May 31, 2009 09:39PM
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Registered: 15 years ago
Posts: 636 |
If your exhaust sounds like it has a golf ball rolling around inside of it, what does that mean?
When running it doesn't seem to pose a problem (I don't think), but I was changing the back breaks yesterday and bumps the exhaust, and I could swear it sounds like there is a golf ball rolling around inside. Ideas? Is it just fine? Will it explode? Does this prove the existence of aliens? |
May 31, 2009 10:35PM
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Admin
Registered: 15 years ago
Posts: 600 : Portland, OR |
could it be the catalytic converter? |
June 01, 2009 12:53AM
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Registered: 15 years ago
Posts: 636 |
Since I have neither a problem with, or money to burn on, a new exhaust system, I have yet to bother with understanding the system all that much.
That said, I believe the cat is upstream of muffler in a distinctly different and self contained unit, in about the middle of the car. The sound I describe is definitely coming from the center of the last large metal container near the rear end of the car, only a couple inches from the rear bumper. I believe this to be the muffler :-) Sorry I wasn't more descriptive in my original post. In my mind I made "exhaust system" synonymous with "muffler", when really there are (or can be) multiple pieces to such a system. I don't pretend to know how exactly a muffler does it's job, but I wouldn't have guessed that there were objects within that, even if they broke off, would be spherical in shape, enabling them to roll around. If someone actually put an object up my tale pipe I'm going to start carrying a large stick around with me... |
June 01, 2009 04:36PM
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Admin
Registered: 15 years ago
Posts: 600 : Portland, OR |
June 01, 2009 07:01PM
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Registered: 15 years ago
Posts: 636 |
That is actually the only way I do hear it. With the car running, I don't notice anything too unusual. If the exhaust sound has changed since I bought it, it has been gradual enough that I haven't noticed. As I hinted at, I initially noticed because I bumped the exhaust pipe when I was changing the back breaks. The muffler hangers are worn and loose, so it had enough swing that when bumped, it moved side-to-side allowing for "the golfball" to roll around. I then grabbed the tail pipe and rattled it around and could hear something rolling around inside. If I hadn't bumped it, I never would have thought to inspect the muffler. I don't suppose it's hurting anything... I'd just like to know if A: It's a sign that my muffler is shot, and I should start budgeting, or B: There is no way it should make that sound, someone has stuck something up my tail pipe, and I should be concerned that it could cause a blockage and bring about damage. But I guess at this point the two of us are just shooting the breeze Anyone on these forums know anything about mufflers? Don't make me go find a river forum and ask them :tongue: |
June 01, 2009 07:08PM
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Registered: 15 years ago
Posts: 1,869 : Amagansett, New York |
June 01, 2009 07:18PM
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Registered: 15 years ago
Posts: 1,538 |
June 02, 2009 12:12AM
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Admin
Registered: 15 years ago
Posts: 600 : Portland, OR |
June 02, 2009 08:21AM
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Registered: 15 years ago
Posts: 1,869 : Amagansett, New York |
June 02, 2009 08:43AM
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Registered: 15 years ago
Posts: 636 |
Quite honestly I have no clue what kind of miles are on the Exhaust system. When I bought the car 3 years ago, there wasn't any paperwork on it, though it apppeared it relatively solid shape. Now, on closer inspection I see some rust on the very bottom of the muffler, something I've never seen anywhere else on my car (and is an odd thing for the inland northwest). So I presume that the muffler at least is far from new. Are there any at home tests for a CAT & Muffler system? I've never come across anything I don't think, but then as noted, I've also never cared |
June 02, 2009 01:30PM
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Registered: 15 years ago
Posts: 797 : Ottawa |
Inside the catalytic converter, the exhaust stream flows through a ceramic honeycomb structure. If the catalytic converter gets hit by a rock or it simply dies of old age, it is possible to shatter that ceramic structure and have bits of it blow right out the tailpipe. Or worse, it can get turned sideways blocking the exhaust flow. Viewed end-on, you should be able to see right through the honeycomb. Otherwise the outer surface of the honeycomb is curved to fit the contours of the converter housing. If a piece of it is now in the bottom of your muffler, it is possible that it will rock back and forth sounding like a golf ball in your muffler. |
June 02, 2009 03:47PM
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Registered: 15 years ago
Posts: 1,869 : Amagansett, New York |
June 02, 2009 07:31PM
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Registered: 15 years ago
Posts: 202 : Knoxville, TN |
Looking at the pictures Ferd posted, and considering the symptoms posted under the "swine flu" thread, makes me think the whole swine flu episode was due to the stuff that's in the muffler now working it's way down the pipe. It looks like it might be a good time to start shopping for a new exhaust system.
Give the catalytic converter a couple of smacks (when it's cool). Do you hear anything rattling around in there? John |
June 02, 2009 11:26PM
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Admin
Registered: 15 years ago
Posts: 600 : Portland, OR |
good thinkin! |
June 04, 2009 01:26PM
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Registered: 15 years ago
Posts: 20 : San Marcos, TX |
If you don't have the money for a new cat, I have taken them and removed the remainder of the catalyst material. Then welded a new pipe in the middle to make a "test pipe." Keep in mind this is not legal and probably will not pass smog inspection but it can save some money for a short time. The pipe in the middle prevents odd back pressures from the air flowing into different sized chambers. Also don't buy a cat from the muffler shop you can get one a high flow cat at auto parts store much cheaper and have it installed at the muffler shop usually for less then their cat or especially a BMW one.
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June 04, 2009 03:08PM
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Registered: 15 years ago
Posts: 1,869 : Amagansett, New York |
Well, that used to be more true, these days a new front section isn't that much, last one I bought from BAV was 300 or so. You start welding all those pipes together and you'll wind up spending just as much, unless you hack in a new converter into the old down pipe. That doesn't make much sense either. |
June 04, 2009 06:25PM
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Admin
Registered: 15 years ago
Posts: 600 : Portland, OR |
jus to help with price comparisons, i just had a headers-back exhaust built for my car with a new cat and muffler (2.5in tubing) for $700 total. the cat and muffler were magnaflow, and i think they were about $200 each. |
June 04, 2009 07:12PM
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Registered: 15 years ago
Posts: 1,538 |
June 05, 2009 10:05AM
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Registered: 15 years ago
Posts: 20 : San Marcos, TX |
jus to help with price comparisons, i just had a headers-back exhaust built for my car with a new cat and muffler (2.5in tubing) for $700 total. the cat and muffler were magnaflow, and i think they were about $200 each.[/quote] When they built your system did they crush bend the tubing or use mandrel bends? I was just on partstrain.com they usually have good prices and I can get a bolt up cat for $300 or one that needs to welded in for $67 for a magnaflow. |
June 05, 2009 10:33PM
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Admin
Registered: 15 years ago
Posts: 600 : Portland, OR |
mandrel bends. it took them a whole day to build it. it sits as close to the bottom of the car as possible without touching anything. really nice work. |