rattling sound on idle from undercarriage

[K_Po_Uno]

I'm getting a rattling sound on idle from my undercarriage. It cuts in and out, and it gets worse when the AC compressor cuts on, but is still present when it's off.

I suspect catalytic converter or muffler. Little help, please.

Thanks

[onewhippedpuppy]

Roll under there and start banging on stuff, you should find it quick enough. Check all your clamps, rubber hangers, and heat shields. If the cats sound like they're full of marbles when you hit them, they're probably shot.

[ILoveMPower]

Probably your heat shield, mine is torn up.

[pyro]

i vote exhaust shields

[genphreak]

i vote exhaust shields

If it is the floor pan shield, (in the tunnel between exhaust and drive shaft) the best solution is to pull the exhaust (undo 10mm nuts at manifold (replace with new ones as they are cheap using anti-seize compund) and release the centre rubber donut/hanger), undo the 10mm plastic fastners and then remove the heat shield. take it out, clean it on both sides and then bend it back just enough that it is a positive poressure fit on the undercariage of the car when bolted back up. If it shte heat shield around the cats then re-tack it ONLY where the original tack-welds were. Worked on mine which had both problems! Nick

[Jay 535i]

i vote exhaust shields

Second.

[Kobe Diesel]

if it's rotational, using a stethescope can help in localizing the noise

[K_Po_Uno]

woow, thanks fellas... I love this forum... next time I see ya, beers on me.