Hey I’ve had my 2011 c63 for about 4 months now and over the last couple months whenever the car is cold and I put it into drive or reverse it has a strange vibration once the car warms up it drives smooth and still has all its power had spark plugs replaced about a month ago. Mechanic told me not to worry about it but it’s always at the back of my mind. If you want to hear the noise dm me @notorious63_

 

Check your engine mounts, I had the same problem when mine were blown.

 

did yours vibrate when accelerating because all vibrations stop for me the second I put my foot on the gas

 

You won't notice it as much or even at all when loaded in a straight line. Left corners under load could start to sound nasty depending how bad they get.

 

What is the determination for good/vs bad? Visual? Pry bar check?

when I had mine on the lift for the trans service, I felt around under there and all the gaps between the oil pan and subframe seem to be the same (no noticeable sag). The trans mount looked brand new.

Tasos was able to visually see that a mount on a customer car was shot, but I couldn’t see what he was looking at.

 

The space between the middle pan and front sway bar is a good indication.

There could be a red fluid leak stain down the body of the mount. Or they're ballooned at the bottom.

 

The good old fashioned way (vehicle in gear and smash the brake while tapping the accelerator) worked for me.

 

I’ll have to look for that next time I’m under there.

I did poke the bottom of the mount with my finger and it was pretty firm, but I have never seen a new one so I don’t know how convex that rubber needs to be to raise alarm.

No leaking hydraulic oil though.

 

This is what one of my failed ones looked like.

 

I second that, my whole car used to vibrate and I being new to the car didn’t realize my engine mounts were so far gone my engine was on metal 🤯