whistling sound noise engine
 

I have 02 3.0 X5 everytime i accelerate i hear this whistling sound in the engine 1st and 2nd gear i think. i just replace my water pump last year, any comments about this... thanks

I have the same problem on my '01 3.0. There is a post somewhere on here that attributes it to a crack in the assembly between the airbox and throttle body. I've been meaning to take care of mine for the last 12 months and haven't, no issues that I can tell except the sound.

Run a search and you should find a solution.