Corsa mark

Hi I have had the same problem I own a 68 insignia turbo diesel and I 2020 plate corsa nav premium I have had corsa in garage it came back with no fault code the insignia as so far had new oil pump, nox sensor 1 &2 , chain belts inside engine all changed and still having problems purchased oil from Vauxhall dealer with new filter was coming up with service when already been done