View Full Version : Problem with new exhaust

10-27-2003, 08:29 PM
I replaced my stock exhaust with 2 1/4 downtubes, magnaflow resonator with 3 inch outlet then split into 2 1/4 magnaflow stainless steel mufflers. My problem is whenever I get on the gas in first or second gear it makes a rapid clunking sound. It sounds like the whole exhaust pipe is vibrating and you can feel this vibration inside the car. Does anybody have any ideas what could be wrong with this exhaust setup or what else underneath there could be causing this sound? Thanks in advance.


1994 5 speed

10-27-2003, 08:36 PM
Have shop fix exhaust

10-27-2003, 08:36 PM
All of your rubber isolators are supporting the wieght of the exhaust. Some of them might appear so, but due to slight misalingments, your exhaust could be contacting the floor pan, a heat sheild or a suspension crossmember.

I'd look closely at the NVH bar a foot behind the transmission and under the driveshaft. It ties both floorpan tubs together.

10-27-2003, 09:53 PM
I had this problem too and turned out to be the cats were hitting the underside + the motor mounts were shot. Replaced motor mounts and no more noise. Make sure you have atleast 1" of clarance between the floor pan and cats & pipes.

10-28-2003, 12:25 PM
Ha! I DIDN'T have this problem UNTIL I replaced the motor mounts. The new exhaust and new cats were fit with the bad mounts, then when the mounts were fixed (lifting up the engine a little), the cats started knocking! Had to go back and re-adjust the cats mountings.


10-28-2003, 04:08 PM
I really appreciate these suggestion! I was planning on replacing the motor mounts this winter so hopefully in my case they are the problem. I already had an exhaust shop check it out and they just rewelded some joints and sent me on my way. I will check my clearances under there and hopefully be good to go. Thanks again guys!

10-28-2003, 09:30 PM
I think SCP has the correct hight engine mounts. Most of the aftermarket mounts are about 1/2 to 3/4" taller thus putting the cats closer to the floor pan. If you have the clearance dont worry about where you get them from. I got mine from MN12 performance.