Intermittent vibration at very high speed S212 E63

[bolidemichael]

- 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

I don't speak with any authority here, as I run 245/45/17 - but this seems awfully high to me, particularly the fronts.

 

[sgregory124]

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

Not had occasion to yet as only had the car since the end of July. However, since I live on the border with Notts, there is one in the city centre (Nottingham) that looks a safe bet which is MB Nottingham.

 

[Steve84N]

I don't speak with any authority here, as I run 245/45/17 - but this seems awfully high to me, particularly the fronts.

If you've ever had low profile tyres you'd know they run at those higher pressures. Mine is 38F and 42R at normal speed with normal load...

 

[Neiltodd]

If you've ever had low profile tyres you'd know they run at those higher pressures. Mine is 38F and 42R at normal speed with normal load...

Mine 41 front 43 back as per merc instructions inside fuel cap

 

[Stocious]

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?

I first thought alignment and balancing

 

[bluestreak]

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.

I should have asked but at the time I did not know I had to. Acid said he can do it when I’m there next time!

 

[bluestreak]

Mine 41 front 43 back as per merc instructions inside fuel cap

how is the tyre wear at these pressures?

 

[bluestreak]

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.

i have mixed feeling regarding indie garages. I had few things done at a very well respected one. First - the battery. I asked for main battery to be replaced and with MB one specifically. All good, but only 6 months after I had “aux battery fault” - dealer diagnosed it to main battery, which I could not claim parts warranty for. Second - had front control arms replaced. Local alignment garage could not align the car. After driving car around the block alignment is off again. Chap dropped his arms saying I don’t know what’s going on here. So again, I took the car to main dealer and they aligned car properly and said something was loose there so they tightened.

A bit of a hit and miss there

 

[Hakon]

I had out of round tyres cause significant vibration on my S212 at speed before having to replace all of them. I had MB and two other places balance the wheels on a standard machine, all of whom were happy with the results !!!

Road force balancer is the only way to check this and provides a far better balance than a normal machine. It will asses the rims for trueness as well as the tyres. In some cases (not mine) the tyre can be rotated on the rim so that a better balance can be achieved. I had a previous issue with out of round the M5, also diagnosed by road force balancing.

Discout tyres Luton have a machine and are good to deal with, ask for Johnny.
Alignment, seemingly new camber bolts are required if the front suspension needs more than a jiggle and as a resuly companies are happy to pop your car on the machine but raise their hands when the camber bolt message pops up on their screens.

Simple to get the tyres road force balanced before going down other routes. Good luck.

P.S. with regards to MB, I've had absolutely zero positive experience with them. They just don't want to know and always have a reason not to do something as well as a slick answer.

 

[bluestreak]

thank you! I did not know of this method of tyre balancing! Definitely sounds like the first thing to try. Issue is that I’m currently in the middle of nowhere in Slovakia and finding one of those machine would be a challenge. But I’ll try for sure. It would be good to see if problem is solved on the way back thru Germany.

 

[grober]

My money would be on the propshaft assembly balancing. Given that the rear diff gear ratio is fixed and the engine speed / gearbox ratio are the variables the faster the road speed the faster the propshaft is turning? The propshaft is balanced as an assembly and if its ever been split [ to renew the centre bearing/mount for example] it may not have been re-assembled correctly---or its lost a balance weight --- or simply not balanced adequately for that higher speed?

 

[grober]

Propshaft Balancing / Driveshaft Balancing – Driveshaft Solutions

Using the latest technology, your single or multi-piece propshaft is dynamically balanced to an infinite degree of accuracy.

www.driveshaftsolutions.co.uk

 

[Larkone]

- 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.

You have more faith in dealers than the rest of us - I had to constantly moan at dealers about missing fixings after services on multiple company cars I had.

 

[Neiltodd]

how is the tyre wear at these pressures?

Pretty good for a 500bhp car, rears about about 14k and fronts about 16k

 

[whitenemesis]

Pretty good for a 500bhp car, rears about about 14k and fronts about 16k

You're not trying hard enough... I was lucky if I managed 9-10k from the rears on my CLS55

 

[jasonh]

I've been thinking about the problem and I really think you simply have a clip or screw loose holding an under tray somewhere. When the speed gets up it will flap.

You need to lay on the ground next to the car, reach underneath and push each bit of under tray. One bit will probably rattle because the clip has come undone.

 

[Neiltodd]

You're not trying hard enough... I was lucky if I managed 9-10k from the rears on my CLS55

Unfortunately you are probably right, I have my handbrake (wife in the passenger seat) left half on most of the time!

 

[bolidemichael]

I've been thinking about the problem and I really think you simply have a clip or screw loose holding an under tray somewhere. When the speed gets up it will flap.

You need to lay on the ground next to the car, reach underneath and push each bit of under tray. One bit will probably rattle because the clip has come undone.

Perhaps check the tie rods?

 

[leef44]

Vibration at high speed, you say?

It's your heart beat rate rising, with the exhilaration of your 600bhp going so fast at a flex of your ankle. The flapping sound effect is the resonance from the heart beat to your ears


I should be working for MB marketing...

 

[bluestreak]

Front under trays are rock solid. However driver side rear is missing a fixture!



this may or may not be it. I will have wheels balanced anyway.