Exhaust buzzing sound

[Mrbowtie26]

Quick question. After I went with my current exhaust setup (tsp 2" primary LT headers, cat deletes and full 3" dual with x pipe through 2 flowmaster mufflers (quad tips) it sounds absolutely sick however at a certain rpm/load there is a horrible buzzing sound from the right rear of the car. I've triple checked the exhaust and nothing is close to rubbing and I can't duplicate it by banging underneath the car. Almost like a heat shield rattle from hell. Any ideas or anyone else ever get a similar sound from the right rear ?

[frankwjr]

Have somebody back there and rule out the muffler itself...hopefully not a internal weld prob...good luck...

[Mrbowtie26]

Originally Posted by frankwjr

Have somebody back there and rule out the muffler itself...hopefully not a internal weld prob...good luck...

Yes that would suck. Problem is it only does it while I'm driving under load. Maybe I could duplicate it while at a stop in gear but idk.

[christianchevell]

Sounds like your most likely lugging the engine in a zone we have as all cars have where theres more vibration down low and your hearing it shake.... I get mild buzz on a stock NPP exhaust if I am luggin it down low in a small window where crap is more likely to shake in the console also.... which does not help, but its very minor and only noted if dogging it around town prolonging my being a rolling turd coasting from light to light practically after getting up to warp in .0000000000002 seconds. So even with other mufflers yes you would be a more prone to vibration zone when luggin or in a certain rpm, but yours may have a weak baffle that's more prone to sing with that harmonic....

[Mrbowtie26]

Originally Posted by christianchevell

Sounds like your most likely lugging the engine in a zone we have as all cars have where theres more vibration down low and your hearing it shake.... I get mild buzz on a stock NPP exhaust if I am luggin it down low in a small window where crap is more likely to shake in the console also.... which does not help, but its very minor and only noted if dogging it around town prolonging my being a rolling turd coasting from light to light practically after getting up to warp in .0000000000002 seconds. So even with other mufflers yes you would be a more prone to vibration zone when luggin or in a certain rpm, but yours may have a weak baffle that's more prone to sing with that harmonic....

All I know is it is a very very loud buzzing

[RLHMARINES]

Originally Posted by Mrbowtie26

All I know is it is a very very loud buzzing

The sound that you're experiencing maybe drone and not a rattling or buzzing exhaust. A full 3" exhaust with LT headers, off-road pipes and free flow mufflers will drone in a certain rpm range.

[MrChrisLS3]

Originally Posted by RLHMARINES

The sound that you're experiencing maybe drone and not a rattling or buzzing exhaust. A full 3" exhaust with LT headers, off-road pipes and free flow mufflers will drone in a certain rpm range.

Or probably more accurately described as resonance. This is when the vibration from the exhaust in certain conditions causes other parts to vibrate and they are either rattling against each other or the vibration itself is causing the part to make noise. Kind of like how an acoustic guitar works.

It could very well be a heat shield, not rubbing against the exhaust itself, but vibrating against the tunnel wall. Something along those lines.

[ClawSS]

Maybe not your scenario at all, but "under load" could be what I had to consider with my 3" exhaust.

After headers and TSP off-road pipes were installed, I would get a rattle. Not a buzz per say, but marbles in a can. This would only happen under load and after warm.

I put the car on the rack and loosened the driver side motor mount as much as I could without removing the nut and then jacked up that mount stud thus rocking the engine to the right to simulate the torque.

I found that my pipe right at the bend headed to the x-pipe would hit the "frame" and contact the heatshield way before the cat-like off-road pipe would contact.

I loosened clamps...pushed, pulled, pryed, and prayed and got more clearance (maybe a 1/4" more than previously at rest).

No more buzzing/rattling. I may need some stiffer motor mounts.

[KYVOM1LE]

Would agree with MrChrisLS3...I have the stock NPP and noticed that resonance/metallic vibration sound at 1000 to 1200 rpms (under a load)...Right now do not want the dealer to mess around and try to find the solution....For now

[Mrbowtie26]

Originally Posted by RLHMARINES

The sound that you're experiencing maybe drone and not a rattling or buzzing exhaust. A full 3" exhaust with LT headers, off-road pipes and free flow mufflers will drone in a certain rpm range.

Not drone. I'm fully aware of and experienced drone before.