C36AMGCanada

Guys,
Looking for some advice. I have had this slight vibration through the steering wheel of my C36 ever since I have owned it (+/- 18 months) and it is driving me crazy.
The vibration doesn't seem to be dependent on speed necessarily; It appears most when driving on smooth roads at about 100kmh. I have figured out it can't be a wheel balancing issue because sometimes it rides smooth as butter at 100kmh then other times its vibrating like mad, even on a freshly re-paved highway outside my house. Interestingly albeit curiously, on poor roads the vibration is less obvious.
So far I have replaced:
- Outer tie rods;
- New tires;
- New front wheels (18 inch);
- 5 x wheel balance;
- Wheel bearings;
- Steering damper / shock;
- Rotors and pads;
- Front shocks;
- Engine mounts;
- Transmission mounts;
- MAF;
- Spark plugs, coils and HT leads;
- Driveshaft flex discs.
Honestly I am completely out of ideas and different mechanics are 'unable to replicate the problem'.
Perhaps I have become ultra sensitive to the vibrations since I drive it everyday but I am becoming increasingly frustrated at a lack of completely smooth driving.
I should note that this problem exists even on my stock 17inch wheels with good tires.
The only thing I can think to try next is replacing the whole driveshaft with a used part to address any U-Joint issues as the joint is not a serviceable part.
Since this is a relatively expensive option I am reluctant to dive straight into it without seeking further advice.
PLEASE HELP!!!
Thanks
Harry

PJmak

Have you replaced the rear tires?

At this point its a control arm or a bushing issue.

I would take the car to les schwab and have them rebalance it there but dothe road force wheel balancing.

If that doesnt solve it then its not your wheels tires for sure.


Also its worth trying if the car will run without the maf sensor. That eill rule that out. They can cause vibration but not sure if at idle only. Its worth checking

C36AMGCanada

PJmak,
Firstly, thank you for your swift response it is much appreciated. I am in Canada and I am unsure what les schwab is but from my research road force balancing is pretty expensive (circa $250) and obviously I am reluctant to get this done unless I know its the wheels and tires.
Because it is happening on both my summer and winter setup I am fairly positive it is something else.
Can you shed some light on why you think it may be a control arm issue? Is it worth replacing the sway bar bushings? They seem in good shape and I am not experiencing any knocking when turning, which from my experience indicates worn control arms, although this knowledge is based off an old Honda lol.
Once again, thank you for your help.
Regards

Alex.currie44

Us Canucks have to hang in so here is some ideas.
I don't know your car but I don't see inner tierod ends but I would expect more of a shimmy in the wheel than a raw vib if it was steering related.
Having said that I just got a 2013 C63 which I had trouble getting up to speed when I test drove it a week ago in Vancouver because traffic was a ***** that day every where.
When I finally got it to speed there is a bit of a harmonic between 85 and 105 kph which I first wondered if it was a bearing because on a road bending left it got worse and bending right it goes away. I now can sense it down around 45 as well. My suspicions are that having only to move the wheel about 2 degrees to the right to make it go away there may be an alignment issue. It is going on a 4 wheel machine next week.
I also wonder why you would replace the drive shaft. If you are going to take it out why not take it to a shop that can check the balance of the shaft and put new CVs in it at the same time?
Other than that I can't offer any ideas.