Toyota 2ZR

The 1.8-litre four that replaced the 1ZZ across Toyota's volume range — the Corolla, Auris, Avensis and, in 2ZR-FXE form with an Atkinson cycle and no accessory belt, the Prius. Chain-driven, port-injected on most versions, and with Valvematic continuously variable lift on the higher-output ones.

It is the engine the 1ZZ's oil-consumption reputation should not be transferred to: the piston and ring design that caused that was changed, and the 2ZR is generally regarded as one of Toyota's more durable modern engines. Where it does consume oil, it is usually a piston-ring issue on a specific build range rather than the family-wide behaviour the 1ZZ had.

The hybrid 2ZR-FXE is a different diagnostic proposition from the conventional versions and worth identifying first — it has no alternator or starter in the usual sense, runs on the Atkinson cycle, and a "cranking" or charging complaint on one means something entirely different from the same words on a Corolla. The Valvematic actuator on the FAE versions is the other item, producing rough running and limp behaviour that reads as a throttle fault.