dealer might not hear it and will dismiss the problem. Is this noise normal? and is it even a problem? What is a possible solution?
Thanks.
Thanks.
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2012 GL550
Originally Posted by MadC32
When I had this problem, I had to replace my air pump. Wouldnt shop whining until I pulled the plug on that thing..
What happens if I disconnect the pump? How does this secondary air pump / pollution pump work anyways? Will it affect anything if I disconnect it until I get a chance to bring the car in?
Last edited by bnz616; Apr 27, 2005 at 06:26 PM.
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From: North Cuba/West Bimini
Cars and boats!
i have a noticalbe whining sound comming from under my hood but it seems that as the sound becomes louder my butt and back get pushed further back into my seat.... :p
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From: Bloomfield Hills, MI
W203, W211, W219, W212
Originally Posted by BenzoAMGpower
i have a noticalbe whining sound comming from under my hood but it seems that as the sound becomes louder my butt and back get pushed further back into my seat.... :p
I've been having the same problem .. I'll take it to the dealer tomorrow.
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From: North Cuba/West Bimini
Cars and boats!
Originally Posted by 360_iti
r u sure it didn't come from your BACK seat ? :p
.
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From: Phoenix Arizona
2005 C55 AMG
I had the same thing happen in my 02 C32. I did the same thing, I unplugged the pump, but I did mine over night while my car sat in the garage, then the next day I plugged it back in and it worked fine for a few weeks. Then I took it to the dealership for some other work and I mentioned the problem that I had and they told me it was a bad relay switch on the smog pump (pollution pump, air pump, whatever they want to call it 
). The overnight unplug I did may have let the electronics reset because it did work fine after that but the switch did need changing. And yeah, it took the MB mechanic about .5 hr.
). The overnight unplug I did may have let the electronics reset because it did work fine after that but the switch did need changing. And yeah, it took the MB mechanic about .5 hr.
