Rattling muffler...

[Peer]

Whenever I start the engine cold, my muffler rattles. I wonder if this is a common problem, and if so, is there an easy fix? And yes, after a few seconds, it goes away, hence, it's no a big deal -- but sometimes it's kind of embarrassing to start it up (cold) when people are around.

-- peer

[986Jim]

Something is loose around the muffler that is causing the rattle, as soon as a little heat hits it and the metal expands the rattle goes away. What you wanna do is get under the car when it's totally cold and start banging the muffler and pipes with a rubber mallet to see where the noise is coming from. Dont use a regular hammer cause it will make more noise than the rattle and you wont find it. The rubber will keep it quiet. Banging the tip probablly would be best just lightly enough to make the rattle happen. The start feeling around to see what is loose causing it..

It could be inside the muffler and not be a whole lot you can do about it. You can try banging the muffler in the spot that is ratteling it may stop it if you put a small dent in the metal, but could make it worse as well. If it's a clamp that holds the mid pipe (cat pipe) into the muffler then you can tighten it up and problem will be solved. Chances are it's not inside the muffler but something else that is doing it. There are only a few baffles inside there and it's welded pretty well so that things like that dont happen...

[Stefan]

It is almost certainly a heat shield, not the muffler itself. It is a very common problem. The bolts that hold the heat shield in place rust out causing the rattle. It is pretty easy to fix too.