So I recently had the entire exhaust system with oxygen sensors replaced in my 95 camaro convertible. I began to notice a rattling noise as if something is striking the undercarriage coming from the back of the car when hitting a bump at >40 mph. I thought perhaps the muffler was not secured but the mechanic could not find the reason telling me the exhaust system is as secure as can be?? I made sure the jack assembly and spare were tight and doesn't seem to be the shocks. This did not occur before I had the work done. Anyone with ideas as to what may be causing this?

 

i would say its the exhaust. i dont think the mechanic is lookin to hard.

 

Exhaust should move around some. They are suspended on rubber because the motor moves and if they were not suspend on rubber you would feel all the engine vibration. When we install an exhaust system you have to make adjustments by turning one pc inside the other. Then you tighten the clamp. It is very easy to install an exhaust and have a rattle when done if you rush. Rattles after installs is very common for mechanics that do not do exhausts all the time. I would be lying if I said I never had one come back with a rattle. But I never had one I could not fix the second time

Two ways to check where the noise is coming from grab the exhaust and move it in all directions you can. If it hit something it is not adjusted right. If you still cannot find it start looking for something shinny near the exhaust. Where every the rattle is coming from should show signs of rubbing. While you are under there bump the Cat with the side of your fist to see if it is coming apart inside.

 

Get under the back of the car and have a buddy simulate road bumps by bouncing up and down while being inside the back hatch area. Then look for the rattle.

 

As you guys had mentioned and as I suspected, it was an exhaust pipe that was making contact in the middle of the car namely the support brace just past the catalytic converter...of course I had to take it to a local muffler shop to correct such a simple matter....wish it was done right the first time.

 

I have also as well had some strange rattling noise coming from the back of my car when going over even the slightest bumb, im pretty clueless as to what it would be. Just today had new rotors and brake pads installed and this noise appeared after. Any help appreciated, already put $2,000 into repairs on this in the past month!
02 v6.

 

is it a rattle, chatter or clunk. could be the pads where installed without using brake grease, could be the car jack is not secure, could be exhuast is to close to something and is hitting,

 

Rattles can be a huge PITA even for a master tech. I have ridden in trunks and under hoods. I have stripped out seats and pannels then gone for rides with someone else driving. Those where newer car cars under warranty I can not image rattles get better with age.

After saying that, I tighten my spare tire once a year. I could make it so I do not need to do it every year but it is a good reminder that I need to check the air in my spare.

 

Ive noticed after today it almost sounds as if the rotors are loose, everything was properly greased.
Its about the same noise as shaking a pop tab in the can.

 

I had almost the exact same experience with mine. I had muffler work done by a less than reputable mechanic, more than likely rushed his way through it and gave me back a poor finished product. I took it to another shop and they had to weld a patch and a small stabilizer on it because it kept knocking on the cross joint. If it rattled any more or any louder I was going to go insane!