Idle clatter and belt squeal in Transit 2.0 TDCi - crankshaft pulley

A metallic clatter at idle that disappears when the throttle is blipped, plus belt squeal despite a good tensioner, are classic symptoms of a delaminating crankshaft pulley on Transit MK6 2000-2006. The pulley is a two-piece design with a rubber torsional vibration damper. With age, the rubber hardens, cracks and comes unstuck, and the outer ring begins to run sideways. A characteristic warning sign is pieces of rubber sticking out around the pulley edge.

Can you drive with a delaminated crankshaft pulley?

It is not worth the risk. Without damping, crankshaft torsional vibrations transfer to the belt and accessories, prematurely damaging the alternator, power steering pump and tensioner. In the worst case, the outer ring separates completely from the hub and, spinning at high speed, can destroy the radiator and hoses in the engine bay. The darkest scenario is fatigue cracking of the crankshaft. When replacing the pulley, always fit a new central bolt tightened by torque plus angle, and replace the belt and rollers at the same time.