Strange Noise

[markland]

Hi, not all the time but alot of the time, my car makes a very strange noise only when moving from the gear stick area.

listen to attached youtube recording made last summer with microphone close to gear lever.
https://youtu.be/dlIxDwZMC8k

Recently it has become a lot more frequent, can make it 'vibrate' more by depressing and lifting off the accelerator, it stops when the car comes to a complete stop.

Car has been doing this for probably 3 years and has maybe started to get louder this year and definitely gets louder on long drives.

I have put the rear of the car on axle stands and 'driven' it through the gears and revs but it doesn't do the noise and it had been making the noise all day while driving before trying it.


Car is a 2006 c180k manual saloon.

Two different mechanics have checked the handbrake cable to see if its rubbing on the propshaft and it's totally fine

Unfortunately it never seems to make the noise while on test drives with mechanics


help would be much appreciated

https://youtu.be/dlIxDwZMC8k

 

[grober]

Could be the forward flexible coupling or maybe the centre bearing support yoke.
https://www.mbclub.co.uk/forums/1605066-post8.html

 

[markland]

thank you
Is it these two parts?

 

[grober]

thank you
Is it these two parts?

Yes those would the parts in question.

Other possibility might be a weak or misaligned rear gearbox mount. Based on the symptoms you describe its got to be something road/gearbox output speed related. Things are rotating quite rapidly at the point you describe meaning they are sensitive to balance and alignment. By jacking up the car you have unloaded the drive train so that's maybe why you couldn't elicit the noise - no torque transmission??

 

[markland]

thanks, have edited the video down to make it more understandable what the noise is, the end of the video is the car coming to a complete stop https://youtu.be/JF_KqoxnsVk