MBNUT1

I am perplexed by the highway ride quality of my E. First of all it is not clear whether the problem is my expectations or the quality of the ride. The issue is on what appears to be smooth pavement (ie no visible bumps) I will experience a vibration that could possibly best be described as a light tremor. Now let me explain further that there are times when the ride is perfectly smooth. It is a those moments that the car is heaven to drive. And because I can sustain periods of perfect smoothness I am tending to rule out tire imbalance as the vibrational source. It is as though if there is a slight uneveness in the road surface it will excite some sort of vibrational mode in the suspension. And this is where the perception part gets into it. For all I know the ride would be worse with another car and the Mercedes is just struggling to filter out the imperfections, but it doesn't feel that way but rather as I have described about as a vibrational mode that is excited by slight road imperfections. Any thoughts? Thanks in advance.

konigstiger

Even though you do not mention a knocking/rattling noise, it may very well be the front shocks
https://mbworld.org/forums/3166666-post1.html

Polar Bear

Also could be tires. Have you had your tires rotated lately?

These things are hard to track down but are not always what they seem.

MBNUT1

Thanks Konigstiger. I have heard what sounds more like a bushing squeak when I have gone over speed bumps in the past. Bad shocks could explain it thought the shocks would have to be bad in a very unique way. That being no damping for small amplitude oscillations but good for larger ones. This is possible but I don't know if it correlates to the issue that you referenced.

MBNUT1

I will have that done tomorrow and I will have them check the balance as I'm sure that that is the first thing that the dealer will want to do. The tires are new (5k miles) Michelin MXM's. I agree that these are very difficult to track down.

One thing I was hoping to get from the board is what other folks ride experience has been. This would help me sort out if it is me in terms of my expectations or the car. I can safely say that the way the car rides is definitely consistant with my expectations of a Mercedes. On a couple of occasions it has definitely vibrated unacceptably but later rode smooth as silk.

Polar Bear

I have seem similar results with mine. I am not sure if it has to do with tire temperature or what. I have noticed my car drives better with more pressure in the tires than recommended. I run 40lbs in my car and like the drive much better. It has 16" wheels and is a CDI.

My tires are almost new but were on the car when I purchased it. It felt like a tire was out of balance when I purchased it so I requested the dealer balance them. When I got the car back it drove unchanged and also pulled to one side. I then went to a tire shop and requested the tires be re-balanced and rotated and it drove perfect when I got the car back. On the contrary, during my next routine service, I requested the tires be rotated once again. When they were rotated, the car pulled to the side again and also had the vibration again. I have come to the conclusion I have a warped wheel or a faulty tire but do not know which. About one week after this, I requested the tires be rotated once again (back to where they were when the car drove well), and the problem went away and the car drives smooth again (I assume the problem wheel/tire is on the rear now). Once these tires wear out (also Michelins) I will then see if I can determine the problem. Otherwise I probably will not rotate the tires anymore and let them wear.

MBNUT1

Thanks for the additional info.

konigstiger

Was unaware of new tires, then I agree GSP9700 road force balance as a starting point http://www.hunter.com/pub/product/balancer/index.htm

MBNUT1

Thanks my plan is to take it to Costco (where I bought the tires) tomorrow and have them rotate and balance the tires. The next stop after that, assuming that the problem persists, is to take it to the dealer and have them look at it. They have a road force balancer there.

steveberde

I don't know how hard you've driven your car or over what kinds of roads - but, short of some kind of damage to a wheel or some mechanical factor I seriously doubt you could have bad shocks on an 06 - It's not impossible but unlikely from my experience with three other E cars - unless yours falls under that bulletin described which your dealer can surely verify.

I have found however these cars like most high perfromance cars with great suspensions are very sensitive to proper wheel and tire balance - Speaking of Costco, I have found they sometimes are not as careful with the balance as they could be as I've had to bring my former E 420 back to them on several occasions for re balancing - they tires are also a factor on different road surfaces. Tire pressure is also a factor and while on lister said he prefers 40 pounds I've found that by using the mfr.'s suggested range you'll be happier with the ride though the wear might not be as good.

I can say that my 06 500 4matic with sport pkg. has a firm ride (which I prefer) but no road vibration and the steering is very precise.

The dealer should be most wiling to sort out anything that is out of spec for you.

Steve

MBNUT1

Thanks for the reply. I did take it to Costco and had them rotate and check the balance. They said the balance was perfect on all four tires. They set the pressure to the value on the filler door. The car rode smoothly on the way home. So we will see. It isn't a consistent problem. The vibration is similar to if you had flat spotted tires. Regarding the shock issue I did notice a distinct crunch type noise when I went over speed bumps today.