AMGPower88

So my friend has a 2009 C63 with 12,000 miles on it, he just recently purchased the car last month. Last week, he got Service A completed on the car and after a few days, he started up the car at cold start-up and there was a high-pitched whining noise coming from the engine, definitely not normal. He told me the car still drives fine and everything and that noise goes away after about 20 seconds after start-up. After a few hours, the check engine light came on.. So he took the car back to the dealership and telling them about that noise, kind of hinting that they caused this issue since they just serviced the car. They ran a diagnostics and they said it was throwing some very odd codes and they werent able to pinpoint the issue.

They told my friend that it had something to do with a start-up code for the engine and that they had re-programmed everything on the engine and restarted the computer. The service advisor told my friend that judging by the sound my friend described, it could be a bad air pump? But he wasnt sure, so all they did was re-program everything and the check engine light was gone. They didnt charge my friend anything and then this morning that high-pitched whine came back, but so far no check engine light on. Also if he turns off the engine and starts it again, there is no high-pitched noise, it only happens at cold start-up in the morning. So my friend is going to record that sound tomorrow morning and take it to the dealership so that they can hopefully hear it and determine what it is.

Do any of you guys have any idea what it could be? Any help would be greatly appreciated! My buddy is very worried. Thanks

CarHopper

Knowing the codes would help.

Secondary air pump could be it as well. Only used for cold starts anyways.

Wouldn't worry too much, sounds like the dealer is relatively on top of things. At least they didn't give the "we couldn't recreate the issue" shpiel

AMGPower88

Im trying to get them from my friend.

So Is this an expensive fix? Kind of weird that his car is making this strange noise right after they complete Service A..

Hopefully the dealer takes care of the issue for him..

CarHopper

The "primary" air would be your intake...

All the secondary air pump really does is pump in a little extra air on cold starts to get things going.

Not sure how much it would be to replace the pump

roadtalontsi

airpumps are about 7-800$ for the part. Its coincidence it went bad after the service. It's strange that they called the codes odd and hard to pin point. Secondary air injection only works on cold starts and the test cycle which is at idle and very random (typically when stopped at a stop light or sitting at a drive through)

AMGPower88

So right now it looks like the secondary air pump is the culprit since no other part in the engine would cause this high-pitched noise right?

CarHopper

You really can't say what it is with the information given.

Codes would help. Also a video of what the noise is. Fans, belts, pumps, and the list goes on for moving parts that can lead to a high pitch noise or squeel.

It sounds like the dealer has a decent grasp on this situation though. I'm sure some of the tech savvy guys here can listen to a video and do a search on codes and come up with a solution though. My knowledge is minimal at best.

Good luck! And get us those codes!

AMGPower88

So this is what the SA gave my friend...

M156 CODE (N3/10 IS THE CODE FOR CK ENGINE LIGHT FOR ME 97 AMG)

Any ideas..?

roadtalontsi

n3/10 is the component name for the M.E. which is the ecu or motor electronics unit. That isnt a fault code. It is normal for the secondary air pump to sound like a baby vacuum cleaner that is normal.

AMG893

Guys, i took a quick vid of my car on cold start this morning.
Is this the sound you describe? If so, this same sound happens on my ML63 and E63 also.

I was told, its an air pump, that supposedly heats up the Catalytic Converters quicker, on cold starts.

Note, i only ever get this sound on a cold start. And when i say cold start, i mean the vehicle has been sitting inside for AT LEAST 12 hours. (Oil Temp is 26Deg C)

Dont flame me, for saying it heats up the Cats, i dont know this for a fact, but its what i was told by a mechanic.

Enjoy the vid. Like & Subscribe! (LOL)

AMG893

Also, i have Star Diag, and have no error codes.

AMGPower88

But my friend said his check engine light came on, that's definitely not normal, and no it does not sound like the vacuum cleaner in the vid, its more high-pitched whine.. If it wasnt for the check engine light, we would all assume it's normal.. but the light came back on in his car after they had re-programmed and reset the computer

aussie e55

maybe its your wife she might b more confortable in the boot lol

tri-color

I have the same issue on my 2007 S600 V12, except the whining sound does not go away, it is still noticeable and gets louder when I accelerate during driving (you can hear it while sitting inside the car and it gets annoying).
MB dealer could not find the issue on my car, they changed the pumps, bunch of other unneeded **** but the issue still remains.


It is a mistery i guess.

AMGPower88

Did you get a check engine light on?

AMG893

No CEL for me

tri-color

No, I did not get the Check engine light.

Maybe there is a way to locate the source of the sound or at least the direction it is coming from?

roadtalontsi

Im not saying your friend doesnt have a problem or a check engine light. just telling you what you posted is not a fault code it is a component name. Maybe your friend's airpump is taking a crap? Who knows, post a video or something. AMG893 yes that a secondary air pump and its normal. It's because on cold start the engine runs so rich lots of unburnt fuel heats up the cats quickly, the secondary air injection - pumps air directly into the exhaust so the catalyst can dilute all the extra fuel and work properly. Tri-color post a video.

tburke123

I had a different issue, but similar sound and it took me and my mechanic a few tests to fix it. High pitched whining sound but it was when I shut the engine off... Also had the check engine light on. If still not sure what your cause is, get the PCV valve checked out. (Btw, mine went bad on an '07 ml63 at about 65k miles).

builthatch

i came here to search for this as i noticed it today. like a high pitched rustling whine on cold start up that goes away when the car gets close to temp (i assume, because when i check after a while, it's gone)

i only drive my car like once a week or so, so things like this stick out to me.

glad to see that it's normal.

mitesh26

by any chance did you find out what the issue was? i have the same problem on my 2010 c63 and its now driving me up the wall. i also have the CEL on, when i checked the error code its shows up as right bank running lean

qjumpr

Check to see if your dip stick has popped out, or loose. If so it may be the PCV valve, whistling noise is normally associated with that if you do a quick search. CEL code can be P0191 or a bunch of others including the lean bank code.

PITA to change, but its a DYI and costs about $120 for the part.

saziz

be worried. I had the same issue and one day, the car failed to start and it turned out to be the guide for the tension belt breaking off and causing major issues. Last estimate is $21K on the ML 63. I suggest you take it back to the dealer and force them to figure it out.

TaxmanHog

AMG893, thanks for that clip of a relatively normal sounding SAI pump, my wife's 2009 C300 SAI is making extremely loud high pitch/grinding noises during the cold start cycle. Looks like ours needs to be replaced. I'll capture clip of this current condition for historical record of this thread. (Good bad & Ugly of SAI pumps).


PS This in my first post to this forum, our c300 has performed perfectly for 6+ years, at some point issues arise.

uc63ry

https://www.youtube.com/watch?v=IdVZ...ature=youtu.be
(Turn up the volume. iPhone 6 didn't capture the sound that well.)

Is this the noise you are talking about?

I'm currently experiencing the same problem too (no CEL).
Has anyone solved this problem yet?

+ I also get abnormal sound when accelerating.