Weird Clicking sound
 

2017 C3004matic, airmatic, sport pack, 19" amg wheels, approx. 1000miles

In the morning there is a clicking sound in the cabin between 25-35mph, seems to be on the passenger side. Nothing seems loose .

Weird part is the the sound goes away in about 7-10mins, so it will be difficult for me to replicate.

Any ideas?

Climate control?

what does it sound like? Where from exactly?

more info required if you want help.

Does the clicking sound happen when your are slightly turning? My 2015 w205 did and they replaced axel seals

The keyless entry will make a click click sound every now and then.

Mine did it, but it was more like a ratcheting noise, louder when turning. I heard it coming from under the car, somewhere at the end of the central console, most probably from the drive shaft. The dealer has also heard the noise. Car is in now to get it fixed.

this happened to me turning last year, they replaced my front driveshafts

Seems to be from passenger side.

Don't know exactly from where.

goes away in about 7mins , doesn't return all day even when the car has been parked for and cold.

Happens when driving straight.

This is what happened yesterday:

I drive it about once a week - it has 1100miles on it

took it out of the garage, got on to the 35mph straight road and it start above 25mph, loudest around 31mph, goes away above 35mph.
after driving for about 4 miles the sound is gone.
Car parked in office garage for 4 hours, took it out no sound. even drove the same roads (near home) no sound.
parked in office again - 4 hours later again no sound.

Will drive it again this week and try to record it.

My GLK350 makes a similar sound in the morning that I know if from the dash. Some stepper motor etc. but I got less than a year of lease on it so not going to bother with that.

The key is in my left pocket don't think that is it.

seems like its a motor or something which warms up enough after a few minutes to not make the noise any more. The speed thing is throwing me off why between 25-35mph

Mine shows the same symptoms except it's more of a ratcheting noise. Something like a revolving part rubbing against a static part. It sounds like it's coming from the passenger side, but in fact it's from underneath the car. It only happens in the morning, for a few minutes, between 30-40 mph only, sometimes it's louder on long right turns (like highway ramps) then it's gone for the day. Comes back the next morning. I suspect something around the drive shaft going from the transmission to the rear differential.
The good news is that the car is at the dealer and they have identified the noise with the pico diagnostics tool. I have yet to find out what it was.

Here's a video (not a Mercedes) that makes the same sound in the same speed range that mine makes:


If you hear the same noise from under the central console then I'm pretty sure we have identified the problem. It is (or something around) the drive shaft.

Have y'all checked the rock guard underneath the car???
If it's loose or broken, it can make that sound and then "secure itself" when it heats up and hits just the right speed.
I had a defect in my coupe, it was more of a clunk though, but it was because the entire passenger side rock guard had come loose and was banging, versus just a small section vibrating in the wind.

Just a thought.

Mine is a 2017 GLC 300 and I'm having the same problem. After driving for about 20-30 mins the car start to click but sound more like cricket when I slightly turn the car. Dealer could not reproduce sound but after pick up my car on my home i can hear it clealy.

how do I prove this to the dealer so I can get this fix?

I have recorded it with my cellphone and played it to the dealer. It sounds 100% as in the video above.

Update:

As I mentioned earlier, I had similar sound from my GLK350, slightly less sharp but stays on longer again around 30-32mph (loudest).
I recorded it and took a service apt. for the GLK350 first.

I went on a test ride with the head mechanic and we could not replicate but he watched the video and said he knew what it was.

According to him it is louder in C class and pretty much in all MBs.

He said it is the direct injection noise. apparently on a flat road, cold car I am hitting just the right parameters for the noise to be loudest.

And I was baffled as to why two different MBs and similar noise at same speeds.

Any way that is the explanation I got.

UPDATE: the Pico diagnostics tool deployed for some other issue by the dealer picked up this vibration even though no sound/noise was audible at the time and it was traced down to the drive shaft hanger bearing under the central console. Bearing replaced, noise gone!