12v whining noise

[mike_stout_]

hi guys
ive got a corsa 12v and its making a whining noise almost like its supercharged and if i leave it about 1 minute the oil light flickers any ideas?
thanks in advance.also it lacked power/held back and the whining got louder but im pritty sure the clutch wasnt slipping.

[octane41]

if its a whistling then prob an air leak.

check the vaccum pipes for leakes - could be the inlet manifold gasket that needs replacing.