eds97c280

i recently started to hear a strange noise from my engine bay. it comes and goes. it sounds like a high pitched whistle. i believe it sounds when the fan kicks on?? i recently had a major tune up at the dealer and they replaced the water pump,pulley and belts as well. before that i had the fan clutch replaced. anyone ever have this happen to them?

linuxfoo

i hear a slight whizzing noise in both my c43 and my wifes c280 when i start the car in the monring and its the aux air pump i believe, i only hear mines when my car is not warmed up enough. you shouldn't hear the sound once the car is fully warmed up.