SL/R230: Loud buzzing noise, front right, behind headlight
Thread Starter
Junior Member
Joined: Nov 2020
Posts: 28
Likes: 3
From: Los Angeles, CA
1992 Ford Festiva, 2005 SL55 AMG
Loud buzzing noise, front right, behind headlight
Hello All!
Having an issue with my 2005 SL55. Car was normal, went to the store, turned off my car as usual. When I came back to the car, I noticed that my fans were still on despite the car being off for almost ten minutes. I went home and started smelling burnt electric smell. Got home, turned off my car, and heard this buzzing noise coming from the front right of the car, behind the headlight area. The noise wouldn’t go away so I unhooked the rear battery. Upon hooking it back up, the noise continued so I just unhooked it and left.
Here’s a short clip of the sound.
https://streamable.com/q3q7m2
Any ideas?
Having an issue with my 2005 SL55. Car was normal, went to the store, turned off my car as usual. When I came back to the car, I noticed that my fans were still on despite the car being off for almost ten minutes. I went home and started smelling burnt electric smell. Got home, turned off my car, and heard this buzzing noise coming from the front right of the car, behind the headlight area. The noise wouldn’t go away so I unhooked the rear battery. Upon hooking it back up, the noise continued so I just unhooked it and left.
Here’s a short clip of the sound.
https://streamable.com/q3q7m2
Any ideas?
MBWorld Fanatic!
Joined: Dec 2006
Posts: 1,308
Likes: 62
From: Bethesda, MD
2000 SL500
Sounds like it could be where the alarm siren is located? Wouldn’t explain the fans still running unless it is very hot where you are. The siren is known for failing and very common
Thread Starter
Junior Member
Joined: Nov 2020
Posts: 28
Likes: 3
From: Los Angeles, CA
1992 Ford Festiva, 2005 SL55 AMG
I’ll be trying to find the source today. Just was hoping that sound may be familiar to someone as I’ve never experienced that before. Thank you
the battery inside died overnight, that's why you don't have any noise anymore
you can just unplug the alarm next time it happens
you can live without, nothing will trigger
you can repair those most of the time, split them open, then buy a new battery pack from ebay
Super Member
Joined: Jul 2014
Posts: 992
Likes: 245
From: Tucson, AZ
'20 X5 M50i; '17 Ram 3500; Golf Cart; Bikes; Scooters
Correct me if I'm wrong, but in my 2003 SL55, the alarm is in the Left front wheel well, toward the back. Is the 2005 different?
The only obvious buzzing items in the right front are:
The only obvious buzzing items in the right front are:
- the SBC pump, which would almost certainly throw a red brake warning if it had an issue
- the intercooler pump, which is just a coolant pump motor which shuts off when the key is off
- a stuck relay in the right front SAM...possibly connected to the radiator fan
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Correct me if I'm wrong, but in my 2003 SL55, the alarm is in the Left front wheel well, toward the back. Is the 2005 different?
The only obvious buzzing items in the right front are:
The only obvious buzzing items in the right front are:
- the SBC pump, which would almost certainly throw a red brake warning if it had an issue
- the intercooler pump, which is just a coolant pump motor which shuts off when the key is off
- a stuck relay in the right front SAM...possibly connected to the radiator fan
ooops
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Thread Starter
Junior Member
Joined: Nov 2020
Posts: 28
Likes: 3
From: Los Angeles, CA
1992 Ford Festiva, 2005 SL55 AMG
Correct me if I'm wrong, but in my 2003 SL55, the alarm is in the Left front wheel well, toward the back. Is the 2005 different?
The only obvious buzzing items in the right front are:
The only obvious buzzing items in the right front are:
- the SBC pump, which would almost certainly throw a red brake warning if it had an issue
- the intercooler pump, which is just a coolant pump motor which shuts off when the key is off
- a stuck relay in the right front SAM...possibly connected to the radiator fan
I thought about it being a faulty alarm, but because it has its own battery and the noise went away when I unplugged the battery, I moved it down the list. Also, the noise was kind of weird.
Thank you, everyone!
MBWorld Fanatic!
Joined: May 2009
Posts: 1,187
Likes: 239
From: Santa Clara, Ca
2003 SL55 / 2002 SLK32
Correct me if I'm wrong, but in my 2003 SL55, the alarm is in the Left front wheel well, toward the back. Is the 2005 different?
The only obvious buzzing items in the right front are:
The only obvious buzzing items in the right front are:
- the SBC pump, which would almost certainly throw a red brake warning if it had an issue
- the intercooler pump, which is just a coolant pump motor which shuts off when the key is off
- a stuck relay in the right front SAM...possibly connected to the radiator fan
secondary air pump
heater circulation pump
windshield washer fluid pump
before listening to the audio (or gleaning from subsequent posts that there was NO red screen for SBC) I would have guessed that the burning smell was the ground connection to the SBC (there was a service bulletin/recall IIRC to improve this connection on early R230s) and that the noise was it's pump .... but now ???
an odd one for sure
Safe, Happy Holidays to all !
Chris
Last edited by latemodel21; Dec 15, 2020 at 01:13 PM.
