Hollow exhaust sound when shifting

[98civex]

My stock d16y8 exhaust has developed a rattle noise at idle and when taking off if car bucks a little the exhaust momentarly sounds hollow almost like a bad muffler.

The muffler had a small rust spot so I replaced it thinking the other noises would be eliminated as well but they're still there.

With the car on a lift the hollow noise can not be reproduced by banging around. Nothing looks like it's hitting anything else like a heat shield or anything, there's plenty of clearance under there.

I tried listening to the header heat shield for noise but couldn't hear anything by revving engine up, it's more prominent underneath driver's side.

Any ideas?

 

[HeX]

I cannot picture what you mean by a "hollow sounds" from your exhaust. So here are some suggestions.

- Have you removed the heat shield and visually inspected the manifold for cracks?
- Also check the heat shield as its made of multiple layers and over time can begin to separate.
- Inspect the bolts and hangers throughout the exhaust path. Perhaps something else is damaged.
- Try tapping the catalytic with a long stick or rod & listen for rattling, indicating it needs replacement. Another trick is to you a flat end broom stick and hold it to the catalytic while the car is on. If you place your ear to the other end & hear rattling then its damaged. If the catalytic is clogged up from loose internal pieces, that could cause a back up of flow and bog you down during acceleration.

 

[98civex]

I cannot picture what you mean by a "hollow sounds" from your exhaust. So here are some suggestions.

- Have you removed the heat shield and visually inspected the manifold for cracks?
- Also check the heat shield as its made of multiple layers and over time can begin to separate.
- Inspect the bolts and hangers throughout the exhaust path. Perhaps something else is damaged.
- Try tapping the catalytic with a long stick or rod & listen for rattling, indicating it needs replacement. Another trick is to you a flat end broom stick and hold it to the catalytic while the car is on. If you place your ear to the other end & hear rattling then its damaged. If the catalytic is clogged up from loose internal pieces, that could cause a back up of flow and bog you down during acceleration.

It sounds like a muffler with the insides damaged/missing, if that makes sense. Mixed with metal clunking. But I can't reproduce it by shaking the exhaust system by hand. It's only noticeable if the car bucks a little when taking off in 1st gear. The acceleration doesn't seem affected and there's no exhaust leak noise while driving.

Went by a muffler shop for a quick inspection and the guy told me I have the wrong rubber hanger for the midsection and it's causing slack making the piping move making noise?

Is that possible? I thought all rubber hangers were the same. He said I needed a slightly shorter diamond shaped one and the one there now is the oblong one used to hold up the muffler. The price difference of the two is $12 from autozone (one I need being the expensive of the two)

If I do infact have the wrong rubber hanger, why only now is it causing the noise? I've replaced the mid pipe almost 4 years ago now with no noise but recently

http://www.autozone.com/autozone/parts/Exhaust-System-Hanger/_/N-9l4wr

 

[xxBLOOD88SHOTxx]

So the guy is saying your exhaust is loose, you couldn't tell this when you were under it?

 

[98civex]

So the guy is saying your exhaust is loose, you couldn't tell this when you were under it?

I'm not sure how tight an exhaust is supposed to be honestly, I did notice it give a little when I'd push up on it but I just thought that was normal.

So the difference in those rubber hangers does matter?

 

[xxBLOOD88SHOTxx]

Well for one I do not understand what the dude meant by there is "slack" in the exhaust. How does a metal tube get slack in it? A rope gets slack in it, floss can have slack, a snake can have slack, but a solid piece of metal?


You need to take pics of your exhaust, this isn't getting solved any other way as none of us are there to hear this "noise" or inspect your car.

 

[98civex]

Well for one I do not understand what the dude meant by there is "slack" in the exhaust. How does a metal tube get slack in it? A rope gets slack in it, floss can have slack, a snake can have slack, but a solid piece of metal?

He was referring to the rubber bracket having slack which is causing the exhaust to move

 

[98civex]

Update

Brought it to a local muffler shop and they checked for the noise with the car running. They said it's the resonator in the mid section, internals are broken and making noise.

Is it safe to drive it like this or can what's broken potentially clog up the exhaust?

 

[xxBLOOD88SHOTxx]

That's a first, didn't know there was anything in those resonators that could break.

 

[civic21911]

Yea I have run into this before with my MagnaFlow. It almost sounds like there is a smaller diameter pipe inside that came loose and rattles around.

 

[xxBLOOD88SHOTxx]

sounds like cheap resonators