Toyota 3Y / 4Y

Toyota's commercial petrol four — the 2.0 3Y and 2.2 4Y — in the HiAce, Hilux, Town Ace and a great many forklifts.

It is an overhead-valve engine built for load and for longevity rather than for output, and it is still in production for industrial use decades after the vehicles moved on — which is why parts remain available when parts for its contemporaries do not.

Its complaints are pre-modern and physical: a carburettor or an early injection system with no useful fault memory, a distributor that fails with heat, and vacuum hoses that harden.

Being a pushrod engine it has no timing belt to schedule — one fewer expensive surprise on a vehicle of this age, and a real advantage over the belt-driven fours around it.

In forklift and generator service it runs on LPG in many markets, which changes the ignition and fuelling diagnosis completely.