Toyota KR (1KR-FE)

Toyota's one-litre three-cylinder — and PSA's, because it is the joint engine of the Aygo, 107/108 and C1 as well as the Yaris, iQ, Mira and Rocky.

That shared parentage is the reason to have this page. A fault documented on a Toyota describes a Peugeot 107 and a Citroën C1 exactly, and their owners are very unlikely to be reading anything Toyota-branded. Establish the engine rather than the badge before dismissing what you find.

It is chain-driven, port-injected and about as simple as a modern engine gets, and it has the reputation to match. What arrives with age is the chain and the water pump, and on high-mileage examples a rattle at start-up that settles with oil pressure is the chain tensioner rather than anything internal.

The 1KR-VET is turbocharged and the 1KR-FE is not — the Rocky and Raize carry the boosted version, and it is a materially harder-worked engine on the same architecture. Oil interval matters more there than the service book's number suggests.