With your car off. tilt your hood all the way up and stand on the radiator support. Jump up and down in time with the rebound of your suspension. If it's your sway bar bushings, they will make noise by doing this.

 

Ill try that. Pushing up and down makes no noise. Noise is there only when backing up with wheels turned going over bump, or when going straight and braking hard and then letting go.

Going over bumps makes no noise.

 

There is a condition where your sway bar bushings will shrink and slip in the mounts. You would notice that going over speed bumps though.

 

that’s the issue. Going over bumps straight everything is tight.
Only when turning or hard braking.

 

Ordered lower control arm from Mb.
let the part throwing jubilee begin. Maybe throw in a sway bar while at it? New muffler tips?

 

I had a squeak/creak that I could recreate just by a light bounce of that corner. I injected grease into the main lower ball joint with the weight off the suspension and when I put the car down the noise was gone. It's been gone since May 2022. Apparently these sealed ball joints dry out. The boot was in good shape.

 

Thanks for chiming in.

I can’t recreate it with bounce. Only time is when turning. Left and braking or braking hard going straight. Or just backing up with wheel turned going over bump.

 

I had a noise like that on my E55. It ended up being an upper control arm bushing. I think I was able to wiggle it with the weight off the car. I think I even made a video of it.....

 

thanknyou. I went to a mechanic who did exactly this.
sway bar bushings began to sing. Otherwise there was no way to find the noise.

ao returning the new control arm and getting away bar with links and all.

 

Back at it again.
New sway bar, new links. MB parts. Still light knock when hard breaking, on and off brakes.
also when slowly backing up with wheel tuned right over uneven surface.
This is on driver side.

Bearing? Knuckle? Sunroof? Muffler?

I’m starting to think I’ll have to just live with it. But it sucks. Feels like subframe bolts are loose.

 

Did anyone really check the subframe bolts and retorque them? in fact all the bolts? Also IIRC that the bolts have to be final torqued when the weight of the car is on the suspensions . Did they do this when the front lower control arms were replaced ?

Also have the rear lower control arms for the front suspension been replaced? Thought i saw that you ordered them and then returned them?

Also if the sway bar bushings are being replaced, these also may need torquing with the weight on the car.....and make sure they lube the bushing surface the bar rides in BEFORE they install them.... BTW this allows the bar to rotate with less friction (stiction) , allows the car to take a set in the corners and avoids that slightly unstable feeling as the bar moves then stick over and over. AND eliminates any noise from the bushings. As ex race car driver and mechanic, ALL my cars get this treatment. So do SCCA cars and teams

Another thought..... have the struts been replaced? Creaking and groaning can come from the spring perch, the strut upper mount ( esp when turning due to binding, worn rubber isolator , frozen rusty bearing etc ) and the flimsy rubber cover that prevent dirt getting to the shaft of the strut. Being as it is only one side and when the car goes back and thru the dip in the driveway that is where I would start.

Let us know if you get them to look into that....

 

Thank you.

i was thinking about subframe bolts too. The morons that did my engine mounts two years ago said that subframe has to come down a bit. Maybe they didn’t tighten well.

struts are 1 year old up front.
lower rear control arms look mint and where changed at MB in 2019.

All ball joints were checked with crow bar. Zero play.

Whats weird is going straight no matter how bad the road everything is fine. Only under lateral stress or braking load plus bumps do I get this faint clunk.

going back to the shop to check it all out next week.

 

yep subframe not put back exactly right. When they take it down a bit again have them use an inspection camera to look for frame rubbing or torn/worn rubber isolator bushings on the subframe. Sometimes it can shift during re-install not lining up properly and that can cause weird noises as it moves slightly under pressure as you describe backing out the driveway.

When they did the struts did they change the whole thing including the top mounts or just the strut itself...im betting they just swapped out the strut amd resused the rubber spring isolators and top mount,,,Be good to check......

FYI you can get an inspection camera with 10 ft long wand and hi res screen with recording ability for <$200. If you can fit into various spots you want to check, then you can drive and record to see if its moving. I would try looking at the strut upper mounts and the subframe in various places. i have one and use it for things like inspecting tight areas i cant see very well including stuff around the house an on my RV.

Let us know how you get one