Intermittent vibration at very high speed S212 E63

[bluestreak]

It is a long shot, but I hope to get some ideas.

We are on a euro trip. Two adult and two kids. Boot full of travel things - it’s an estate. I had a chance to open E63 up on autobahn. She’s been to MSL before and pushes nearly 600bhp to the rear wheels so I thought it would be crime not to really.

I noticed two things. One is that we are still limited to 155mph, despite remap. Two - there is strange vibration from the entire car at around 110mph and up. The frequency is very similar to what you’d hear if you roll rear windows down. It sounds like something fairly large is flapping violently in the wind. This flapping window sound is a question in itself really!

The state of the car is quite good for the age. It is 2015 car and she had all front suspension components replaced (excluding springs and dampers) and engine/gearbox mounts replaced.

The vibration does feel more to do with aerodynamics than drivetrain. Sometimes you get it while accelerating. Sometimes when cruising and vibration goes away when car accelerate. It seems to depends on road surface too. The vibration frequency also changes when suspension goes into sport+ setting. Very strange.

Does any of this sound familiar to anyone here? Is there state S212 shape prone to this?

 

[Riva811]

It is a long shot, but I hope to get some ideas.

We are on a euro trip. Two adult and two kids. Boot full of travel things - it’s an estate. I had a chance to open E63 up on autobahn. She’s been to MSL before and pushes nearly 600bhp to the rear wheels so I thought it would be crime not to really.

I noticed two things. One is that we are still limited to 155mph, despite remap. Two - there is strange vibration from the entire car at around 110mph and up. The frequency is very similar to what you’d hear if you roll rear windows down. It sounds like something fairly large is flapping violently in the wind. This flapping window sound is a question in itself really!

The state of the car is quite good for the age. It is 2015 car and she had all front suspension components replaced (excluding springs and dampers) and engine/gearbox mounts replaced.

The vibration does feel more to do with aerodynamics than drivetrain. Sometimes you get it while accelerating. Sometimes when cruising and vibration goes away when car accelerate. It seems to depends on road surface too. The vibration frequency also changes when suspension goes into sport+ setting. Very strange.

Does any of this sound familiar to anyone here? Is there state S212 shape prone to this?

Remap doesnt explicitly remove the speed limit. I doubt the noise is aerodynamics related if it comes back based on road surface.

 

[bluestreak]

I am talking more about the vibration. It definitely is not linked to any particular road surface.

 

[whitenemesis]

Check all the undertrays are securely attached.

 

[Jobsworth]

I had a similar experience with my C63 w205. Whole car vibration over 140mph. I had all the wheels accurately balanced (some places will take them off the machine if the error is 5g). 5 gram error would never be felt at 70, but double the speed and I expect it will. Also AMG recommend higher pressures for high speed running - inside your fuel flap. I did address both these items at the same time, and the fault was cured so I can’t say with certainty which it was, or a combination of the two. Starting point maybe?

 

[ChipChop]

Propshaft centre bearing & mount?

 

[Deleted member 149005]

Kids squirming on the back seat?

Had you adjusted the tyre pressure for a high speed run?

 

[bolidemichael]

+1 for adjusting the tyre pressures. Once for the additional load and once again for the speeds over 130mph.

The other thing that occurred to me is the likelihood perhaps of the tyres having sat in one position for a while and developing flat spots.

 

[st13phil]

there is strange vibration from the entire car at around 110mph and up. The frequency is very similar to what you’d hear if you roll rear windows down.

My first pre-facelift W212 E63 had a whole car low frequency vibration that sounds very similar to what you describe, but that started a little faster - perhaps 125mph. Mercedes-Benz UK said, with some justification, that as they couldn't drive at those elevated speeds in the UK they were unable to conduct any diagnosis. I offered to drive back to Germany and take it to a German dealer if they arranged and paid for the diagnosis, but they wouldn't.

I ran the car on MSL's rollers right up to 150+ mph and there was no vibration, so I ruled out the drivetrain, rear tyres and roadwheels. The front tyres and roadwheels didn't appear to have any issue so, like you, I came to suspect something aero related - perhaps the undertray?

Unfortunately, I never did get to the bottom of what the cause was so can't offer a solution but the undertray is where I'd be inclined to look.

 

[SW18]

Your flappy window idea does seem like a good one. When one window is partly rolled down at speed, air is passing in and out rapidly, making that vibrating noise. Even one slightly loose bolt or slight dent on one of the various undertray parts could cause a similar noise and be undetectable until a certain speed is reached and the airflow causes the vibration to happen.

 

[bluestreak]

Thank you guys, a lot of interesting ideas!

- prop shaft bearing is something I read about too. I’m unsure how to proceed with diagnosis though.

- undertray are a possibility. This is not the first run we had and car has been to dealer couple of times. Once for service once for cooling system repair (radiator hose snapped off just before channel tunnel on the way home). I doubt they found trays loose and left them loose.

- tyre pressures, this is a controversial one. I inflated tyre to their spec according to speed and load but later found out that I wore off tyres in the middle. The whole car also felt like its riding on overinflated tires, unsurprisingly. This time we had 39psi front and 40psi rear cold. I will try couple of PSI higher and report back

- wheel balance, perhaps rear? Steering wheel does not vibrate although I do not know how 5g imbalance manifests at high speed. All I can say this vibration is not the same as one might get at 70mph after visiting questionable tyre shop.

tyres were last fitted by wheels-in-motion at north London, they seem to have a good reputation. I’m not sure which place is most accurate if not them?

 

[Riva811]

Propshaft centre bearing & mount?

i have two cars that need a new propshaft bearing and it seems to be mostly noticable when you accellerate and release the pedal to rotate freely. I could be wrong

 

[Jobsworth]

It’s not unknown for rear tyres to slip on the rim if you are in the habit of aggressive launches. Balancing obviously goes out the window then

 

[ChipChop]

i have two cars that need a new propshaft bearing and it seems to be mostly noticable when you accellerate and release the pedal to rotate freely. I could be wrong

I would assume that would be when engine load is stopped on lift off so the play in the bearing and/or mount becomes noticeable. Probably all in relation to the wear of front & rear propshaft donuts and engine mounts/ gearbox mounts.

A good indy with a pry bar required but you can check your center mount by grabbing the prop and seeing if movement is present (on an old mercedes anyway, not sure about the modern stuff)

 

[Riva811]

I would assume that would be when engine load is stopped on lift off so the play in the bearing and/or mount becomes noticeable. Probably all in relation to the wear of front & rear propshaft donuts and engine mounts/ gearbox mounts.

An good indy with a pry bar required but you can check your center mount by grabbing the prop and seeing if movement is present (on an old mercedes anyway, not sure about the modern stuff)

Indeed, my w221 needs it replacing urgently and vibrates a lot, the c216 is going off but not an emergency at this stage as per Mercedes workshop. Prices between indies and MB are nearly unnoticeable around zone 1 and zone 3 in London so I might as well go to Mercedes for it.

 

[ChipChop]

Indeed, my w221 needs it replacing urgently and vibrates a lot, the c216 is going off but not an emergency at this stage as per Mercedes workshop. Prices between indies and MB are nearly unnoticeable around zone 1 and zone 3 in London so I might as well go to Mercedes for it.

Never use main dealers except for parts but i would always favour a good independent Mercedes specialist as they have an interest in doing a good job and often are time served mechanics not just technicians. Just my opinion though.

 

[ChipChop]

It’s not unknown for rear tyres to slip on the rim if you are in the habit of aggressive launches. Balancing obviously goes out the window then

I suppose that could also "burp" some air out the rear tyres as well as putting the wheel out of balance.

 

[AMGeed]

Re the speed limiter still at 155mph, did you ask Acid or did he ask you if you wanted the limiter lifted when you had the remap?
I was specifically asked, and its now not limited at all.

Hope you get to the bottom of the vibration problem. I can't offer anything but guesses.

 

[sgregory124]

Never use main dealers except for parts but i would always favour a good independent Mercedes specialist as they have an interest in doing a good job and often are time served mechanics not just technicians. Just my opinion though.

+1 for the indies! I had a prop donut done on my old C36 years ago, can highly recommend Andy Gayle Mercedes in Oldbury for a garage that won't rip you off and do a top job. I live a little too far away from the West Midlands for him to be an option these days but just in case anyone has any requirements - he's your man! (no affiliation by the way, just a historically satisfied customer).

 

[Teego]

+1 for the indies! I had a prop donut done on my old C36 years ago, can highly recommend Andy Gayle Mercedes in Oldbury for a garage that won't rip you off and do a top job. I live a little too far away from the West Midlands for him to be an option these days but just in case anyone has any requirements - he's your man! (no affiliation by the way, just a historically satisfied customer).

I'd be interested which indy you use if you are in Derbyshire.