My wifes A6Q exhaust has started making an odd muffled clanking upon acceleration. Does not do this at idle only upon acceleration. Everything appears to be tight with the exhaust, it appears to be coming from inside cat. area. Car runs fine otherwise. When banging on the area with a rubber mallet I don't hear anything rattling inside. Am I looking at a new cat. ? It's the original exhaust at 138K.

Any thoughts/suggestions would be appreciated !

 

Check the rubber donuts- hangers - the exhaust might be loose and hitting the undercarrage someplace.

 

If those rubber haggers broke, the cheap after market ones may quickly break, since they may not be reinforced as are the OEM. What you hear may be the creaking at the bolted joint between the exhaust pipe and the catalytic converters.

 

I had checked everything on the exhaust and I all appeared to be nice and solid. An interesting thing happened though, I took the car to work the other day after we had rcvd. several inches of snow and the sound has disappeared....nice and quiet. For the time being, I'll chalk it up to an Audi quirk. Thanks for your response!

 

Look again -- The rubber donuts and holders are not that easy to see