So our 2008 MCS Cabrio has started making some odd noises from the suspension. After sitting for a while, such as overnight in the parking lot, the first bump or two that we go over, like a speedbump or even a dip in the pavement to a drain, makes a pop/creak in the suspension. I can't tell which corner. It's not a long drawn out noise, it's a short duration noise, like something is rubbing.

Only has 24k miles on the odo.

Thoughts?

 

Look at your front strut tops for cracking. The front lower control arm bushings are failure prone, there is a test procedure for this with a video on how to. Also check your motor mounts. Next would be sway bar bushings.

 

I'm guessing a bushing failure would lead to steering wheel shake, a symptom not being found in this case (yet). By front strut tops, you mean the mushrooming problem of the hats or the actual strut itself?

 

Yes,

Check the upper strut mount or also called the guide support, you will see cracking in the rubber in a ring between the strut mount center and the metal hat.

#1 in the diagram



Guide Support / Front Strut Mount -


http://www.ecstuning.com/Search/SiteSearch/31306778833/



Or

The outer tie rods on the steering rack. You can sometimes feel it in the steering wheel at center angles , mostly when the wheel is turn all the way to the right or left and you go over a bump. They produce a knocking noise .



Tie Rod Full Section - Right Side


http://www.ecstuning.com/Search/SiteSearch/32106777522/



&

Tie Rod Full Section - Left Side


http://www.ecstuning.com/Search/SiteSearch/32116777521/




Then go to the lower control arm bushings , check the mount for cracks and the motor mount which you would feel at shift points and the engine would have more movement.

Thanks

 

Holy helpful answer batman.

I'll check this out when i get home from work.

Tips on checking rear bushings?

 

lol

Your are welcome.

Glad I could help.

 

Edited to add question.

 

The strut hat looks ok, no apparent damage. Part #3 was loose on the passenger side. I see bolt #4 is under it, should I check to see if one is loose?

Heard the noise again today while pulling into the driveway, slight lip, slow speed, left hand turn at half lock. Also heard it pulling out of a driveway, slight lip, slow speed, right hand turn at half lock. It has however happened driving straight ahead. Still can't tell front or rear.

How would i tell if it's rear swaybar bushings?

 

Part #3 is just a cap that snaps in place. Should not cause any noise. I just protects the bearing strut connection from dust and dirt.


http://www.ecstuning.com/Search/SiteSearch/31311139453/ES49917/






The nut on the top of the strut mount should be tight, unless someone replaced a strut and did not torque it down.

Do you feel anything in the steering wheel when you turn it and go over the bumps?

Might need to have someone ride in the back to see if its coming front the front or the rear. On the rear suspension they people hear noise or clunk from the rear sway bar bushings which can also be from the sway bar links.

What does the rubbing noise sound closest to?

 

Steering wheel feels fine. Noise/vibration is directly related to road quality, there is a section of brand new asphalt nearby where the steering wheel tracks perfectly straight and vibration free. Car doesnt pull to either side.

The rear sway bushings were still soft rubber, were not dry and cracking. The noise sounds most similar to the noise my 2010 jcw door made with the loose door brake bolt, but underneath the car and louder. But the car will only do it once or twice when it first starts moving, then never again until it's sat for a while.