Potentially Bad Strut/ Front end Creak and Pop over bumps

struts
noises
mercedes-benz
m-class

#1

Hi,

Thanks for taking the time to read this.
I have a 2010 ML350 Blutec that i bought at 80K miles. I had the front control arms replaced and still have significant poping/creaking over bumps in the front end. The mechanics inspected everything in the front end around the control arm, and since replacing the control arm is a fairly invasive procedure, one would think they would spot a problem if it was in an associated component. The pop existed before and after that procedure, and now i think that it is related to the strut.

  • The sound only happens when going over speedbumps, potholes.
    *Sounds like CREEEAK POP Creeak POP…pop
  • No sounds from turning the wheel.
  • No fluid leaks around the strut/ ride is level
  • Sometimes on the highway, bumps take a while to settle out (but it doesn’t seem excessive)

I’ve attached a picture of a worn segment on the loudest side (Driver front) and would like to know if you guys think this is the cause, or if this type of wear is normal. Mechanics charge quite a bit just to look at things, so the input is greatly appreciated.

Also, If the strut is bad:

  • What other problems can it lead to if not replaced immediately (If its just noise i can live with it)
  • How long can I wait to replace it
  • If i do need to replace it, what else would be a good idea to replace at the same time?
  • What else should i check?

Thanks!


#2

That worn spot is where the dust boot rubs on the strut body. No cause for concern at all. And the rust tells me it isn’t leaking or even rubbing much at the moment. A clear indication of strut failure is oil running down the side of the strut. That is 90% of the failure of struts. They can fail internally and that my be wheat you are feeling as the car floats a bit over bumps. But the float would be noticeably different on that corner giving a roll-ey-diagonal motion to the SUV. If a strut needs to be replaced, both sides need to be done at the same time. Not all 4 just the opposite side.

The creak-pop may be coming from the spring itself even though I don’t see any issues, the strut itself, the strut bushing, the upper control arm bushings, the sway bar links or bushings. It is a tough thing to find such noises without taking it apart and checking. That’s why mechanics charge so much to “look” at things. Time is money and noises like these take time to find sometimes.


#3

The sway bar links are common wear items on front wheel vehicule. If they are failing,they will make a clunk clunk noise every time you go over bumps. To test: Grab each link and try to wiggle them. On my Toyota, they usually go bad after 3 years because of bad road condition.


#4

I’m leaning towards sway bar links and/or bushings


#5

Thanks for the detailed answer