Mazda K-series V6 (KL / KF / J5)

Mazda's small V6 — the 1.8 KF, 2.0 KL and 2.5 J5 — in the 626, MX-6, Xedos, Millenia and the 929.

⚑ A 1.8-litre V6 is an unusual thing and the family's defining oddity: six very small cylinders, twenty-four valves and two cylinder heads in a car that would elsewhere have a four. Everything is harder to reach than the displacement suggests, and the rear bank is against the bulkhead.

It is belt-driven and it is an interference design, and on a transverse V6 the belt job is what decides whether one of these cars is worth keeping.

Its recurring complaints are ignition and breathing: coil packs, a carboned throttle body, and inlet gaskets that harden and leak unmetered air, giving a lean idle that reads as a fuelling fault.

The Millenia's supercharged KJ-ZEM is a Miller-cycle engine and a genuinely different proposition — one of very few ever sold — whose diagnosis shares little with the rest of the family.