td5 cutting out at 3,500 rpm

hi , i have a td5 disco that keeps cutting out 3,500 rpm,i have had it on the diagnostics and it has come up with several faults ,being air flow hight fault,hight cranks syncih ,and noisy crank signal detected,i have had the other faults cleared and sorted but it is still doing exactly the same,does anyone know what this could be a result of. any help apriciated thankyou

Crank sensor or damaged crank sensor wiring. They work on very small signals and the wiring often chafes on the top of the bellhousing causing all manner of strange faults.

Has it always done it or is it a recent problem? Make sure if you fit a new crank sensor it is properly shimmed or you'll damage the new one.

well i dont know because its not actuly my car,but the probolem is sorted anyways,thanks for the advice and actuly that was the probolem,i took it out and then cleaned it up and its fine. thanks for the tips mate apriciated !

check waste gate valve. It is easy to check.

If it had fillings on it then the flywheel is failing causing your issue