Hello everyone. My brother just bought a 2006 Acura TL with 100k miles which drives beautifully without a hiccup except for one thing. The car sometimes makes a strange high pitched metallic drone noise when accelerating. The only thing I can relate it too off the top of my head is the sound high speed trains make when they accelerate or maybe the noise a zip line makes is also similar. It seems other members on this forum have experienced something similar which turned out to be a loose heat shield causing the noise. We did get a pre purchase inspection which revealed a few areas where maintenance is required such as drive belt & tensioner, air filter, left and right lower control arm are worn and a power steering leak but the origin of the noise upon acceleration could not be explained by the technician who said it could be a simple fix or that it could be something major. If anyone could help shed some light on where this noise is coming from that would be greatly appreciated as we have one day to return the car no questions asked if it is in fact something major. Thanks!!!

Here is a video of the noise (you have to turn your volume all the way up to hear it best).

 

Cannot tell you what it is but I would try clamping the heat shields with hose clamps. Most likely the bottom one after the jpipe.

 

Check heatshield over intermediate shaft as well.