HELP weird noise at start up
#1
MBWorld Fanatic!
Thread Starter
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; 05-15-2015 at 10:08 PM.
#2
Senior Member
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; 05-14-2015 at 05:58 PM.
#3
MBWorld Fanatic!
Thread Starter
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
#5
MBWorld Fanatic!
Thread Starter
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
Trending Topics
#8
Senior Member
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 :/
#9
MBWorld Fanatic!
Thread Starter
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 :/
#10
Senior Member
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.
#11
MBWorld Fanatic!
Thread Starter
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?
#13
Member
Join Date: Nov 2014
Location: Central Pennsylvania
Posts: 138
Likes: 0
Received 2 Likes
on
2 Posts
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!
#14
MBWorld Fanatic!
Thread Starter
#15
Senior Member
#16
MBWorld Fanatic!
Thread Starter
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
#17
Member
Join Date: Nov 2014
Location: Central Pennsylvania
Posts: 138
Likes: 0
Received 2 Likes
on
2 Posts
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.
#18
Senior Member
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.
#19
MBWorld Fanatic!
Thread Starter
hum i made another video ill post it now its getting louder each day
#23
MBWorld Fanatic!
Thread Starter
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
#24
Member
Join Date: Nov 2014
Location: Central Pennsylvania
Posts: 138
Likes: 0
Received 2 Likes
on
2 Posts
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)?
#25
MBWorld Fanatic!
Thread Starter
ya it defiantly is coming from the motor i have my appointment Wednesday ill find out 100% what it is then