Toyota 1GR-FE

Toyota's 4.0 V6 — the same GR family as the 2GR 3.5, and the engine of the FJ Cruiser, Land Cruiser Prado, GX, Tacoma, Tundra and 4Runner across most of the world.

It is one of the most durable engines in this catalogue, which changes what a fault on one means: a 1GR running badly is very rarely worn out, and the diagnosis belongs in its ignition, its sensors or its emissions equipment.

The one era-specific fault is a head gasket problem on the earliest engines, which Toyota addressed under a service campaign — so on a 2003–2004 vehicle the question is whether the work was done, and on anything later it is not the first thing to suspect.

What arrives with age is ordinary: a brief timing-chain rattle on a cold start as the hydraulic tensioner fills, and valve stem seals that harden and produce a puff of blue smoke after the vehicle has stood. Neither shortens the engine's life on its own, and both are commonly mistaken for something worse on a vehicle that is otherwise running perfectly.