rattling exhaust resinator

about a week ago i suddenly started hearing a really annoying rattle coming from my exhaust at low rpm's.

 

when the car is idling and i rev it a little, as it passes through the 1000-1500 rpm range it sounds like i have a rod knocking or my car is a diesel, especially as the rpm's come down. i listened as well as i could and it seemed to be coming from around the resinator.

 

so yesterday, i finally got it up on a lift to check it out. sure enough it is the resinator, but not from the resinator hitting something or a rock stuck in a heat shield. the noise is coming from inside the resinator.

 

i guess the resinator doesn't like my new boost levels (peak @ 18.4) because it seems like something let go inside of it. or maybe i just got a bad one. anyways, it has to go, and hopefully that will happen today. i'm going to have a straight pipe welded in place of it, since i doubt subaru will warranty it because of the new hardware that is residing just upstream.

 

i'll let you guys know how it goes.

lemme guess.... catless up and new dp with no cat. (total of 1 cat instead of stock 3)

 

it's backfiring, mine does it too. Most people with catless up's get this too.

 

 

i bet you'll still get the noise with the straight pipe, just might move around

Backfiring and rattling sound a bit different in my mind. There's no way mattg would be getting rapid backfiring around 1000-1500rpm. The occasional pop, crackle, etc I can understand...

Possibly blew out some of the 3rd into the resonator?

i'm totally catless. and this noise isn't popping or backfiring, as i can hear that as well when i rev it up higher and let it rev down.

 

my buddy at the exhaust shop confirmed it. there is metal on metal vibration coming from inside the resinator, and the sound is embarrassingly loud at low RPM's.

 

res. comes out tomorrow, and a piece of sleeved stainless pipe is going in it's place. can't wait, the sound is driving me nuts.

I have a similar sound when i let of the gas at idle, and i have no cats and no resonator. It's the extra rich mixture causing slight backfiring.

Well go ahead and replace it. But when you still get the noise, don't say we didn't tell you.

Does it sound like this :

 

http://media.putfile.com/Exhaust5142

 

There's alot of echo as the car was in the garage at the time, but it's backfiring.

i gotta rattle and no resonator. hmm. but mine happens over pavement irregularities at low speeds, so...

What's that heavy, useless thing still doing in your exhaust Matt?

ewww i have this noise..i have stock exhaust..sounds somethink like the motor knocking....let me know what you do to fix this...i could have sworn the noise was coming from the engine bay.

Well go ahead and replace it. But when you still get the noise, don't say we didn't tell you.

well, go ahead and take me for an idiot. i'll post a sound clip to help you comprehend what the problem is. there is a metal on metal rattle coming from inside the resinator. this has been confirmed by a couple of subaru experts as well as the best custom exhaust shop that i know of. it's not exhaust popping or backfire.

What's that heavy, useless thing still doing in your exhaust Matt?

it's on the way out. losing weight and gaining some rumble, for teh win.

I had this similar rattle. It almost sounded like rod knock or the timing belt tensioner except it came from the back of the car. It turned out to be coming from the mufflers.

 

Subaru is aware of the issue. In the last Tech Tips newsletter, there was an article that said they examined an STi muffler and discovered that a baffle had broken loose.

 

Jim

that's the same problem i have, but it's a baffle in the resinator that has broken loose.

 

http://media.putfile.com/rattle55

Yep...something loose in the exhaust.

Mine does it really bad when you start the car sometimes...and WOT you get an exhaust smell in the car

Mine does this as well and im totally catless as well, BUT mine only does it when its cold, as it warms up it goes away. But DEF post some results on the exhaust note after you take out the resonator i want to do it as well, i just dont want it to be too loud.

that's the same problem i have, but it's a baffle in the resinator that has broken loose.

 

http://media.putfile.com/rattle55

 

so, does anyone still think that sound is exhaust backfiring or popping?

as long as your sound in the same as mine i say no way.

yea this is 100% for sure not backfiring

i just dropped her off for a resinator delete.

i just dropped her off for a resinator delete.

 

Good choice. If you can, inspect the resinator post-delete. Take pics for breakage evidence....

POST A SOUND CLIP!!!!!! cant wait to hear it! do you have to stock mufflers still?

 

best of luck

POST A SOUND CLIP!!!!!! cant wait to hear it! do you have to stock mufflers still?

 

best of luck

 

Post #8 has a soundclip of stock mufflers with the resonator removed. Catless UP & DP though.