I have a 2013 LS 460L with what appears to be the same noise. I've hear descriptions of the noise I am referring to as being very similar to this. One person I know also indicated the sound I had sounded like a fan belt as someone else on this topic mentioned.
The dealer I use also reports this noise is normal but explains what the noise is from. The dealer claims it is a noise caused by Direct Fuel Injection. The other person on this topic called it I believe Indirect Fuel Injection. It was explained to me that Direct Fuel Injection on the newer cars these day is different from the fuel injection engines of older days. The older cars had fuel injected into the cylinder on the out stroke of the piston. In Direct Fuel Injection engines, the fuel injection occurs on the in stroke of the piston (when compressing the gas in the cylinder). It is this injection during the compression phase that causes this clicking/tapping sound. In my car, I seem to notice the clicking/tapping all the time when the car is at idle because there is less engine noise at the lower RPM but I believe though I do not actually hear the noise that it must always be present but not audible over the engine noise of higher RPM.
