kaizmauka

Just noticed this when I put the car into R and start backing up I hear this metallic buzz...could it be the brake pads or the transmission...or perhaps the resonator? My LS has an x-pipe with a magnaflow resonator and no mufflers. Took the car to a shop but they couldn't hear the sound...

Any ideas guys?

cheers

yoitskenn

iTrader: (4)

Can you only hear the noise when moving? Or the whole time in reverse, regardless of moving or not. Try parking it on a hill, put the car in neutral so the car rolls backward. Can you still hear the noise then. If you can hear the noise, I’d say it’s safe to cross out transmission on the “possibility list”

911LE

Usually a metallic buzzing sound is caused by a loose heat shield somewhere underneath the car. Our cars have quite a few heat shields.

05ls430518

iTrader: (1)

I was gonna say the same thing that's usually the culprit.

tallcaguy

Agree heat shield. Fortunately I doubt it's the transmission

05ls430518

iTrader: (1)

I was gonna say you would have to be doing neutral drops and rev matching with the tiptronic all the time to blow up a ls430 tranny.

markwhit

My rear heat shield over the rear muffler was lose making some noise. I got under the car and tightened all the bolts to the heat shields. I think they are all 10 mm bolts.

StanVanDam

My rear heat shield over the rear right muffler became loose after 15 Canadian winters, and the stud nearest the rear bumper snapped off as I was tightening the 10mm bolt. I got a tube of JB Weld High Temp putty and solidly affixed the heat shield to the body.

Some people on the RX forums removed this heat shield altogether, although I think it serves a purpose of quickly absorbing and quickly dissipating heat from the muffler, and I would rather not have that heat build up on the car body.

Another possible source of this noise is the clamps for the heat shields on the exhaust pipes in the center of the car. Just crawl underneath and remove these clamps and heatshields altogether - they will eventually cause your exhaust pipe to crack, resulting in P0420 or P0430 DTCs and requiring full replacement of the Y-pipe if caught too late (patchable if caught early, but since the heat shield covers the part that cracks, very unlikely you will catch it early).