Exhaust Rattle?

[stprorolla49]

I have a Magnaflow catback on my Bullitt and it seems that something rattles everytime I hit a bump, and it got worse when I lowered the car recently. The same thing happened to my buddies GT vert when he lowered his, which also has a Magnaflow catback. I am wondering if anyone else has had this issue before. Is the tailpipe contacting the frame rail or the rear axle? It's not the tips being loose because that happened on my buddies car and when we fixed that, it was still making the sound. It's hard to diagnose unless the car is driving, so I'm just wondering if anyone else has had this problem.

 

[Barnaby]

Put it on jack stands and have a buddy wiggle the tailpipe while you're under there and see where it's hitting.

 

[Winters98GT]

they usually make contact under load on the passenger side above the axle. I agree with barnaby, get the car up and you can see where it is hitting.

 

[stprorolla49]

Yea, it's such a pain in the ass, I'm not really sure what to do if that is the problem. I absolutely can't stand the noise, the car just sounds broken. If this is indeed the case, should I dent the tailpipe in so it clears? Or put some rubber snubbers on where it contacts?

 

[twogts4us]

Mine doesn't rattle, but gives a solid 'tink' when hitting a bump too fast/too deep/too hard. It sounds like the axle lifting up and hitting the pipe, but that's expected, especially with a lowered car.
If your issue is more of a rattle, jack it and shake it as mentioned in the above posts.

 

[stprorolla49]

Yea I guess it sounds more like a tink sound but louder. Its really annoying. Maybe when it stops raining ill get under the car and check it out.

 

[nyuk98gt]

stprorolla49:

The exhaust has a lot of adjustment options. You can lengthen or shorten the gaps at the axle by loosening the tailpipe-to-muffler joint(s). You can rotate the tailpipes (axially [clockwise/counterclockwise] as you look down the pipe. There is not much clearance between the pipe and the corner of the gas tank. Check the U-bolts because they could be contacting the body or the driveshaft. You can rotate the threaded ends away from the point of contact.

As the others have said, put the rear up on a ramp so the suspension is loaded and get under the car and use the heel of your palm to whack the system so you can locate the contact point. It is a pain but it will be worth it.

Last thing, check the covers on your cats. If a weld has broken then the cover will rattle at certain RPM and that will drive you nuts.

HTH,

Chris

 

[stprorolla49]

UPDATE: Got under the car today and found out the stupid mounts on the Magnaflow tips were rattling like a mofo. The rod that runs along the top of the tip to allow for adjustability of the depth the tips sit in was tapping the top of the tip upon every bump in the road. I got some thick rubber gas line tubing I had in my toolbox and cut a little piece for each side. I slid the rubber onto the rod and it fit very snugly. No more tailpipe rattle.

I also noticed the tailpipe might occasionally tap the swaybay on large bumps so I took a piece of larger diameter tubing about 3 inches long, slit it longways and clamped it onto the swaybar right below the tailpipe. I took the car for a ride and took a few good bumps and there are no rattles anymore.