WTH? Weird noise coming from COMAND screen area - ‘20 C43
I’ve driven it about 4 times now since I observed, but I haven’t heard it sense. Do you think it settled back into place on its own?
Thank you!
I can't believe I'm only at 1,800 miles. Crazy low mileage lol. Was unseasonably warm here today (mid 80s) and with the AC cranking, no noise for a 3rd straight trip. Still curious as to what happened the day I recorded the noise, but I'll gladly let it remain a mystery so long as it doesn't return.
Very helpful. Especially in the context that this happened less than a month after I had my oil changed at the dealer (which included a cabin filter change).
I’ve driven it about 4 times now since I observed, but I haven’t heard it sense. Do you think it settled back into place on its own?
Thank you!
Plus, if you do sell, I don't know what car will you be looking at, the options are scarce. Every car out there seems to be a compromise compared to my C43 (to me at least. might not be to you)
Last edited by W205C43PFL; May 22, 2021 at 11:40 AM.
Plus, if you do sell, I don't know what car will you be looking at, the options are scarce. Every car out there seems to be a compromise compared to my C43 (to me at least. might not be to you)
That said, I’d say it’s unlikely I get rid of my C43. I am truly starting to enjoy this car now that I’m finally getting the opportunity to drive it more. The little things popping up are things I would’ve discovered a year ago, but everything has either sorted itself out or is something I could troubleshoot with no service required.
Battery issue was solved with a replacement and then subsequently utilizing the keyless go “sleep” feature. The lack of power was solved by re-adapting the transmission after the battery fault was cleared during replacement.
The mice issue was solved with a detail and some mouse traps, and should this noise come back, I’ll check out the cabin filter placement.
That said, I’d say it’s unlikely I get rid of my C43. I am truly starting to enjoy this car now that I’m finally getting the opportunity to drive it more. The little things popping up are things I would’ve discovered a year ago, but everything has either sorted itself out or is something I could troubleshoot with no service required.
Battery issue was solved with a replacement and then subsequently utilizing the keyless go “sleep” feature. The lack of power was solved by re-adapting the transmission after the battery fault was cleared during replacement.
The mice issue was solved with a detail and some mouse traps, and should this noise come back, I’ll check out the cabin filter placement.
It is a relief that you finally start to enjoy your car a little bit more, I felt bad that you kept having issues on your older one and now this newer one. Glad it is all settled now. The mice issue sure was an interesting one but either way it is all dealt with now.
Edit: I believe that our cars have a mechanical HDD, it might also be that too. Although it wouldn't be a hissing noise though.
The Best of Mercedes & AMG
I'm just very thankful it hasn't occurred again, but it's been helpful to investigate the possible causes. Have a better understanding of some of the car's systems now.
Most prominent at about 34-36 mph and goes away above that. It’s coming from the outermost vent on the passenger side, or at least that’s what it seems.
I parked at home, programmed my garage door homelink in the car, and then shut off the car. I popped the cabin air filter cover and then kind of jostled the filter housing itself (per a recommendation in the thread), but it all seemed squared away.
Went for another drive, and with all the transmission and oil temperatures warmed up, the noise could not be replicated under any circumstances.
Like the first day I noticed it, it was fairly mild outside (65 F). And like the first time, the noise isn’t present when the car is “warm.”
Most prominent at about 34-36 mph and goes away above that. It’s coming from the outermost vent on the passenger side, or at least that’s what it seems.
I parked at home, programmed my garage door homelink in the car, and then shut off the car. I popped the cabin air filter cover and then kind of jostled the filter housing itself (per a recommendation in the thread), but it all seemed squared away.
Went for another drive, and with all the transmission and oil temperatures warmed up, the noise could not be replicated under any circumstances.
Like the first day I noticed it, it was fairly mild outside (65 F). And like the first time, the noise isn’t present when the car is “warm.”
After the car warms up, it goes away. And when I drove it daily for 4 days this past week in very warm weather, it was all good.
The cabin filter didn’t seem jammed in when I checked it, and I don’t see where it could have actually accidentally contacted anything. That plus the circumstances that trigger the noise make me think it’s something else.
And amen to your post above. I’m definitely going to do my next oil change myself. Fortunately it’s very straightforward on the C43 with a few simple tools!
Just to be sure, did you check the cabin filter that is located behind the glove compartment? Nothing to see or feel there other than the access door itself. Your comment leads me to believe that you are referring to the filter that is accessible from under the hood instead.
Last edited by ////AMG_C43; May 29, 2021 at 11:31 PM.
Just to be sure, did you check the cabin filter that is located behind the glove compartment? Nothing to see or feel there other than the access door itself. Your comment leads me to believe that you are referring to the filter that is accessible from under the hood instead.
How did you gain access to the filter behind the glove compartment? Are there any existing tutorials out there, or is it pretty self-explanatory once I open it? Thanks in advance.
Edit: I'm guessing this one would work? Looks like a chore to access though! Is this filter replaced as well during the Service A?
Edit #2: After seeing the blower motor location relative to where the noise is coming from, I'm guessing that if it isn't filter-related that there may be some debris in the blower, or a bearing is going bad or something. I guess a dealer trip is imminent after all.
Last edited by zibby43; May 30, 2021 at 02:20 AM.
After the car warms up, it goes away. And when I drove it daily for 4 days this past week in very warm weather, it was all good.
The cabin filter didn’t seem jammed in when I checked it, and I don’t see where it could have actually accidentally contacted anything. That plus the circumstances that trigger the noise make me think it’s something else.
And amen to your post above. I’m definitely going to do my next oil change myself. Fortunately it’s very straightforward on the C43 with a few simple tools!
As for changing engine oil yourself, hmmm I thought you purchased PPM so you would had paid for the service anyways? Otherwise it is super easy to change oil on the C43, just need the proper socket. I still get my oil filters from the dealership while getting oil from FCPeuro (It comes with a filter but I don't use it)
Edit #2: After seeing the blower motor location relative to where the noise is coming from, I'm guessing that if it isn't filter-related that there may be some debris in the blower, or a bearing is going bad or something. I guess a dealer trip is imminent after all.
https://www.youtube.com/watch?v=ICXNLgnP83Q
Last edited by W205C43PFL; May 30, 2021 at 01:44 PM.
How did you gain access to the filter behind the glove compartment? Are there any existing tutorials out there, or is it pretty self-explanatory once I open it? Thanks in advance.
Edit: I'm guessing this one would work? Looks like a chore to access though! Is this filter replaced as well during the Service A?
Edit #2: After seeing the blower motor location relative to where the noise is coming from, I'm guessing that if it isn't filter-related that there may be some debris in the blower, or a bearing is going bad or something. I guess a dealer trip is imminent after all.
https://www.youtube.com/watch?v=ICXNLgnP83Q
https://www.mbusa.com/content/dam/mb...e_Warranty.pdf
Edit 1: My bad this isn't exactly it....
Edit 2: This should be it:
https://www.mbusa.com/vcm/MB/Digital...e_brochure.pdf
Edit 3: This as well
https://www.mbusa.com/content/dam/mb...rage_Chart.pdf
Edit 4: and this
https://www.mbusa.com/content/dam/mb...aintenance.pdf
Alternatively, you could look at the paper booklet that came with the car.
Last edited by W205C43PFL; May 30, 2021 at 01:37 PM.
Also, I had mice nest in my engine bay a few months ago. I was trying to explore every possibility to ascertain what was causing this flapping/clicking noise.
As for changing engine oil yourself, hmmm I thought you purchased PPM so you would had paid for the service anyways? Otherwise it is super easy to change oil on the C43, just need the proper socket. I still get my oil filters from the dealership while getting oil from FCPeuro (It comes with a filter but I don't use it)
Oh no, it can't be. : (
Previously, the difference between the dealership and DIY was so slim, it was more cost-effective to save the time. Now, not so much lol.
And yep, I think there’s something stuck in the blower motor. I don’t have the driver to get the two screws on the underside of the glove compartment panel to access either that filter or the blower.
How many miles on your car?
Also, I had mice nest in my engine bay a few months ago. I was trying to explore every possibility to ascertain what was causing this flapping/clicking noise.
No PPM for me. I paid for my Service A out of pocket. It’s about $100-150 more expensive than it was a few years ago for an oil change.
Previously, the difference between the dealership and DIY was so slim, it was more cost-effective to save the time. Now, not so much lol.
And yep, I think there’s something stuck in the blower motor. I don’t have the driver to get the two screws on the underside of the glove compartment panel to access either that filter or the blower.
How many miles on your car?
Speaking of blower motor, that reminds me. I had mines replaced 2 years ago because it was vibrating the whole car when fan was set to max, it was most definitely defective. I doubt yours is broken though (and I rather it isn't defective, you had been dealing with enough already)
My car is at 61,205 KMs so about 38,031 miles.
Also, I had mice nest in my engine bay a few months ago. I was trying to explore every possibility to ascertain what was causing this flapping/clicking noise.
No PPM for me. I paid for my Service A out of pocket. It’s about $100-150 more expensive than it was a few years ago for an oil change.
Previously, the difference between the dealership and DIY was so slim, it was more cost-effective to save the time. Now, not so much lol.
And yep, I think there’s something stuck in the blower motor. I don’t have the driver to get the two screws on the underside of the glove compartment panel to access either that filter or the blower.
How many miles on your car?
Speaking of blower motor, that reminds me. I had mines replaced 2 years ago because it was vibrating the whole car when fan was set to max, it was most definitely defective. I doubt yours is broken though (and I rather it isn't defective, you had been dealing with enough already)
My car is at 61,205 KMs so about 38,031 miles.
You’ve been able to give your car the mileage it deserves. Well done. Mine has been depressed in the garage lol. To be fair, I’d be at about 8-10k if I still had my PFL.
I had the engine bay professionally detailed though after I discovered it. Noise didn’t appear until after Service A.
Good news is - zero bad smells. But I’m definitely going to the dealer and will report back as to what was wrong.


You’ve been able to give your car the mileage it deserves. Well done. Mine has been depressed in the garage lol. To be fair, I’d be at about 8-10k if I still had my PFL.
lol I pray that’s not the case. The nest was abandoned when I found it. But they had put so much pink insulation on the heat sink on top of my ECU . . . who knows what else they used to build.
I had the engine bay professionally detailed though after I discovered it. Noise didn’t appear until after Service A.
Good news is - zero bad smells. But I’m definitely going to the dealer and will report back as to what was wrong.

I think I drove it less than I should be if the average annual mileage Canadians drive according to a report is 20,000 KMs which is approximately 12,427 miles.
Don't worry about the possibilities of a defective blower motor in your car. I think my car was the only one that had a defective blower motor, it is uncommon and therefore unlikely on your facelift.
Hmmm and if noise appeared after service A, probably really have to do with the filter being inserted incorrectly.




