Volkswagen EA111 (1.2–1.6)

The small-displacement petrol family that introduced downsizing to the Volkswagen Group's volume cars, and the origin of the twincharger — a supercharger and a turbocharger on one engine, the supercharger driven from the crankshaft to fill in low-speed response until exhaust flow can spin the turbo. Not every EA111 is twincharged; the single-turbo 1.2 and 1.4 TSI variants are the more common cars.

The timing chain is the defining fault, and the tensioner is the part that fails. A worn tensioner lets the chain slacken, and a slack chain can jump teeth — which on this engine means valve-to-piston contact and a destroyed engine, from a rattle that had been audible for some time. The rattle is loudest on cold start and on shutdown; treat it as immediate rather than as something to monitor.

Piston-ring wear and consequent oil consumption are the second theme, and the two interact — a chain-driven oil pump on an engine low on oil is a compounding problem rather than two separate ones.

⚑ It is a family, and the 1.2 and 1.4 TSI are its best-known members — seven models here carry one or the other. The timing chain tensioner is the complaint that made its reputation, and it belongs to the chain-driven TSI members rather than to every EA111.