One problem related to engine noise has been reported for the 2008 Lexus RX350. The most recently reported issues are listed below.
2008 Lexus Rx350 engine noise started making noise at about 23,000 miles. The dealer said it was normal. Took it back in for the 30,000 mile check up and told them that it was getting louder. They checked it out again and said that it might be the mechanical fuel pump,but that was normal. This is starting to sound like a diesel and is getting a little embarrassing to drive around sounding this way. If this is normal, this will be my first and last Lexus. . . .