I have a 2005 TL 5AT non-Navi with about 1500 miles on it. At the 1000 mile mark, I have begun to try full throttle acceleration. I have noticed at higher rpms (5-6000) there is a high frequency sound from (I think) in front or inside the dash. It sort of sounds like a trickling sound. I first thought it was pinging. But I think it is also there if I just rev the engine - I don't think revving the engine without a load is a good idea so I have been reluctant.

Has anyone else had this problem/sound?

I have added octane boost to 91 fuel - no difference.

It is a bit of a let down because I dont remember this sound during my test drives. I just remember a fantastic high revving engine/exhaust.

 

I'm guessing by your description that the sound is a rattle coming from inside the dash or center channel. If I were you, I would have the service center take a look. Make sure to take a drive with the tech so you can point out the sound,

 

Melly,
I remember someone posted a thread a few weeks ago about a pinging sound and it was an engine heat shield that was causing the sound. A few others then chimed in that they had the same problem and sure enough, that was the cause.

Hope that helps.