HELP! Loud noise coming from the muffler!!

[classicauto]

Hello everyone!

I need your expertise. I have a 1995 Infiniti J30t and, for a couple of months now, it has been making a loud noise that seems to be coming from underneath the car and more from the muffler. It makes the noise sometimes when I brake, sometimes at high speeds and sometimes in the morning when it's cold. It never makes the noise just idling still. I got under the car and shook the muffler a little and after that it does not make the noise for a short while. There is a lot of residue in the muffler that I thought may cause the noise. Regardless, it seems that I will need a new exhaust system. Can anyone help me about the cause of the noise or locating a good exhaust system. I check with the dealer and just for the muffler alone it would cost me $700. Please advise.

[felixxilef]

How many miles on the car? Does it make the noise when you rev up the engine while it's in Park (not moving)? What happens at high speed if you put it in neutral ? I really have no idea, just some thoughts on how to narrow it down.

[InfinityLife]

I had the same problem and noticed that the protective shield plate was coming off the exhaust system. Finally, the bottom part fell off, however, the shield plate is seamed on the side edges -- leaving the top part of the shield above the exhause system almost impossible to remove. This loose portion of the top shield plate has caused quite a bit of rattling, particlarly at startup. This may be part of the problem. Unless you do a lot of off roading with your J30, this shield can be safely removed.