I just recently purchased a low mileage Lexus Certified GS350. As I was driving it on the surface street, whenever I would drive on a "wavy" or "bumpy" road, I would a hear a tapping noise coming from the left side of the car. When I got back on smooth streets, the noise would stop. I have taken it back to the dealer, and I was told that the "tapping" is a normal sound for the GS350. The sound is just enough to bug me.
Do you fellow 4th generation GS owners hear the same tapping noise when driving on bumpy roads?

Your input would b greatly appreciated...

 

What's the mileage on her? Is the tapping sound kind of like a rattling sound?

 

It has 18500 miles... It sounds like a knocking or tapping noise on the chassis... The dealer technician says he heard a tapping noise, but its normal for a GS350... but this is my third GS and none of my other GS's made those kind of sounds.

 

mate, is it possible that you record the sound and post here?

 

I know I dont have a GS, but is it a metallic-like noise? if so, it's more than likely an E-brake cable. Next time when you park for a couple hours, engage the E-brake for that period and see if the noise goes away when you drive the car again.