Cheers guys,

Steve, I was wondering if a compression test could be done without turning the engine over ? eg remove all the cams so the valves are closed and inject air under pressure via the plug hole and measure when air leaks start to happen or something along those lines.

Whitneyd, to be honest, I wasn't looking at the cams when I tried, but it sounded exactly like it does when a belt has snapped - it whirred but there was no other mechanical noise.

Anyone got a compression tester I can borrow ?