Nissan VG (VG30E / VG33E)

Nissan's single-overhead-cam V6 — 3.0 as the VG30E and 3.3 as the VG33E — in the Pathfinder, Navara, Xterra, Quest and Maxima. Its successor is the VQ, which shares nothing with it, so a procedure written for a VQ35 does not describe this engine.

It is belt-driven and it is an interference design. A snapped timing belt bends valves, so the interval is a date rather than a suggestion — and on a vehicle this old the belt's history is usually the single most important unknown. On a cheap example with no records, assume the belt is due.

The VG30E's cylinder heads are its known weakness: valve guide wear and, on earlier engines, head gasket failure severe enough that Nissan extended coverage in several markets. The symptom is coolant loss and overheating in the ordinary way, and by this age the question is whether it has already been done rather than whether it will happen.

The VG33E is the later and better-regarded of the two, and it inherits the belt discipline rather than the head trouble. Both share a distributor that wears and produces a heat-related stumble.