Could be a whistle from the throttle body (air rushing bye when throttle is slightly open).
If no codes are stored and if they can't localize the noise (where it is coming from) it might
be difficult to pin-point what the issue is.
Driving the car with a technician sitting on the radiator grill with the hood open probably
is not a good idea. Driving the car on a dynamometer might work.
Good luck. If I run into the same thing, I'll be sure to post here!
Sunday, October 21st, 2012 AT 2:00 AM