coming home tonight put my foot down at approx 70mph in 6th
no black smoke as usual but instead a hissing sound much like a boost leak
the hissing sound starts at 2500rpm and ends at approx 2800rpm - car 'feels' like its slightly down on power
No fault codes though I have had a plume or two or white smoke - however sat at idle and revving the engine produces NO smoke but the noise is apparent
Got it booked in tomorrow morning but should I fear the worst

Oil and coolant levels seem ok
