Mitsubishi 4G3 (4G32 and 4G37, 1.6 and 1.8)
1.8 L · inline-4 · naturally aspirated · petrol · 1985–present
Also known as: 4g37, 4g32, 4g33, 4g36, 4g3, 1.8 mitsubishi
Mitsubishi's 1.8 four — the 4G37 — in the Galant and the first Eclipse.
It is the plain engine in cars remembered for something else. The Eclipse's reputation belongs to the turbocharged 4G63; this is what the base cars had, and almost nothing written about that car applies to this engine.
It is a belt-driven, single-overhead-cam design with balance shafts — Mitsubishi's own patent, licensed to half the industry — and those shafts are the item worth knowing about: the balance shaft belt is separate from the timing belt, it is rarely changed, and when it fails the debris can take the timing belt with it. On any engine of this family, ask whether both belts were done.
Its running complaints are pre-modern: a tired idle speed control, vacuum leaks, and a distributor whose failure is heat-related and intermittent.
The 4G63 has its own place in this catalogue and shares the architecture but nothing of the reputation, the parts prices or the tuning.
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
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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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