Nissan QG18DE (QG family, 1.6 and 1.8)

1.8 L · inline-4 · naturally aspirated · petrol · 1999–present

Also known as: qg18de, qg18, qg16de, qg15de, qg engine, 1.8 nissan

Nissan's 1.8 four — in the Primera, Sentra, Almera and Bluebird Sylphy.

It replaced the GA family and is an all-aluminium, chain-driven design with variable timing on the intake — a modern engine where the GA was a simple one.

⚑ Its known problem is the timing chain, and specifically the tensioner and guides. The symptom is a rattle for a second or two on a cold start, worsening over months, and it is genuinely worth acting on: a chain that jumps on this engine is an interference failure.

Carbon on the intake and throttle body is the other recurring item and produces a hunting idle and a hesitant pull-away, particularly on cars used for short journeys. It responds to cleaning rather than to parts.

Ignition coils fail one at a time and give a misfire under load before they give one at idle, which is the ordering worth knowing when a customer reports a fault that only appears on a hill.

The QG16DE and QG15DE are the same design in smaller sizes. The QR family that followed is a separate engine with its own page here.

Cars fitted with this engine

3 generations, across 1 make. From the authored catalogue — an absent car means the catalogue has not reached it, not that the engine was never fitted.

Nissan

Information, not instruction

CarGeek is a reference, not a service manual. Its pages are written from public sources and from what other people have found, never from a manufacturer's own service information, so they can be wrong or incomplete for your particular vehicle. Some of what they describe carries real risk: high voltage, fuel under pressure, stored energy, hot and moving parts.

Have anything you intend to act on checked by a trained person against the manufacturer's own procedure for your vehicle. Nothing here replaces that procedure.

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The car — make, model, year and engine. The same fault behaves differently on each.
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