Originally Posted by UNOHOO

all very good ideas but the first thing i thought of was an issue we ran into back in high school when we would install aftermarket radios, sometimes we wouldnt ground something properly and we would get that exact same wiiiiiiiiiii noise and it would go with accelleration, not saying that a stereo is your issue but maybe something isnt grounded right, just a thought

Originally Posted by Mark2008

We began noticing an RPM-dependent high pitch whining noise from beneath the engine, seemingly associated (we hope) with the mesh covering on the exhaust pipe, just downstream from the exhaust manifold. With the engine running at idle in Park, the noise seems to be positional relative to the right side (engine side) of the mesh covering, which I assume is a flex joint. What we hope is that the noise is not associated with engine gel/sludge and that then noise is an engine part screaming for lubrication. Definitely, the noise is loudest beneath the engine, at idle, and increases in pitch with RPM. We do not observe any smoke exiting from the exhaust pipe, nor any check engine light and the temp gauge is at normal, even on a 100F day. I am writing to the Lexus dealer in Eugene to follow this thread.