E55 AMG w211 front end clunk suspension over bumps with *video*
 

Hey everyone, I was wondering if you could help me identify my front end clunking problem. My car makes a lot of noises going over bumps in the road. It sounds like a bad shock absorber sound. I kind of rattles over bumps. I have already replaced numerous items including ball joints, front lower control arm, sway bar end links in the recent past. I have attached a movie to help you understand what I am talking about. I have had it inspected and all the bolts are tight and there is not much play in the suspension except there is some play in the part of the sway bar end link that attaches to the lower control arm (not sure if this is normal). Appreciate any advice. I am considering buying new air springs in the front from Arnott to help solve this problem.


Thanks everyone and I appreciate any and all advice you can give.


Ian

Wonder if it could be the motor mounts? Looks like it's moving around when you rock the car around.

Hi, that's a good idea. I did replace the motor mounts about 30-40k miles ago but that is certainly possible. I could try that test where you put it in drive and press the brake and gas and see if motor climbs out of engine bay. I'll update soon on results.

Ian

Take off wheel and go over bolts one by one... if it sounds like it is in the upper shock tower area it is probably the back two control arm bolts that need to be tightened

Report back when you have made sure everything is snugged up top to bottom.

That is not going to be a motor mount bc the motor is stationary at that point.

I am going to assume it is isolated to one side as that's where you are pushing down.

I did read one case where a new Arnott shock caused a similar issue but without more info its hard to tell

Start with tightening bolts

I had a knock in my suspension when I went over speed bumps. About a week after noticing it I got hit in the left front by a truck. The shop said they found a bent shock and replaced it, I haven't heard the knock sense. That was at about 112k miles

engine mounts checked video
 

Hey, just to follow-up on engine mounts suggestions. I have posted a video of me checking the engine mounts and they seem to be fine. I did put the car in drive while pressing the break will checking for engine movement and it appears normal to me but let me know what you think.


I will check the bolts on everything in the front left of car where the noise is more pronounced and report back. I did go through it with a mechanic while I was present and checked all the bolts already but I can do it again just to be certain.


I also heard of an Arnott having a similar clunking issue in the past which makes sense to me because I believe Arnott rebuilds used air springs so it could be that they didn't rebuild a section one of the components. I've noticed that most posts for malfunctioning air springs tend to be focused on loosing pressure but not actual noises.


Thanks again guys, keep the suggestions coming

pictures of suspension
 

Hey, I just wanted to post some pictures of the suspension components in case that helps. Also my car has 141K miles on it and is a 2005 model. Thanks!


I checked all the bolts and they seem tight. I wasn't able to check the upper control arm bolts behind the air spring unit because there was no room.

Its gotta be in the shock or the upper control arm back two bolts then :-/ hate to be the bearer of bad news. Prolly a good time to just Spend the $250 on some new Lemforder upper control arms while you are at it

my $0.02

what are the torque spec for those rear bolts on the upper control arms?

Thanks for the replies. I already ordered a air spring for the left front and will replace the old one as it's likely on its way out anyways given my high miles. It does seems to bounce around more than expected when you push down and let go of the fender. While I am there it will be a perfect time to check those upper control arm bolts and bushings to make sure they are tight. Thanks for all the input. Feel free to keep the suggestions coming.

*Tie rods inner/outer
*Torque strut arm ball joint

Are my guesses from what I've seen. That's not a strut noise IMO but could be.

1) disconnect tie rods from wheel carriers
2) repeat test
3) it noise still there reconnect tie rods and disconnect torque strut arm
4) repeat test
5) if noise still there disconnect away bar links (maybe not for the novice as they can be a bear to get back on)
6) repeat test

You really only have a couple wear points on the 211 that cause clunking like that. Ball joint, tie rods. Could be the strut but the amount of force you're using to get that noise makes me doubt it. I will bank on tie rods...I had arnots when I bought my car and they would clunk bad but I've never hear it outside the car only inside.

I worked on Mb for 10 years. This is how I would approach it. I quit a few months ago, never been happier :D

Hey! Thanks for the good advice. I will definitely try that diagnostic protocol in a day or two when I get back to town. I have replaced the outer tie rods already so it could be the inners that are bad. The car also make a clunk some times when turning the steering wheel. Hopefully that will help identify the problem.

Ian

I think mine does the same thing when I turn left into my street and go over the tiny bumps... keep us updated please

Ball Joints. These cars have a lot of them up front but look specifically at the one pressed into the spindle. I hate to dismiss everyone else's suggestions but until you've actually had the issue and solved it by doing the work yourself, stop guessing. Jack the car up and push/pull on the wheel. There should be NO movement or sound. If there is, there's your problem.

Thanks again for all the input and suggestions, it's very much appreciated. Just to clarify I have done all the work myself and as stated earlier I have already replaced all ball joints, outer tie rods, the strut control arm (front lower control arm) and the sway bar end links. I have not yet replaced the inner tie rod, lower rear control arm (the one the air spring and sway bar attach to). I am going to try and get that test performed with removing the tie rods and the end links etc and see if removing them fixed the sounds. I will start working on it today and tomorrow and will post update. Thanks again and keep suggestions flowing.

Ian

Jeez louise papa cheese you do all that yourself??? From jackstands????

update with photos
 

Hey guys, I may have found the problem but not sure. I noticed the bushing for the lower control arm (the one that the sway bar and air strut attach to) has some cracks in it and may be the culprit or possibly just an incidental finding. Either way it looks like it needs to be replaced. I have attached some photos. Let me know what you think.


Ian

Are you sure its not the sway bar itself? I know that is a common cause of clunking on these cars. Easy enough to test. Disconnect the sway bar ends and see if it still does it. I need to do this on mine but have not yet.

Honestly, that's almost definitely not it.

I'm siding with the folks who have already mentioned stay bars and strut (err, shock?) mounting points.

*Update, problem mostly now fixed, videos/pictures included
 

Hey guys,


Just wanted to provide an update. So while disassembling the left front of the car suspension I noticed that the upper ball joint was somewhat bad (see video of noise it makes when taken off car and compare to new part). After fixing just this item I put everything back together and went for a test drive and basically it didn't fix anything. So then I decided to replace my air spring/air strut with a gently used item I purchased on ebay and it basically fixes the problem. Now you can notice that the right side makes more noise. And since people with rebuilt units from Arnott are complaining of similar noises I wonder if sometimes Arnott doesn't rebuilt a certain component? Anyhow I still need to replace that bushing on the lower control arm but that part wont be available for a day or two. What do you guys think? I haven't yet checked the inner tie rods and will look into that soon.


Ian

I forgot to mention that I did try disconnecting the sway bar end links and it didn't seem to help with the noise but maybe I will try it again since the main loud noise is now gown and I am starting to notice other more subtle noises and it does seem like the sway bar may on its way out now that you mention it. I still get a popping sound when turning the steering wheel.

Sounds like you have a hog in there....oink oink😂🐷🐷

picture of sway bar bushings
 

Hey guys, not sure what good versus bad sway bar bushing look like but I have posted a picture of mine. Let me know what you think. I have tried spraying them with that lubricant mentioned in other articles but didn't help much.


Ian

checking bolts to be "seeming" tight is not good enough".. everything has a torque spec... to loose and you get clunk.. to tight and you get rapid wear. for instance.. the thrust arm frame nut is 85NM and the ball joint on the end is 90 NM... you have to remove the front under valance and front pan to get to the frame bolt... your rear control arm bushings a clearly toast....when i had my clunk i had the exact same look .. i decided to buy everything so i replaced upper balls, lower control arms and the primary lower balls, thrust arms(which include another ball) abd sway links i did it in stages but the clunk went away when i replaced the lower control arm.... as a side point.. i highly, highly recommend that you invest in the wurth HHS k lubricant and heavily spray your motor mounts...
.. I had super squeaky/noisy mounts and based on this forum i bought that product and it basically revives the mounts... i then sprayed everything with it.. its an unbelievable product..but expensive.. but then so are our cars !