paul, there is allways a certain amount of whistle from turbo engined vehicles but just to set your mind at rest lift bonnet start engine visibly check that all air intake pipes are ok this is easy start at airfilter box and follow them to the engine where they connect to the intake manifold/turbo if when you rev the engine the pipes dont change shape[they appear to be sucked inward]then the whistle is,providing it isnt very loud normal.
by the way the turbo turns at around 100,000 revs which creates a whistle,if any of the pipes change shape then[appear to be sucked in ] then replace that pipe also check your airfilter and make sure its not blocked as this could cause the turbo to work harder for its air supply which could create a whistle good luck m8
alanmellor
June 2006
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix cars.