The last report on the 924S hinted at my thinking that the noise from the engine was coming from a noisy cam follower. Unfortunately this was not the case, with it reassembled the noise was still present. I removed the balance shaft belt and fired it up to see if there was an issue with the shaft and counterweight but this was not the fault either. Yesterday I removed the intake with a view to taking the engine out to investigate further and found the problem, an uninvited guest turned up in the intake tract, found its way into the bore of cylinder number 3 and the piston beat it against the cylinder head creating a fused mass of aluminium on top of the piston. In addition there were to m6 nuts still in the intake, one either side of the throttle, so it looks like someone left some parts under the air filter and they've been making their way through to the engine with somewhat catastrophic consequences.
