DamirB

Hi. Purchased recently a S600 V12 biturbo 2007. Most of issues are resolved by now and one major issue is still bothering me: when accelerating at higher speeds at about 3000-3500 rpm I hear a rattling noise coming somewhere under the middle console approximately under the cup holders/ash tray area. Some people mention a heat shirld of exhaust as a possible cause. Some point to a propshaft/drive shaft U coonector. I found on youtube one video about the U piece that may sound similar to my case. I attach the link. I also attach a video of my sound made today. I feel no vibrations at any speed. Slight vibration at 90-100 km/h only but it may be slightly unbalanced tires. Please your opinion. MB dealer told me by the way that MB has no drive shafts for V12 long version A2214109106 on stock and that it must be backordered meaning several months delivery time and 1400 euro further. They also do not sell U piece separately but only the unit as whole. On ebay is to find a second hand unit but 15-17 jear old so not sure about that option.

https://youtu.be/yiPc6rNuD98

BOTUS

didn't listen to the file - the AC low on gas makes strange noises - could turn it off and see - its free to try - till I realised its the low gas I thought the box was going wrong on my v8.... but its more strange whines and grumbles than rattles

I'm also wondering about the gearbox torque converter - the V12 puts lots of stress in the gearbox - if you exercise it

DamirB

I will check without AC. But the sound is really only appearing when i push the gas pedal doen at speeds from say 50 km/h.

I tried also with manual gear shift and kept the rpm at 3500 and the rattling was constant as long as the gas pedal was pushed. The video was made during such event.

Crito

YouTube video is just showing that u-joint is loose. It'll never move back and forth like that while driving. And you'd definitely feel vibration from an unbalanced driveshaft. Sound is coming from elsewhere...

DamirB

Thanks Botus and Crito for your valuable feedback. Will let you know when I advance my knowledge on the source of this irritated sound.

Arrie

This sound is not the same as I had but in my car the drive shaft U-joint knuckles were touching the heat shield underneath the shaft. In my case the noise appeared when I let the gas pedal go.

The center bearing is mounted to a flexible rubber sleeve and over time it weakens and sags letting the shaft drop closer to the shield. The angle at the U-joint means there are radial forces present at the bearing and these forces move the bearing and change direction based on the torque in the shaft. This makes noise appear when engine is pulling the car or when the engine is acting like a break when decelerating.

Fix for this is to pull the flimsy aluminum shield down some. It is very flexible. Then the right fix, of course, is to replace the center bearing that I also did.

For the starters you could go under the car (or your mechanic could) and pull the shield down. Your noise is very faint for the noise coming from the source I explained so you can probably fix it this way if it indeed is the shaft touching the shield.

DamirB

Thanks Arrie. To access the area and shields, do I need to remove the exhaust first? Is the exaust on the way?
Second question. Is the bearing possble to buy new and replace only that part? So no need to buy the entire drive shaft. i heard that MB is not selling individual parts as bearing, U piece, etc but only the package.

vettebk

I listened to the sound file and it sounded to me like a bad drive shaft bearing or bushing or bad flex joint connector all of which are maintenance parts on our V12s. I would get that car up in the air and do a thorough inspection of the drive line and the exhaust shields. And, of course, I could be wrong. Here is a website for you to take a look at: https://www.fcpeuro.com/Mercedes~Ben...5&b=5&d=768&v=

Keep us posted. Maybe MBWorld will let us create a data base of sounds and their ultimate resolutions; or have I been reading too much AI recently.

DamirB

I will follow up indeed your advice. Will make photos and share my feedback as soon as I do it. Thank you so much.

Arrie

I ordered the center bearing holder with the bearing included from ECS Tuning but only the holder came. I paid for the whole assembly though. I tried to contact them but no way to get any response. I then ordered the bearing from FCP Euro for about $50.

In my car (2013 S550) I did not need to remove anything for pulling the shield down. The shield is two pieces and where they join there is a screw that I could pull down. This is close to the center bearing area.

For changing the bearing the rearward portin of the exhaust pipes must be removed.

DamirB

Super clear. Yes. I read your thread and saw very useful photos there. Will keep you informed.