2001 S430 Mystery Noise
Thread Starter
Newbie
Joined: Sep 2021
Posts: 3
Likes: 5
From: Federal Way Washington
2013 S550 4Matic
2001 S430 Mystery Noise
My 2001 S430 is making an odd metallic rattling/buzzing noise only under acceleration. Almost reminds me of a rattling lifter, or even a slightly cracked exhaust manifold. But the engine doesn't make the noise until I am in drive and accelerating. I can rev it in park--no noise. No vibration, no shuddering--just that odd rattle coming from the driver's side and to my ear closer to the firewall. Once underway the noise is not loud enough to rise above normal road noise, but it goes away completely if I let off the accelerator. The car only has 60k miles on it, and has been well cared for by it's previous owners who had it regularly serviced at the dealer. I just had my euro specialist mechanic replace the accessory drive belt, tensioners and pulleys which were past due for a change out, and they also tightened up a splash guard that they thought was causing some of this noise. Now the whole thing is quieter--but the rattle noise hasn't really changed. The mechanic seems to think engine mounts are the culprit. But everything I've read so far points to vibration issues with worn mounts--the car is silky smooth at idle and underway. Anyone experience this issue with their W220's? Ideas before I invest in engine mounts?
Thanks in advance!
Thanks in advance!
Thread Starter
Newbie
Joined: Sep 2021
Posts: 3
Likes: 5
From: Federal Way Washington
2013 S550 4Matic
Thanks Wally really appreciate the quick reply. Your suggestion seems like a logical start and makes sense because of where I am hearing the noise and the type of noise. I just couldn't get my head around how a weak motor mount could make the noises I'm hearing. Will update as soon as I get this done. That noise is driving me nuts.
MBWorld Fanatic!
Joined: Dec 2012
Posts: 2,473
Likes: 439
From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
While you are under there:
- Check both rubber U-joints carefully for cracks or failures.
- Carefully examine every place where the exhaust is close to the chassis for any signs of touching.
- Carefully examine the entire exhaust system for any signs of leakage or cracks.
- Check the lower engine covers for missing fastener or breaks.
- Check both rubber U-joints carefully for cracks or failures.
- Carefully examine every place where the exhaust is close to the chassis for any signs of touching.
- Carefully examine the entire exhaust system for any signs of leakage or cracks.
- Check the lower engine covers for missing fastener or breaks.
