Nissan VQ40

The 4.0-litre member of Nissan's VQ family — the engine of the Pathfinder, Navara, Frontier and Xterra, and the truck-duty relative of the VQ35 that sits in the cars.

It shares the family's general durability, and the item most worth knowing is not the engine at all: on a defined range of these vehicles, a failure in the radiator allowed coolant into the automatic transmission cooler circuit, mixing coolant with transmission fluid and destroying the gearbox. It became known as the "strawberry milkshake" failure, and it means a coolant loss complaint on one of these deserves the transmission fluid inspected as part of the same job.

The engine's own recurring items are timing-chain guides at high mileage, the crankshaft position sensor, and — because these are working vehicles — the consequences of dust ingestion where air filtration has been neglected. As with the VQ35, its transverse and longitudinal installations differ substantially in access.