My wife has a 2004 RX330 and I've been very disappointed with it. Engine noise/growl on acceleration is very annoying. I thought it was just my imagination... but compared to my daughter's 2002 rx300, it's much louder.....

 

Yeah mine is the same...

The chainsaw-like sound, its normal for these RX's sadly...

 

I've read on one of the forums that the reason for the louder noise was that the intake manifold on the 2004 RX is made of plastic vs aluminum as was previous years. I wonder if anyone have any opinions on that.....

My second question... If indeed plastic intake manifold is the problem, can these be replaced with aluminum ones? What kind of cost are we looking at???