Front Suspension Noise (VIDEO) - PeachParts Mercedes-Benz Forum

dwylie34 · #1 02-01-2013, 04:03 PM

Hi there

I get this croaking noise when going over any bump in the road while making a right hand turn. It also occurs at freeway speeds on smooth roads while turning right. I feel it near my foot in the car while driving. Here's the link to the video (kinda fun to watch the whole front suspension in action too!):

300D Front Suspension Noise - YouTube

I have replaced the following:

ball joint
tie rod
guide rod mount
repacked bearings
upper control arm
lower control arm bushing
shock
rotors
break pads

I am considering that it could be a steering issue...any thoughts? Also, I have thought about the idler arm and/or steering dampener, but I doubt they could produce the feeling at my left foot while driving. PLEASE HELP!

Zacharias · #2 02-01-2013, 04:20 PM

I'm sorry I have no answer but I have to congratulate you on the most impressive diagnostic video EVER.

I would like to know what you used for a camera setup, if you don't mind.

dwylie34 · #3 02-01-2013, 04:23 PM

Thanks! It's a just a little Sony point and shoot in video mode that I used Gorilla Grip tape on to adhere to the inside of the bumper - a Joby would work best though. It was kinda fun to make, would be even more fun to figure out the stupid noise!

dwylie34 · #4 02-01-2013, 09:07 PM

Anyone?!?!?!?

Phillytwotank · #5 02-01-2013, 09:35 PM

are you suffering from Benz Hypersensitivity?

whunter · #6 02-01-2013, 10:16 PM

Quote:

Originally Posted by dwylie34

Hi there

I get this croaking noise when going over any bump in the road while making a right hand turn. It also occurs at freeway speeds on smooth roads while turning right. I feel it near my foot in the car while driving. Here's the link to the video (kinda fun to watch the whole front suspension in action too!):

300D Front Suspension Noise - YouTube

I have replaced the following:

ball joint
tie rod
guide rod mount
repacked bearings
upper control arm
lower control arm bushing
shock
rotors
break pads

I am considering that it could be a steering issue...any thoughts? Also, I have thought about the idler arm and/or steering dampener, but I doubt they could produce the feeling at my left foot while driving. PLEASE HELP!

My best guess from the good video

It looks and sounds like chatter contact between the brake caliper and wheel rim, and/or rotor.
If the wheel bearing adjustment is loose, this is possible.
If the caliper mount bolts are loose, this is possible.

Doubtful, but possible:
I assume you have inspected the inner plastic fender liner for witness marks of tire contact.

.

dwylie34 · #7 02-02-2013, 04:58 PM

whunter

I spent all afternoon yesterday looking at/prying on the suspension and nothing seemed suspect to me, quite tight. So I think you bring up a good point with the rotor/caliper contact points and/or wheel bearings - poking around there today. And yes, I have checked for wear around the wheel well - I initially was convinced that was what was happening, but it definitely is not.

dwylie34 · #8 02-04-2013, 08:37 PM

Just got done working on it and I found out the following:

It is NOT the wheel bearings or hub, I switched the hub, rotor, and wheel bearings from one side of the vehicle to the other and still the driver's side made the noise.

It is NOT the brake caliper, I actually removed the caliper from the knuckle assembly so it would not clamp on the rotor, and the driver's side still made noise.

It is NOT contact between the wheel well and tire, I wiped bearing grease on the every single spot where their could potentially be contact assuming it would wipe off or show some evidence of contact, all to no avail. And the driver's side still made noise.

I checked and re-checked every nut and bolt for tightness and everything was fine. And the driver's side still made noise...

dwylie34 · #9 02-16-2013, 10:19 PM

The other day after replacing the steering knuckle and sway bar bushings (driver's side was an adventure...) I took er for a spin around the block on the same route in the video. It still made the noise. However while reversing into my driveway with the wheels cranked, I was able to hear the noise for the first time without compression of the suspension. I had my wife sit in the car with it in reverse with her foot on the brakes while I popped the hood and looked around - and I finally found what it was. On the IP I saw that the pump itself was making contact with the steering box! When I leaned my weight against the block, contact ceased and the noise went away...it is the motor mounts and specifically the driver's side that had collapsed allowing the engine to sway enough the left on right hand turns and especially when coupled with any road bumps and therefore rub against the steering box. Such a relief to find it, and I now have the drivers motor mount replaced and will do the passengers in a few days.

SD Blue · #10 02-17-2013, 12:33 AM

Wow! If the motor mount is collapsed that badly, I would also check the oil cooler line nearest the power steering pulley. My motor mounts weren't near that bad and I can see where the pulley has rubbed the oil cooler line a few times.

Stretch · #11 02-17-2013, 03:03 AM

That is the best video ever! I wish I'd seen this thread sooner - though I must admit I probably wouldn't have said engine mounts. I'd have probably said something about slip plates and bouncing the car up and down...

...you wouldn't have reproduced the sound - it would have been frustrating...

gatorblue92 · #12 02-17-2013, 07:35 AM

Wow very impressive video! I would have never guessed it was the motor mounts either.

Steve-H · #13 02-17-2013, 08:11 AM

+1 for an awesome video. I think I'll do the same (just for fun though !)

Glad you got it squared away. Motivates me to replace my mounts proactively.

dwylie34 · #14 02-17-2013, 04:15 PM

Thanks all, it is very satisfying to have a modest victory!

SD Blue - good thought on the oil cooler line too. your response prompted me to get up and check it out and all is well fortunately.

whunter · #15 02-18-2013, 12:52 AM

Quote:

Originally Posted by dwylie34

The other day after replacing the steering knuckle and sway bar bushings (driver's side was an adventure...) I took er for a spin around the block on the same route in the video. It still made the noise. However while reversing into my driveway with the wheels cranked, I was able to hear the noise for the first time without compression of the suspension. I had my wife sit in the car with it in reverse with her foot on the brakes while I popped the hood and looked around - and I finally found what it was. On the IP I saw that the pump itself was making contact with the steering box! When I leaned my weight against the block, contact ceased and the noise went away...it is the motor mounts and specifically the driver's side that had collapsed allowing the engine to sway enough the left on right hand turns and especially when coupled with any road bumps and therefore rub against the steering box. Such a relief to find it, and I now have the drivers motor mount replaced and will do the passengers in a few days.

Can you post comparison pictures of the engine mounts, new and old.
Please send me a copy of the large raw files.

.