TresX

I have this rattling/vibrating/humming coming from what I believe is the exhaust system. My idle is smooth as silk, but on occasions will experience a slight vibration that is exhaust related. I was thinking maybe it was the cat. Anyone with first hand experience with a bad cat, if you could just describe your experiences for me, I'd appreciate it....

E55AMG99

Mine sounded like gravel rattling around in the pipes. The sound changes with RPM. Not a buzz or vibration sound at all. That might be the exhaust heat shield. It made a buzzing sound at certain RPMs.

TresX

Thanks for that.....well, thats encouraging.....my condition goes away if I accelerate even slightly. Oh well, I guess it's stage 1 all over again. Any other suggestions/experiences?

djamer

i had the exact same problem. i bet it's the cat converter. I had mine replaced at 35K. if you car is under warranty, you'll be covered. If not, i feel for ya, it will cost you around 800.00.

sadly, it's a common problem in Clks.

jtbeche

Mine was like that. The shield on my cat rattled a little just as I started to accelerate slowly but as soon as I went past something like 5 mph or got the rpm's up a bit it went away. It was just annoying. My mechanic just welded it a little to hold it back in place and I haven't had a problem since.

digi

Yes, to replace cat is expensive. My CLK's cat is screwed and its not covered by warranty

clk22

Your car is covered under warranty for 70000 miles just for the catalytic convert considering i just had mine changed and wat a difference its so quiet and i can acutually hear my resonator delete now!

E55AMG99

Hong Kong warranty laws are most likely different.

King320

I have the same little rattle in my car, its kindof annoying and i havent found any way to really test it so that i can look at it and see what's going on. Anyone have a link to a place that sells hi-flow Cats? I hear they're cheaper than OEM.

LorinserCLK430

it can sound like "vroooom vrooom- gurgle gurgle" if that makes any sense....

f4iman78

Go to the dealer and have them check the vehicle. If I remember correctly for the US, the emissions warr is 8 years/80,000 miles. They are pretty expensive if out of warrenty

MB AMG

Funny, I had my cats replaced on my '98 E320 4-5 months ago. Dealer said it was covered under warranty even though the warranty has never been renewed. LOL, I wanted to ask questions but didn't, simply said "ok!" Around $1000 CND.