03 MCS with magnaflow exhaust not put on by me but by the previous owner (and it was a shop that did it not him) but ever since i aquired the MCS when i first start it after a long period of inactivity (4 hours) or its cooler outside my exhaust or a heat plate rattles. its annoying as hell, i feel like some of those ricers riding around by where i live. anyhting i can do to fix it?

 

Pull it up on some ramps and crawl underneath (please set your parking brake!) and see if anything is loose or hitting. It'll help if you can determine if it's near the front or back of the car, too. Might just be a loose screw that needs tightening. Good luck!

 

thought about that but it only happens everyonce in awhile then goes away.

 

I would suggest going under it and re-checking the work....I installed mine and it fits perfect! It could somehow be sitting to one side near the back where the straight pipe meets the muffler pipe, because it's narrow there.... so just make sure it's centered. While you are under there recheck the header bolts and the exhaust bolts to make sure everything is tight so the clamps don't move (if the clamps are moving it could cause it to rattle).

-Cody

 

cool ill try this.

 

i cut my cooling plate to fit.

 

When it heats up, does the rattle go away?

 

i think so. because at one point i thought it might have been a heat plate but lately ive noticed it does it when the engine is hot but its just been started as in ive let it sit for 45 minutes and the engine is still warm but i guess everything else cooled.

 

I Had the same problem after installing my CBE. Then i removed the heat sheild at the rear of the car. that fixed the problem

 

Mine sort of ticks a bit when its cooling down. I think its just the metal expanding and contracting from the heat.

 

Older Magnaflow systems were notorious for resonator problems.
The internal structure would break loose and rattle like you are describing.

Magnaflow replaced mine for free, even though I was not the original purchaser.

This has been discussed on NAM in several threads and many members have had there resonators replaced by Magnaflow.

Bill

 

^ That's very true as well.... I just bought a used Magnaflow from here and the previous owner had the res replaced by Magnaflow before I bought it.

Good point...

-Cody

 

when i get it up on the ramps ill check on that part.

 

i think i might have found the problem. i crawled under my car and found a 'bolt' loose. *'bolt' because its skinnier on the end than at the base and has a washer on it. it held the heat plate for the resonator tight, but it wasnt doing a very good job seeing as how it almost fell out when i went to tighten it. i hope this fixes it otherwise i gotta figure something else out.

 

ok. so i was driving my mini around today and heard the exhaust rattle so i was like lets figure this out, listened for it with my head out the window. it sounds like its coming more from right underneath me than at the back or front and it does it mainly between 3000 and 4000 rpm. resonator gone bad?

 

I posted a previous thread on a similar "noise" coming from my '06 MC after installing a Magnaflow exhaust. In my case, it was the hanger rod nearest the resonator that was rubbing on the heat shield wall. If you moved the pipe a little left or right, the vibration would disappear, only to reappear once the exhaust had re-centered itself. The Magnaflow hanging rod at the resonator does not have those little plugs at the end to minimize the amount of movement in the hangers...not sure why, as they did put them on the back hanger nearest the silencer (?). My dealer stuck some kind of rubber plug on the hanger rod at the end that was touching, and for the most part the problem has gone away. Magnaflow, do your homework and build these things right!

 

They did do their homework, and I like the design with no nubs, because imo the nubs just make everything a huge PAIN to install and uninstall... mine doesn't move at all.

-Cody

 

Obviously, they DIDN'T do their homework, as there are at least two of us out here with exhaust vibration problems...If your pipe has no way to keep it from shifting left to right on the hangers, you too will eventually hear what we are talking about...or you will remain just plain lucky and it may never happen to yours. With the nubs, obviously it will never happen to anyone.
BMW didn't put those nubs on their stock exhaust to make it look good...they are FUNCTIONAL...