Whistle noise from engine
 

I have the annoying whistling noise coming from my engine. Regardless of being in Park or Drive, when I step on the accelerator the whistle is there. As soon as my foot is off it stops. I called my dealer and he said it could be the vent valve at the back of the engine. Only a $650.00 part to replace, however he said it should be covered under CPO. I know others have mentioned a tear in the intake tube. I checked and did not see anything. Anyone else have any experience on this subject? Dealer did niot seem certain that it was covered, but I set an appointment to have it checked out. My car is MY 2002 X5 3.0i.

how many miles? when were your drive belts changed? if ever.

72000 miles, not sure if they ever were changed. I have only owned the car since 12/22/05

they are supposed to be changed during the inspection II at 60k

i have the same noise and i'm at 50000

Do a search. Someone else had the same problem and it requires replacing a wobbly wumpet or something.

PCV valve (positive crankcase ventilation valve) is the culprit.
That noise just means it's gonna take a dump at some point. Ignore it if out of warranty until you get a CEL, then replace as its harmless until it breaks for good.
When you turn off the car you hear the valve release pressure and close.
It actually is easy to replace but it's tucked way back against the firewall, hence PITA status. You could order the valve from Crevier for way less than $650 though.
As you're under CPO still just let the dealer do it......