Nissan RB20 / RB25 / RB26
inline-6 · turbocharged · petrol · 1985–present
Also known as: rb20det, rb20de, rb25det, rb26dett, rb20, rb25, rb26, rb engine, skyline engine
Nissan's straight-six — the RB20, RB25 and RB26 — in the Skyline, Laurel and Cefiro, and in the Maxima and 300ZX in some markets.
The RB26DETT is the GT-R's engine and is the reason most people arrive at this family, but it is a small fraction of the RBs on the road — and almost nothing written about it applies to an RB20DET in a saloon.
⚑ Establish which RB is fitted before anything else. These are among the most swapped engines in existence, and a car's badge is not evidence. The code is cast into the block.
On a standard engine the recurring items are age. The crank angle sensor in the cam-driven distributor housing fails with heat and gives an intermittent cut-out; the ignitor and coil packs are a known set; and the plenum and inlet gaskets leak, giving a lean idle that reads as a fuelling fault.
Oil control is the family's genuine engineering limit, and it is the reason the aftermarket sells restrictors and sumps. On a standard road car it is not the problem; on a modified one it is the first thing to design for rather than the last.
Parts for the RB26 are made; parts for the others increasingly are not, which is often what decides a repair.
Cars fitted with this engine
2 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.
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.
Posted about this engine
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Nothing posted about this yet. Whatever you found is worth writing down — even a dead end saves someone the same afternoon.
What makes one worth reading:
- The car — make, model, year and engine. The same fault behaves differently on each.
- What you measured, not only what you replaced.
- What actually fixed it — or that nothing did, which is worth knowing too.
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