Magnaflow cat-back cabin drone...

[KrautBurner]

get a better muffler

mine has no drone
I have the Magnaflow 14377 (4x9x14) (with stock piping)
http://www.magnaflow.com/02product/shopexd.asp?zone=main&id=8680

Inlet/Outlet Size: 2.5in./2.5in.
Body Shape: 4in.x9in. Oval
Core Size: 2.5in.
Body Length: 14in.

 

[bahollis]

Well, unfortunately I'm not looking to replace my system with any other brand... since I just bought it, and I'm not calling any one a liar, but all the posts I read about the 15666 system said it did not drone at all either. So, I guess I got a loud one.
I'll most likely just deal with it.

Thx everyone.

 

[LuSe4]

Maybe your exhaust is vibrating against something. I have the same exhaust on my 2005 tahoe (5.3 liter). I also was concerned about drone, but took the plunge when amazon had them on sale. Mine is virtually silent at 75 with the radio and ventilation off. The only time i hear it is during acceleration.

Check clearances around the exhaust. Good luck!

 

[bahollis]

Hey luse4, did you use a gasket when you bolted on the inlet pipe? Instructions said to replace the existing one, but mine dud not have one

Also, is yours welded?

 

[LuSe4]

There isn't a "gasket", I am not sure what it is called, but where it bolts together there is a rounded protrusion that comes off of the pipe that you bolt to and lines up with the magnaflow pipe. This is the "gasket". (hope that made sense.)

Mine is not welded, either. I bolted mine on in the driveway. I did take it for a test drive and notice it was contacting my trailer hitch on bumps. I had to adjust the pipes some to get the correct clearance.

 

[bahollis]

OK. I thought so. It just seemed weird that the inst. said to remove and keep the gasket for re-installation.

This may be a stupid question, but does most of the noise and vibration exit right at the tips? (like I said, it seems like a "duh" question, but I want to know if I need to check for vibration elsewhere) I know the exhaust does, but does the muffler actually produce any noise that could be loud enough to produce cabin drone?

I adjusted the outlet pipes last night. It was not hitting anywhere, but I did notice that the plastic wheel well in the rear was loose and vibrated when it came in contact with the upper shock bolt, so I fixed that too. I hope that after a few adjustments it will be better. There's no way to lower the whole thing any more without putting pressure on the bolt-on part of the inlet pipe. I don't want to break anything, so I'll keep tweaking it.

thanks.

BH

 

[LuSe4]

I didn't drive it today, so i will check when i get home.

Is there anyway you could have an exhaust leak somewhere? I would say that the majority of the sound comes from the tail pipe.

Try loosening everything and just make sure that all of the pipes are pushed in far enough. Also check that the first pipe (the pipe bolted to the stock exhaust pipe) is not leaking.

Not sure what else it could be besides defective muffler. Maybe call Magnaflow and see what they say.

Maybe post a video from inside while cruising with the windows up and under acceleration if possible.

 

[bahollis]

you know, after securing the two places in the rear quarter that seemed to vibrate, and adjusting the exhaust outlet pipe to be a little further away from that same rear quarter where it exits I think it's a bit quieter. That exhaust has quite a rumble to it, and I could see how under acceleration it might cause vibration in the parts around it.

Now it only sounds like one person humming, but they're all the way in the back!


BH

 

[bahollis]

Update- I took your advice LuSe4, and loosened the entire system, and reseated it all. I thought that when I installed the inlet pipe to the existing exhaust, I may have needed to alternate tightening the bolts a bit to get it to seat straight, so I did that. I completely removed the outlet pipe, and reseated it and repositioned it. I was able to get another 1/2" gap between the stainless tip and the bottom of my rear quarter panel. I drove it a short distance, and it seems to be a lot quieter. I think the system is fine, I just had to tweak it a bit to get it installed correctly.

Thanks again

BH

 

[DJK]

go to a meineke and have them weld in a resonator