I have this very irritating exhaust rattle that comes from my cat/downpipe area. At first I thought that it was my heat shield over my cat, but after banging on it with a mallet, I found out it was in front of the cat.

It only rattles at about 3k rpm and is pretty loud. Does anyone have any idea of what might be causing this rattle? Replies will be greatly appreciated

 

I had this nearly very same problem (my rattle came at about 2k rpm) but I finally found out what it was on Thursday. Unscrew your corner housings and look inside the bumper cover up near the actual bumper. There is a gap there where the bumper gusset sits. It's a plastic piece. Mine was rattling around in there, but only at certain rpm (frequency). I just wedged a couple of spacers in there and voila! No more sounding like a poorly running diesel upon start-up. Just an offering...

 

^^I appreciate the help man but this sounds very metallic, like a piece of metal is bouncing around.

Any other thoughts?

 

i had aftermarket 2 peice headers, and the rattle for me was comming from the nut and bolt holding together the header. 1 was lose, and would rattle like crazy!!!. even @ idle.

 

take it all apart.....

see what you find.

 

This is usually your A-pipe. That is the second piece attached to the header. It has an inner and outer tube. The inner tube starts to break up and rattles at certain rpms. The part alone is ~$500 from Acura which is crazy. Time to buy an aftermarket header 1 piece or two piece or buy a JDM 4-1 header that you can still put oem heatsheilds on for $400 - http://www.hmotorsonline.com/

 

thanks for all the help guys

 

i had this problem a while ago and i thought it was my cat. it turned out to just be a loose o2 sensor. maybe its that?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDMEK9R &raquo;</TD></TR><TR><TD CLASS="quote">i had this problem a while ago and i thought it was my cat. it turned out to just be a loose o2 sensor. maybe its that? </TD></TR></TABLE>

Naw i looked at them both and none are loose.

 

UPDATE!!!

I replaced the flange gaskets on the exhaust manifold today while i had it off the car. The old ones were pretty f'ed up so i thought it might fix the rattle.

Well, it still rattled so i started to look again in the cat/downpipe area where the noise appears to be coming from. I played around with the heatshields on the cat and it still rattles. Does anyone have ANY idea what this rattle could be? I might have to take it to a shop which i hate doing so replies will be appreciated

 

Do you have access to a weld gun? I had my mechanic weld through the A-Pipe in a bunch of different places after I read about someone else doing the same thing. It looked like it had warts but it stopped the rattle for about a month but the pipe was just worn out and started again. It drove me nuts. I bought a oem replica a-pipe from some online store for $125. I put it on myself but had an exhaust leak. $300 later I learned from the muffler shop that it had an uneven flange - Bastards at the online parts store told me to suck it.

Sorry to say the same thing again but I think that is it

Good luck with resolving it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tucker8235 &raquo;</TD></TR><TR><TD CLASS="quote">Do you have access to a weld gun? I had my mechanic weld through the A-Pipe in a bunch of different places after I read about someone else doing the same thing. It looked like it had warts but it stopped the rattle for about a month but the pipe was just worn out and started again. It drove me nuts. I bought a oem replica a-pipe from some online store for $125. I put it on myself but had an exhaust leak. $300 later I learned from the muffler shop that it had an uneven flange - Bastards at the online parts store told me to suck it.

Sorry to say the same thing again but I think that is it

Good luck with resolving it.</TD></TR></TABLE>

If that is the problem i might as well buy a new header.

 

I had a bad rattle and it started around 3k or so. Then it seemed to die down but i think it was because my intake noise covered it up. At first I thought it was a heat shield rattling so I didnt worry about it to much. it ended up getting louder and threw my car on a friends lift ended up the heat shield broke because my midpipe rusted through and was flexing. It was a really small crack so I just dealt with the heat shield until my exhaust came in. Well the heat shield fix made the exhaust vibrate more which basically ended up breaking my midpipe in two. I would check for an exhaust leak make sure it isnt your exhaust, but on the bright side I ended up ordering an Apexi WS2 from a vendor on here $419 shipped

 

dude i know this sounds whack n all...but maybe its just a loose tightening clamp that needs to be tightened...happend on my friends jeep, there was this rattling sound by his cat and we lifted it...found a loose tightening clamp...replaced it with a new one cuz it was all rusty n ****...and the noise wasn't there anymore...i'm just sayin maybe u kno?

 

naw its not the cat back portion of my exhaust because i have a greddy sp2 thats pretty much new.

 

UPDATE!!! I replaced my cat today thinking it would get rid of the rattle. However, it still does it and its more high pitched. This is so freakin frustrating!!!!

So far, ive replaced all the exhaust manifold gaskets, re-torqued everything, and put on a new cat. However, when I was tightening the spring bolts that connect the cat to the exhaust manifold, I noticed that the springs are very soft. Could this be the reason of the rattle? Have they gotten weaker over time? Replies will be appreciated

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by skynyrd006 &raquo;</TD></TR><TR><TD CLASS="quote">naw its not the cat back portion of my exhaust because i have a greddy sp2 thats pretty much new.</TD></TR></TABLE>

Even though you have a new catback system, it may still rub on a couple of the heat shields. My first greddy sp used to rub against my shifter....so I bent the hangers down. Now my apexi ws2 catback system rubbed along a heatshield by the "s" shaped pipe. I had to bend that heat shield back to make it clear.....what I did was put the car in neutral, hung my head underneath the car and rev your motor until you hear the rattle...then try to locate the area where the rattle/noise is coming from.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iH8RICERZ &raquo;</TD></TR><TR><TD CLASS="quote">Even though you have a new catback system, it may still rub on a couple of the heat shields. My first greddy sp used to rub against my shifter....so I bent the hangers down. Now my apexi ws2 catback system rubbed along a heatshield by the "s" shaped pipe. I had to bend that heat shield back to make it clear.....what I did was put the car in neutral, hung my head underneath the car and rev your motor until you hear the rattle...then try to locate the area where the rattle/noise is coming from.</TD></TR></TABLE>

It doesnt rub on any heatshields. But i never thought about it hitting the shifter. Appreciate the help man

 

have a friend revv the engine untill you can hear the rattle. have him hold the revvs so that the rattle continues. next, start from the header, and work your way down frome ther untill you find the exact spot the noise is coming from. place your hands at the spot the noise seems to be comming from, and see if you cant get the noise to quit.(be sure to wear some wleding gloves so you dont get burnt)

thats how I have found and fixed quite a few of my own exhaust rattles.

 

The rattle is most likely comming from the bottom half of your exhaust manifold, almost every OEM b18c manifold with 60,000 plus miles does it,a peice inside braks loose and rattles, mine did it too at about 3k rpm, the easiest fix is to put aftermarket header on.

 

It's the a-pipe. I had the same problem on my GSR when I first got it stock. After removing every heatshield from the exhaust manifold to the cat-back, I changed the manifold to a header(traded for one, didn't go out of my way trying to get one) and that fixed the problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PACT man &raquo;</TD></TR><TR><TD CLASS="quote">It's the a-pipe. I had the same problem on my GSR when I first got it stock. After removing every heatshield from the exhaust manifold to the cat-back, I changed the manifold to a header(traded for one, didn't go out of my way trying to get one) and that fixed the problem.</TD></TR></TABLE>

Its not the a-pipe because I had it off the car to check it out and its fine.

 

Did you just shake the a pipe or did you actually start up the car with it off and it still rattled? Because just shaking the a pipe off the car, I doubt it would do anything.

 

Damn, I have the same exact problem. =\ Mine is at 3.2k rpm and it's hella loud =[

 

theres a TSB published on this... its the downpipe. good reason to get a header.