Hi All My turbo has started making the police siren noise. Its not very loud but you can hear it over engine noise etc. Noticable from startup and at tickover and while driving slowly. Car has only done just over 46,000 miles. Its not thrashed although does get a workout when its up to temp now and then. Oil (507.00) and genuine filter changes every 5000 miles and were changed just over 1000 miles ago. Has had a remap a few months ago and done probably between 1000 and 2000 miles since then. No other running or driving issues. Is this something to worry about? Is there something I should check or do?