LAWYER2

01 S430 101k miles

It was happening periodically, now it is more persistent. I know its hard to diagnose a noise on a web-forum, but most of us seem to have similar problems associated w/ w220's. I guess I would describe it more of a rattling, and its more distinguishable when in gear, but when I put it in park it's still there. If I had to describe it on another vehicle I would say it almost sounds like a heat shield rattling on a Catalayc converter.

newton22

Can you pinpoint where exactly the sound is coming from?

~CL500~

I had a similar sound on my 215. It would sound like metallic rattling, like a heat shield or loose exhaust bracket. More pronounced in gear than in park, just like yours. When your car is in gear and ready to drive, open the drivers door and confirm the sound you hear is from under the car. If so, my guess is one or both of your cats are bad. The ceramic material inside the cats can get brittle and deteroriate over time causing this type of noise. If you can get your car on ramps or jack stands, take a peek under the car to confirm the shields and brackets are good. Also, try tapping on the cats and if you hear a "beans in a can" sound, then your cats are probably shot. Good luck

LAWYER2

ok, I popped the hood this weekend, and it's definately NOT coming from the engine. I got on my hands an knees and listened from under the car, and that is definately where it's coming from.

How much should I expect to pay for a cat replacement for one or both?

ibeforreal

I believe the cats are warranteed by Mercedes for 80k miles or 8 years. I just had both mine replaced on a 2003 S500 with 55k miles and there was absolutely no cost to me from the dealer.

LAWYER2

I have 102k miles :=( should I still try at stealer or go to independant and prepare to spend some $$$ regardless

ibeforreal

I would certainly try the stealer first since I'm not certian that it is 80k miles. HE might just cut you a break. Can never hurt.

E43 S

http://www2.partstrain.com/store/?N=...ND(universal:1))

Make sure you know what side is going bad.
Driver and Passenger sides are different...and theres a price diff also.

http://www.1motormart.com/unified/?N...20Benz&md=S430
i have ordered them from here for my W210, everything fit great, 90$ change at any indi shop

E43 S

By the way...first check the dealer...they are 80k or 8 years guaranteed

LAWYER2

do they brands matter? $75-$450 is a quite a price difference

denemator

My 2004 S430 with 109k miles runs beautiful except during warm up, it has a slight knocking sound like preignition (pinging) it disappears after about a mile or so and then purrs like a content kitten. It does it under load, not at idle. The purge valve does make a ticking noise at start up during idle, but that also disappears after a little while. It does not use oil and the oil stays very clear, It is serviced with 5W30 Syn. is this common?

D