Ford DLD-418 (1.8 Duratorq TDCi)

Ford's own 1.8 diesel — the Duratorq TDCi, descended from the Endura-DI — in the Focus Mk2, Mondeo Mk4, C-Max and Transit Connect.

The thing to establish first is whose engine you are looking at. The same cars were sold with PSA's DV6 1.6 HDi, badged 1.6 TDCi, and the two share nothing: different block, different injection equipment, different faults, different parts. A Focus Mk2 diesel is one or the other, and almost everything written about "the Ford diesel" of that era describes the PSA one, because it was far more numerous.

Its own defining failure is the dual-mass flywheel. It rattles at idle with the clutch up, quietens when the pedal is pressed, and the noise is often chased into the gearbox. On a 1.8 TDCi, a rattle that changes with the clutch is the flywheel until proven otherwise, and it is replaced with the clutch because the labour is the same.

The injection pump and its fuel-pressure regulation are the other recurring items, producing hard starting and a loss of power under load, and the turbocharger's vane actuator sticks with soot. It is an older design than the engines around it — simpler, noisier and, once the flywheel is dealt with, generally long-lived.