I have a W220 with a funny front suspension noise, and don't know what to look at first. Any thoughts?

-Most noticeable at the first stop of the day. I back the car down the driveway in reverse (no noise), accelerate to the stop sign, and hit the brakes. When I hit the brakes, I hear a crack/clunk as something in the front suspension shifts. Based on physics, it sounds to me like something is settling overnight and moving into a new position when I hit the brakes.

-You don't hear it easily the second (or later) stop of the day. It's loudest during the first.

-When going over bumps, potholes, or anything else, nothing feels loose

-However, going slowly over a speed bump can reproduce the noise just fine.

So it seems to be something shifting at slow speeds that is either inaudible or not happening again at high speeds. It seems to take the first stop of the day or a large speed bump to make it happen, so it appears to be most common in a low speed + sharp angle type situation.

A couple of thoughts:
-I have no idea how to check motor mounts (are these fluid filled?) as they usually don't look collapsed on these cars. I have put 60,000 miles on the car and have not changed motor mounts. I will have to look at the service records, but I don't believe the previous owner did either. BUT how can this be motor mounts if the car is smooth as glass when driving on the highway, idling, etc.?

-Strut mounts maybe? Or an upper control arm?

-Both control arms are relatively new. The skinny aluminum one and the large black one (with integrated ball joint) were replaced about 1.5 years ago.

I plan to jack up the front left and see if I can shift the tire in any way. Then I'll put it up on jack stands (with the suspension hanging fully) and see if I can make anything move on the left side that doesn't on the right.

Any guesses? Any ideas on what I should test and how? (ie. take a light pry bar and try to move ball joints/control arms/motor mounts?)

Thanks!

 

More information/testing might be required, as in what happens if you reverse again and then start off forward and stop....does the noise return loud after?

 

When I put it in reverse and try it again, it doesn't happen anywhere near as loudly as the first time. So it's obviously something settling over night, because I can't recreate it a 2nd time until I park it overnight.

But something is definitely loose...

 

i have the same thing going on, i suspect blown bushings of the arms.. its usually during the beginning of the day

 

Both lower control arms are new (the units came with all new bushings and ball joints).

So I'm assuming you mean upper ones?

 

ahh yeah, i need to replace alot of stuff on my car, it has 105k

 

also too my mounts need to be done, i believe it could be the culprit of the problem.. do u notice car shaking at idle? they are fluid filled i think

 

I have the same problem since few months , I brought the Car 2 times to the Dealer , I paid 2 times $ 148 and still they did not find where the problem is. I replaced 9 Months ago the Shock Absorber , I replaced in both sides Sway Bar Links, I replaced 1 Month ago Struts in both sides ( original ones) , at the same day I replaced Left side Low Control Arm ( original one ) and still I hear that noise in my Left side. Do I have to change everything to the Left side of my Car ? Dealer told me that I have to replace Mount Engine in my Left side. I do not know where to look , because the Dealer really can not find it or they just playing so, to make money ?