exhaust rattling..what could it be?

[C280 JR]

exhaust started making rattling noise, also i noticed 3 times it happened, i stepped on gas from start the car chocked and made a poping sound from below the car not the engine...

[manny]

Sounds like the " guts " inside the catalytic converter is broken, causing it to rattle & choking off the engine. ;)

[C280 JR]

u sure about this...how much does it usually cost to replace

Elvir

[SpEeDy230]

Like I posted on Bnzsport. My exhaust made a rattling noise then 2 days later my muffler fell off.

[Don C230]

Happened to me a few years ago. Rattle lasted about 4K miles, then the "check engine" light came on. Yep, it was the cat.

You might get by cheaper by having an independent shop check it first (before a dealer). They also stand a chance of getting a much lower cost (but compatible) cat.

Don '97 C230

[Pablo7]

once my exhaust started making a funny noice in the back when i accelerated all the way.
i had it checked, and they told me a bolt that keeps the 2 parts of the exhaust system together (more or less where the rear wheels are) was not tight enought.
cheap cheap cheap ......... and noise no longer appeared
:D

[Paul]

Originally posted by Pablo7
once my exhaust started making a funny noice in the back when i accelerated all the way.
i had it checked, and they told me a bolt that keeps the 2 parts of the exhaust system together (more or less where the rear wheels are) was not tight enought.
cheap cheap cheap ......... and noise no longer appeared
:D

I had the same happen to me i just tightend and it was all fixed.
could well be the cat though,check for loose nuts first...

[C280 JR]

thanks guyz

Elvir

[Don C230]

ELvir,

Funny thing happened right after my last post on this subject: mine started to rattle again (slightly different, but similar, sound). I thought it was the cat again, so I took it back to the guy who replaced it a few thousand miles ago.

Good news was that the heat shield was vibrating against the O2 sensor - the better news was that all that needed "doing" was to "reform" the heat shied a bit - the best news was that I didn't cost me a dime!

As always, check for the easiest and cheapest things first. You could be lucky if you check.

Don
97 C230

[C280 JR]

will do, thanks don

Elvir