MartinWillmott

Mine sounds a bit like a manifold blow but it isn't, apparently there's a small plug in the end of the camshaft which falls out lowering the oil pressure at that end of the camshaft, this results in a flat spot wearing on an exhaust cam so the valve clearance on that valve is wrong causing that one cylinder blow sound, its a sort of deep cough on idle just like an exhaust blow but on one cylinder, not severe but not a healthy sound.