nasty rattle

a loud

central, and

have ideas

Info from the garage section at

A1: The noise could be as simple as small rocks trapped in the heat shields around the exhaust system. Put the car securely on ramps or jack stands and inspect the shields. Small rocks can be pried out of the shields. When done, crimp the shields to keep this from happening again. A mechanic should be able to do this in under 30 minutes and charge no more than about $45.

A2: The heat shield above the exhaust header (manifold) may have a crack in it. If the car is under warranty see your dealer for a replacement. If not under warranty either replace the shield with a new one or simply remove the shield. Removing the shield will result in increased under-hood temperatures, but should not affect performance.

A3: The heat shield around the exhaust pipe has a broken spot weld or has a crack. If the car is under warranty see your dealer for a replacement. If not under warranty you have several options: use a 2 7/8" hose clamp around the suspect section of heat shield, remove the pipe and have the shield rewelded to the pipe, or buy a new section of pipe.

Good luck and happy new year to you too!

Iva & Belle.) '90B Classic Red.) #3 winkin' Miata

In Iva's response, A3 (broken weld on downpipe heatshield) is the most common cause, and the hose clamp ploy is the most common solution.

However, in my case it was a bad catalytic converter, and replacement was the solution.

It sounds like the Heat shield.... I had the same problem, but got mine removed.. and now the rattling is gone :o) "Carmen" skrev i en meddelelse news: snipped-for-privacy@corp.supernews.com...

Mine was a bad catalytic converter. If you can, get under the car, WAY before it has warmed up, and hit the catalytic converter. If it rattles inside; you'll have to replace it.

Steve McMahon Green JRSC '00LS

Watch it, the cat is designed to get *extremely* hot quickly.

Leon

"McMahon" wrote

And I couldn't tell for sure if it was heat shields or the inside of the catalytic converter bouncing around until I took the cat off and shook it. From these replies, a disintegrating cat is not all that uncommon for 10+ year old Miatas.

Just got my Miata back from Brainstorm. My 'BSP M2 Intermediate exhaust' ($299.00 New - 06/11/01) had, basically, uh . . . Total Interior Failure (my words). It had been buzzin'/rattlin' loud, RIGHT at 3000rpm since 06/03. Went underneath and bent heat shields, re-routed sensor wires - tried everything. Finally, about 2-weeks-ago, it started rattling like there were rocks-in-my-hubcaps or something.

Took it into Brainstorm. They have/are moved(ing). But they got it fixed in one day (today) by taking it to their OLD muffler-shop, welding in a new Cat and resonator AND getting it back to me by 5:00pm. For $224.94 - but - there is NO warranty - At All. That's okay by me. I got 2½ years and/or

21K miles out of the last ones. But I'm posting this to let others know that if you increase the Miata's hp, by ANY means, you are going to have to increase maintenace on the 'stock bits'.

Steve McMahon Green JRSC '00LS