exhaust rattle
06-08-2009, 09:52 AM
#1
exhaust rattle hey everyone lately when ive been going after a stoplight i can here a pretty loud rattle under the car. Its seems to be getting worse. It doesnt happen all the time tho just when leaving a stop light. I just had new exhaust manifold gaskets put in but its still there. I heard it might be the catalytic converter because as its original on a 125k mile LT1 car. Let me know what you think. Thanks!
06-08-2009, 09:59 AM
#2
On The Tree
Join Date: Mar 2006
Location: Boardman, Ohio
Posts: 121
Likes: 0
Received 0 Likes
on
0 Posts
I have a rattle from my exhaust also but I think my y-pipe is hitting my frame somewhere. It started after I did my headers and cat delete. No matter how hard I try I cant get it to go away. Plus now with my solid motor mounts ...wow
06-08-2009, 10:03 AM
#3
Your brick in your cat has broken away from the cat. Basically its just rattling around in there and breaking up, the longer it goes the more breaks off, the moree it will rattle. Mine did it, so i cut the cat open cleaned all the ceramic out and welded it shut. The exhaust will sound a bit more aggressive too
.
I hope you have a 1993 car. 1994-1997 lt1's had two cats and you cant get to them as easy.
.I hope you have a 1993 car. 1994-1997 lt1's had two cats and you cant get to them as easy.
06-08-2009, 10:24 AM
#4
Yea most likely it is the cat(s) coming apart, but I would not recommend gutting them and leaving it that way. The cat(s) being gutted will actually screw witht the flow since the exhaust is now entering a hollow cavity and getting pushed back into the pipe. I have seen a few cases where this can cost you power over straight pipes being welded in, let alone the added exhaust drone you will get from the exhaust bouncing around in the cat(s).
06-08-2009, 10:39 AM
#5
That may be true for the dual cat lt1's, but I had to do it to mine, and noticed a huge power gain because of how much the cat was plugging the exhaust. I also had no exhaust drone and it gave it an awsome tone, im sure a straight pipe would have been ideal, but this was a whole lot easier and dident cost a penny. I have lt's and ory now too, so thats all gone.
. 
Trending Topics
06-08-2009, 01:00 PM
#10
TECH Regular
iTrader: (1)
Join Date: Feb 2009
Location: PSL, FL
Posts: 400
Likes: 0
Received 0 Likes
on
0 Posts
Agreed...it is probably the pipe hitting the brace under there. If you don't want to throw it out, you can try and space it off the body some. That is of course if it is in fact the brace hitting the pipe and not the cat coming apart. I would get under the car and look at how close the pipe is to everything all the way down line from the manifolds first before chopping up what could be a perfectly fine cat.
06-08-2009, 01:27 PM
#11
ya i have a feeling its my y pipe because when i back in my driveway next to the house it sounds like its coming from by the front wheels. Prolly something little but im going to have my exhaust guy look at it on the lft and see. thanks for the info everyone!
06-09-2009, 05:17 AM
#15
On The Tree
Join Date: Jan 2009
Location: Waco, Tx/ Houston, Tx
Posts: 199
Likes: 0
Received 0 Likes
on
0 Posts
Your brick in your cat has broken away from the cat. Basically its just rattling around in there and breaking up, the longer it goes the more breaks off, the moree it will rattle. Mine did it, so i cut the cat open cleaned all the ceramic out and welded it shut. The exhaust will sound a bit more aggressive too.
I hope you have a 1993 car. 1994-1997 lt1's had two cats and you cant get to them as easy.
.I hope you have a 1993 car. 1994-1997 lt1's had two cats and you cant get to them as easy.
Sounds AWESOME!!! lol
06-09-2009, 04:16 PM
#16
I used to have a bad rattle sound coming from my cat area at stop lights and stops. That is until I swapped my sagging motor mounts to new poly ones, then it went away. Your mounts could be sagging w/125k on them. Btw I thought I had a F'd-up cat, too.
