Need Help With Exhaust Rattle

[Motor City Mad Man]

I have had a loud rattle in my right side exhaust for awhile now. I finally took off the right hand side sill and discovered that the exhaust pipe is contacting the frame where it passes thru from the engine compartment. I have Hennessey headers and Borla exhaust. There is no support or converter vibration isolator at this area like the stock exhaust system has. I thought I remember reading a message awhile back about someone having a similar problem with Hennessey headers and an exhaust rattle. I thought they said something about putting a shim in the right hand motor mount. What can I do to fix this exhaust rattle? I imagine that grinding the frame down in this area where the exhaust pipe contacts it would not be a good idea as it would compromise the integrity of the frame. Would a shim under the right motor mount work? Could I stuff a piece of rubber or something between the frame and the exhaust pipe? Any thoughts would be much appreciated as the rattle makes it sound like my whole car is falling apart.

 

[JimDavis MT 97GTS 650R]

Sean,You answered your own question... PUT A SHIM IN THE RIGHT MOTOR MOUNT. Do NOT put a piece of rubber between the frame and the exhaust pipe or possible fire may result.

 

[ACR Joe]

I had the same problem after installing a complete Belanger header/exhaust system. I solved the problem but loosening the motor mounts (the bolts on the frame side, not the engine side) and rotating the engine in the bay a few degrees. After loosening the mount, simply jack one side of engine (on the block, not the pan) using a block of wood on a floor jack.

This method was recommended by Lou Belanger and it proved to be quite effective. Good luck!