Dave B

For the past 8 months I've had a exhaust rattle that has gotten progressively worse. The rattle/buzz only occurs from 2000-2500 rpms depending on gear and load. With the windows rolled up it's no big deal, but with the windows down and near a object, the noise is very embarassing. The noise comes straight out of the muffler. At first I thought it was a brick in the RT cat that had come loose. I swapped in the stock cat and the noise was slightly quieter, but was still there so I swapped the RT cat back in (strike one, not the cat). A few months ago I got a Stillen B-pipe to replace my Courtesy B-pipe. Maybe the Courtesy B-pipe resonator had rusted out and caused the rattle? Nope, the non-resonated Stillen B-pipe made the rattle louder (strike two). I moved my train of thought to the muffler. Maybe a baffle had become dislodged a bit and was resonating under certain rpms. I get hold of a nice 99 muffler and the rattle is still there (strike three). Since I've replaced or swapped out everything on my exhaust EXCEPT for the Y-pipe since the rattle, my thoughts are it's the Y-pipe flex section.

Last night I looked into exit pipe of the Y-pipe while shining a flashlight on the outside of the flex section to see if light came thru. I couldn't see light so I doubt it's leaking. I didn't think it was leaking either because the sound is a rattle, not a hiss or "tapping" like a leak causes. I think something in flex pipe housing has become loose and rattles at certain rpms. I couldn't see anything that looked loose. I squeezed the flex section and it felt a little soft and "crunchy". I guess I'll have to bite the bullet and possibly get a new y-pipe. My y-pipe is over 2.5 years old, seen 3 salty winters, and is one the orignal Stillen pipes with the equal length tubes. I might just get the Warpspeed non-mandrel Y-pipe. I've seen GuidoSST's non-mandrel Y-pipe and I have little doubt the non-mandrel flows just as well as the mandrel. Warpspeed uses a special bending process that doesn't seem to kink nor restrict the bends. It's very smooth. $200 is all I want to spend because I won't be keeping this car anymore than another 1 year.

What have I learned? The stock muffler isn't prone to rusting out like some other imports. The RT car is less restrictive simply because more noise was noted. Trouble shooting exhausts is a big pain in the aZZ.

Anyone had this problem before?


Dave

UMD_MaxSE

iTrader: (1)

what kind of y-pipe?

Sprint

iTrader: (10)

cat bracket?

96sleeper

iTrader: (4)

I also had the same problem and it turned out to be the heat shields rattling back around the b-pipe. Just a thought before you have to spend money.

Synki

That was the prob w/ mine and it gave me a rattle feeling under low acceleration. After i swapped it out w/ hollowed out cat, i have no noises nor vibrations.

Sprint

iTrader: (10)

I wonder who gave you that idea?

Synki

Thank you Do... Darren.

Sprint

iTrader: (10)

ToYLeT902

iTrader: (12)

Sprint

iTrader: (10)

ericdwong

Why not? And what are you going to replace it with?

Dave B

I'll check the cat bracket and heatshield towards the rear of the B-pipe. I don't have a heatshield above the cat so that's not a problem. By cat bracket, do you mean the hanger bracket that supports the rear of the Y-pipe where it connects to the cat? Was anyone's rattling caused by sound reverberations and not necessarily metal to metal contact?


Dave

Jeff92se

iTrader: (82)

Look for sooty spots along the flex section. If you see them, that means the flex is probably leaking. I would try to wrap the flex w/ some header wrap to see if it quiets it down