mint

In my never ending saga of eliminating problems in my car, I'm asking for a comprehensive list from the W208 experts of things that I could check for my two issues below...anything would help at this point as these are driving me nuts and I'm getting desperate to the point where I want to ram my car into a wall. I just love her too much to bring myself to do it.

1.) Low speed front driver's side vibration that can be felt in floorpan and behind pedals. At 65mph, steering wheel shimmies and vibration in floorpan increases. 70mph the steering wheel ceases to shimmy to any noticeable degree. Steering shock has been recently replaced, tires and wheels road force balanced on a Hunter GSP9700 three times by three different shops, all balance out okay. Low speed vibration makes me think it's something steering or suspension related, not wheel/tire combo (I have this issue with both OEM and aftermarket wheels). Fire away with any and all suggestions, no matter how obvious or insignificant they seem.

2.) When idling, slight shake to the car. I just had the two motor mounts and tranny mount replaced and it might be me, but the vibration seems a tad worse. Also, whether loaded or unloaded I can feel a cyclic vibration in the shifter so I don't know if perhaps these are related or not. Other than having the mounts rechecked, what else can I have them check in the engine or driveline to squelch all drivetrain vibrations? Again, anything you can think of would be greatly appreciated.

MarcusF

To see if the ball joints are dead, raise the wheel check for vertical play when pushed from the bottom. Just grab the wheel at 12 and 6 o’clock and see if there’s any play. If not, but there is play at 9 and 3 o’clock, that might be bearings. Of course, it could be the tie rods too.

So, what happens if

The ball joints are bad? Camber wear and clunking noise
The tie rods are bad? Feathered tire wear
Worn bearings Loud noise at speed and steering wander.

The steering gear bolts are tight, right? I don't think they would cause anything like what you're describing, but it takes five minutes.

One thing you want to make 100% sure is not the issue - and I mean find out quick:
The flex discs are OK, right? If the front disc were to let go at speed, the results could be horrific. I've seen photos where the tail shaft of the transmission was destroyed and the floorboard had been sliced open - all because $100 flex disc came apart. AND THEY DO CAUSE VIBRATIONS WHEN GOING BAD.

mint

Ball joints: checked and said to be tight (no clunking anyways)
Tie rod ends: I really feel like these could be the culprit + the drag link but I've been told they're all tight
Wheel bearings: possible...but no roaring/whining and I'll have them checked
Flex discs: Again, told they're okay but I'll have the shop recheck.

To start us off, I'll make a list I have so far of possible causes for both my issues and you guys can add if there's something missing or subtract if it can be eliminated:

- Inner/outer tie rod ends + drag link, ball joints, wheel bearings
- Lower control arm bushings
- Hub out of spec, rotor out of spec
- Possibly mismounted spring/spring pad/bolt/fastener after installing Eibachs
- Worn shocks
- Motor mount/tranny mount
- Flex discs, center support bearing, driveshaft balance
- Plugs/wires

That's all I can think of. Anything I'm missing or doesn't belong on this list?

mint

New Bilstein shocks helped a ton. Eliminated most of the vibration and the car feels a lot tighter in turns and going over bumps. I'm guessing the residual (mostly in the floorpan) is drivetrain-related or possibly lower control arm bushings.

When I have the dealer recheck the motor/tranny mounts, I'll make 'em look at the flex discs and center support bearing as well. I did check for bearing/ball joint/tie rod play and couldn't feel anything terribly noticeable, thus my deduction to it being the bushings.

mint

Agh, I spoke too soon. Don't think the shake and steering wheel shimmy ever left me.

I'm 95% sure it's not the wheel/tire combo as it's obviously intermittent. What specific front suspension components should I be looking at that can cause intermittent vibes at highway speed? Note that I'm also fairly certain this is isolated to the driver's front side. Could defective Eibach springs cause this?

U.S

Have you tried to change wheels, rear to front or left to right.
Tires can do a lot of these vibrations.

AUDIO GUY

Have the same vibration at idle problems on mine. My local indie got a faulty crank position sensor code on the diagnostic. Being fixed as we speak (hopefully).

mint

If you mean due to the tire tread design, I suppose that's possible (not sure if a Hunter would be able to pick up something like this); I should do a switch on the fronts. I would find it hard to believe that between about 6 or 7 wheels swaps between OEM and aftermarket wheels, I always pick the one wheel with the worst force variance but my luck is pretty terrible so who knows. Also, my highway shimmy is pretty intermittent so I'm starting to feel it's more suspension related but I haven't forgotten about tires and wheels yet!

Ironically, mine seems like it got worse after the dealer fixed a leaking valve cover gasket and replaced my motor and tranny mounts. I don't think CPS is likely but since they'll need to recheck their work and more drivetrain parts, I'll have them check codes.

mint

I think next up on my list is to install the KMAC kit which will rule out worn control arm bushings. Then also going to install a new OEM tie rod assembly (all 4 tie rods plus drag link). Somewhat certain it's one of these items causing my problem. Also, to fix my uneven lowering I'm going to have the mechanic loosen all the lower control arm bolts front and back, preload the suspension, then tighten them down.

Hopefully that fixes the front end problem -- fingers crossed.

AMG_BENZ

How much does the bill for the repair at the dealer cost? How many miles is your car?

mint

For what specifically? KMAC bushings and tie rod assy are being done at an indy suspension specialist.

I currently have about 93,xxx on the clock.

SINEWAVE101

HAVE 2008 CKL 350 CONVERT. HAVE HAD CAR IN MANY TIMES TO DEALER IN FLORIDA WITH NO RESOLVE.CALLED BENZ IN NJ
NEW TIRES, BALANCED AND ALIGNED FRONT, NEW MOTOR MOUNTS, NEW TRANS MOUNTS, AND NO RESOLVE

ANS:
THE 350 CLK CONVERT HAS A VIBRATION PROBLEM THAT ACCORGING TO BENZ HQ. IS AN UNRESOLVED PROBLEM. I HAVE STEERING WHEEL WOBBLE
WHICH IS ACCENTUATED BY BREAKING.

I AM HAVING A HELL OF A TIME RESOLVING THIS AND THE CAR IS UNDER WARR AND WAS CERT PRE OWNED WHEN BOUGHT IN 2/2011.

WHAT A MESS THEY SOLD A CAR TO ME WITH A ANNOYING PROB THAT CANNOT BE REMEDIED>

SO ANNOYING TO DRIVE-FEELS LIKE YOU ARE IN A MASSAGE CHAIR ALL THE TIME
I WANT THE CAR RETURNED AND REFUND. ILL LET EVERYONE KNOW!

MarcusF

Sounds like bad rotors. Hard to envision someone saying they couldn't figure that out though. Nice to hear the mounts were covered.

SINEWAVE101

HAD CAR BACK TO MERCEDES DUE TO WHEEL WOBBLE OR OSCILLATION OF STEERING WHEEL.

NO RESOLVE AT ALL

CAR AHS 34K MILES AND IS A GREAT LOOKER BUT PIA TO DRIVE

WOULD LOVE TO SOLVE PROBLEM

BENZ HQ ESSENTIALLY TOLD ME TO TAKE A WALK.

?????????????ROTORS??? ANY SUGGESTIONS???

AN INDEPENDENT ANALYSIS BUT WHERE IN SOUTH FLORIDA???

I WAS TOLD THAT THIS IS A PROB WITH CLK CABRIOS AND NO KNOWN RESOLVE- HARD TO ACCEPT???????????????

THIS IS MY 14TH BENZ!!!!!!!!!!!!!!

SINEWAVE101

ANY BENZ MECANICS READ THIS PROBLEM I WOULD LOVE A REPLY AT
SINEWAVE101@AOL.COM

THANKS ALOT
SINEWAVE

Mercee

My 99 cab has the same problem. Every time I balance the wheels it helps but never completely goes away. Sad to hear this may be an unsolvable problem ;(

SINEWAVE101

I AM GOING TO FIND OUT WHO AT NJ OFFICE TOLD MY DEALERSHIP THAT IT WAS AN UNRESOLVABLE PROBLEM AND THEN I WILL CONSULT WITH A ATTY TO SEE IF WE CAN CREAT A CLASS ACTION ???

IT BEHOOVES ME HOW AN ORGANIZATION CAN CERFIFY AN AUTO AND NOT DISCLOSE PROBLEMS THAT CANNOT BE REMEDIED

LR

mint

Sinewave - this is the 208 forum so you'd probably be better off in the 209 section. Also, please stop locking caps.

I actually decided against installing the KMAC kit as I don't want to do anything to make the ride rougher. The ride has been with the dealer since Friday morning getting service B done along with a ton of work covered by my service contract. If anything relevant comes up regarding my issues, I'll update.

mheffel

Over the years I've had vibration/shimmy problems, and the biggest culprit on my car was the tires. I've had several kinds on the car, but whether they were cheap or expensive if I rotated them they gave me problems such as shimmying, noise, wheel hop, and trammelling ... just an all around bad ride. Made me feel like I wanted to just give the car away.

Solution - Don't rotate your tires. Your tires won't wear out any faster, you'll save yourself time and money, and have a smoother ride. Everything else should be right too though - tire inflation should be by the book; lug bolts should be torqued correctly and in a criss-cross order, etc.

LAWYER2

Haven't read through the entire post but, FWIW my cab has crazy vibration around 60 mph, that won't go away till about 75 mph. I've been meaning to get the wheels balanced as a first step.

mint

After a service B, nothing was really solved other than maybe my idle vibe (probably due to cylinders 1, 3 and 5 partially misfiring - plugs and wires).

As far as the low speed grinding/rubbing feeling in the floorpan, nothing. Should I just start throwing parts at the car? Wheel bearings, tie rod assembly, etc.?

I've already had Bilstein sport shocks put in along with a new steering damper. Car is currently at 95k.

LAWYER2

from what everyone is articulating, it sounds like this is something that is a by-product of the cabriolet and (un)fixable! If you figure it out, please share with the rest of us

mint

Are you referring to cowl shake? Because cowl shake occurs due to the chassis flexing and resonating at a harmonic order. What I'm describing occurs at 3mph+ primarily through the floorboard and is a grinding/rubbing feeling, not a resonating vibration through the chassis*.

*I do get 55mph+ vibration, but I'm chalking it up to crap tires and crap balancing jobs. Front wheels road force tested 4lbs and 24lbs, rears tested something insane like 38lbs and 45lbs

Mercee

for anybody experiencing that ~60 mph vibration, try over inflating your front tires 5-10% it has pulled some of the shake out of mine

OzC36

Engine harmonic balancer starting to come apart? There was an MB recall on some part numbers.