HELP weird noise at start up
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From: London ON Canada
2012 C300 4Matic Sport Sedan
HELP weird noise at start up
Hey all In the past week or so when i start the car up when its cold it makes some weird almost computerized noise pretty loud for about 30 seconds from the drives side when i tried to record it I couldn't pick it up on my awful phone its almost a buzzing noise any idea what the heck this is? and it only happens when i start my car the first time in a day.
2012 c300 4matic sport
here is the sound
noise #2
2012 c300 4matic sport
here is the sound
noise #2
Last edited by MB Marko; May 15, 2015 at 10:08 PM.
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2016 GLE450 AMG Coupe
Could be the EIS? I always hear it after I turn my car off and sit in it for like 30 seconds. I've never heard it before or while starting my car though. :/
EDIT: Come to think of it, I do hear it before I start my car. Though it's not a buzzing noise, but more of a quick electronic sound. Like it's unlocking something.
EDIT: Come to think of it, I do hear it before I start my car. Though it's not a buzzing noise, but more of a quick electronic sound. Like it's unlocking something.
Last edited by Skyline45; May 14, 2015 at 05:58 PM.
Thread Starter
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From: London ON Canada
2012 C300 4Matic Sport Sedan
well to be honest the noise is more of a vvvvvvv(sound when you sound out v lol) up and down sounds than a buzz if that makes sense LOL i'll try to record it its pissing me off though i have not heard it before now out of nowhere it's doing it
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From: London ON Canada
2012 C300 4Matic Sport Sedan
hmm ill try and make a video tomorrow morning and post it after work maybe it will help it seems like its coming from under the hood i went out now to start it but it didnt do the noise it seems to happen once a day the first time i start the car
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2016 GLE450 AMG Coupe
Ah, yea that's a completely different sound than what I was thinking lol. I would say it sounds more like a vacuum of some kind. Mercedes used to use a lot of vacuum tubs to run components on their older models. I know this from working on my SL, but idk if they still use this tech on new cars.
Sorry I couldn't be much help man :/
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Thread Starter
MBWorld Fanatic!
Joined: Apr 2015
Posts: 1,739
Likes: 120
From: London ON Canada
2012 C300 4Matic Sport Sedan
Ah, yea that's a completely different sound than what I was thinking lol. I would say it sounds more like a vacuum of some kind. Mercedes used to use a lot of vacuum tubs to run components on their older models. I know this from working on my SL, but idk if they still use this tech on new cars.
Sorry I couldn't be much help man :/
Sorry I couldn't be much help man :/
Senior Member
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2016 GLE450 AMG Coupe
I just thought of something though. Could it bu you AUX fan? It runs on an independent system from the engine's belt. When it spins up, it's very loud and sounds kind of like that. It's the fan that's in front of your radiator.
Thread Starter
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From: London ON Canada
2012 C300 4Matic Sport Sedan
is it something I should take to the dealership to check out? i have no clue maybe in 30 min or so ill pop the hood open and see what happens when i turn it on. just wondering do other w204 drivers have the same noise?
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Joined: Nov 2014
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From: Central Pennsylvania
2013 C300 4matic Sport
To me it sounds your secondary air injection pump. It's an electric pump at the front/center of your engine. They sound similar (from what I could hear) to your video. Good luck!
Thread Starter
MBWorld Fanatic!
Joined: Apr 2015
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From: London ON Canada
2012 C300 4Matic Sport Sedan
Senior Member
Joined: May 2014
Posts: 314
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2016 GLE450 AMG Coupe
Thread Starter
MBWorld Fanatic!
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From: London ON Canada
2012 C300 4Matic Sport Sedan
well i guess i still have warranty so i might as well go to the dealer but i absolutely hate that they need to keep my car for a day/night
Member
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From: Central Pennsylvania
2013 C300 4matic Sport
If it was the sec air injection pump, they would just recommend to replace it. You could just wait and see how it goes. Worst case, it eventual dies and the check engine light comes on, then you replace the pump, fuse and relay.
Senior Member
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2016 GLE450 AMG Coupe
OH! I just remembered that the W204 had a recall on the power steering pumps for some models. Do you know if this recall was already done on your car? If not, I bet that's what it might be.
EDIT: Nvm, yours is a 2012. I believe they fixed the defect before that year.
EDIT: Nvm, yours is a 2012. I believe they fixed the defect before that year.
Thread Starter
MBWorld Fanatic!
Joined: Apr 2015
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From: London ON Canada
2012 C300 4Matic Sport Sedan
hum i made another video ill post it now its getting louder each day
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From: London ON Canada
2012 C300 4Matic Sport Sedan
so i showed them the video its long weekend so one guy was briefly there he said it sounds like the emissions pump is going but its still drivable until i get my appointment warranty better cover it lol
Member
Joined: Nov 2014
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From: Central Pennsylvania
2013 C300 4matic Sport
The air injection pump usually only runs the first 30-90 seconds after a cold startup (unless the relay gets stuck). Is that when this problem occurs? Can you tell if its coming from this motor (in the pic)?
