ChrisYL 
2009 Toyota Sienna Minivan LE 8-Passenger 4dr Minivan (3.5L 6cyl 5A)
Good Minivan But Engine Humming Noise
 Bought my 2009 Sienna LE in Dec 2008 in Orange, CA.  Everything is good, drive smooth, roomy, comft.  However shortly after driving, I start to hear engine humming noise, sometimes loud, sometimes not there.  Happening specially at acceleration.  My friend's 2007 has similar problem, others on Edmunds Discussion site mentioned same problem.  Any of you seen this problem?