rnelson

Please Help!

I have a 2001 E55 with 64,000 miles. Overall condition 9.5/10. Have been plagued with a knocking on the passenger front side. I'm going to put things in a number sequence to help diagnose the issue.

1. Replaced sway bar bushings and links in hopes to stop knock. Result: Knock still there.
2. Installed vogtland springs. Result: Car handles and looks better, Knock still there.
3. Took car to indy shop, there specialty is not Mercedes. To see if they could see if they could tell what bushing is causing the issue. Result: They could not tell or see any bushing that was obviously bad.
4. Performed my own inspection with crowbar. Result: yielded some movement in farthest front passenger side busing of Lower control arm.
5. Replaced driver and passenger side Lower control arms, and ball joints. Result: Knocking gone
6. 2 weeks later had alignment done at dealer. Result: Steering Wheel now straight!
7. 2 weeks after alignment, knock comes back! Only on passenger side.
8. Noticed play in passenger side wheel. Changed out hub bearings on both sides. Result: Knock still there
9. More investigation to determine if I messed something up during installation. Result: Did not specifically load down the Lower Control Arm on passenger side.
10. Decided to replace upper Control arm on passenger side. Result: Knock still there.
11. Purchased new passenger side Lower Control Arm and installed making sure to tighten while pressure applied using jack to put a load on the LCR to the point where the E55 was lifting off the jack stands. Result: Knock is gone!
12. Waited 3 weeks before getting alignment done. Result: Steering wheel straight again.
13. 4th week, Result: Knock is back, passenger side! WTF !!!!!!
14. Noticed drop links don't look so hot on drivers side. Changed both drop links on sway bar. Result: Knock still there.


Questions... Is it possible that the Meyle LCA are defective??? Why does the knock go away each time I install a new LCA and then come back? I'm 100% sure the second installation was done correctly. Why is drivers side okay? All bolts are tight!

rnelson

I just took the E55 to a local expert, Bud at MB Motors here in Phoenix. First time I have met him, he has received good props from online forums. Right off the bat he said he thinks it is the springs causing different geometries with the suspension that is causing the issue. We took a spin around the block. He was pretty confident in stating that he believes that the LCA is still good. He said he would be more that happy to dive into the issue if I put the old springs on and the knock is still there.

He said I should do two things.

1. Remove the shock and turn it upside down and push on it to see if there is a bad spot. He stated that he has seen shocks go bad when different springs are installed.

2. He said if there is no issue with the shock to then swap out the springs back to OEM.

If the knock is still there bring it to him and he will investigate.

What do you guys think about his analysis?

Overall, he seemed great. He is definitely a purist, but he seemed extremely knowledgeable and willing to to help. So, when I throw my hands up I will bring it to him.

Thanks,

Rodney

Tall Giraffe

I would look at shocks- its the only thing you did not replace...

If they are OEM then they may be too long for the Vogtlands as they lower up to 40mm. There is a shorter Bilstien shock that compliments the spring set better which are about an inch shorter.

Still, before you had the springs, it popped, so it may be a bad shock not because of the lowering. I have a leaky rear and when cold or after sitting overnight it gives me a pop when I reverse occaisionally.

BTW, I replaced my upper and lower control arms with bushings with Myle and have not had a problem and they are holding up nicely for me.

rnelson

Hi Tall Giraffe, how can I reference new springs, the shorter ones that you are talking about? Thanks, Rodney

Tall Giraffe

You may have meant the shocks.

Here is a thread from a member here who has changed his shocks from Koni to Bilstein Sports. He is also on Vogtland springs.

Recent Changes Thread

Keep in mind that the shorter shocks will lowers your car more. If you like the current height you may need to measure and incorporate spring pads to adjust your height to your tastes. DDB is running a 2 front 3 back spring pad I believe. Each Spring pad has a different amount of bumps on the spring pad to signify the number and different mm thickness.

illest

swap the shocks from side to side and see if the noise follows. Springs should not cause a knocking noise.

rnelson

Thanks I will definitely swap them out left and right front shocks, good idea, I should have thought of that!

PJmak

Are you using spring pads or are you metal on metal?

rnelson

PJMAK,

I'm using the stock spring pads. Are you thinking that maybe they are bad? Can they go bad?

Thanks,

Rodney

PJmak

Na dont think they'll go bad I just thought maybe they were left out.

rnelson

I swapped the shocks. And took it for a spin. And it is driving great again!

I turned them both upside down and pushed down on them, they both operated smoothly with no dead spots. So I swapped them.

Took the car over my favorite speed bumps and down some bumpy roads. No knocks from either side! If it was the shocks, wouldn't I get a knocking on the drivers side now?

Is it possible that just loosening up the entire suspension and bolting it back together is causing something to shift, then over time it is shifting back to cause a knock?

There is nothing next to change except for the spring pads????

My brain hurts?

PJmak

I dont understand the part in red. Why swap they if there is no dead spots?

I think we need a better explanation of this knocking noise or possibly a video.


I think users here will know because a lot of us here do our own work.

rnelson

Hi PJmak,

I swapped them because although I thought they felt fine and similar to one another, I was not 100% sure that the passenger one was okay? I figured if there is an issue with the shock it would cease to exist if I swapped them and it would move to the drivers side.

Well the noise stopped and there is no knock on the drivers side after the swap.

I would get a video with the sound but it is not making now. I am suspecting that it will come back, as I don't believe that I fixed anything.

As I stated I have changed everything except the spring pads and one other thing I just thought of... what about the tie rods? I did not change those?

Thanks for all of your help,

Rodney