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Hyundai G4NC engine: known problems
Used in 3 guides · 1999cc petrol · 7 known problems
Displacement
1999cc
Layout
I4 NA
Fuel
petrol
Timing
Timing chain (no scheduled belt replacement)
Known problems7
Everything our guides list for the variants with this engine: the engine itself plus the gearbox and ancillaries it's paired with. Each shows which cars it's listed for.
High
Excessive oil consumption / cylinder-bore scoring (GDI)
2013-15 Nu GDI (and 2.4 Theta II GDI) petrols have reported excessive oil consumption (over 1 litre per 1000km) and a knocking/tapping noise, attributed to cylinder-bore scoring where piston skirts contact the bore, opening clearances and letting oil past the rings. Subject of a Johnson Winter Slattery class action against Hyundai in Australia. Less severe than the US Theta failures but a genuine risk.
Fix: Run an oil-consumption test, check service history and warranty/engine-replacement claims; budget for a short-block/engine if consumption is heavy. Avoid examples that knock or burn oil heavily.
Listed for: Hyundai ix35 LM · Hyundai Kona OS
High
Steering-wheel airbag / horn rattle (recall)
Early Series II cars fall within the airbag/horn recall window - the driver's airbag may not be secured and the horn may fail, with a rattle from the wheel.
Fix: Confirm the airbag recall is closed against the VIN.
Listed for: Hyundai ix35 LM
High
Nu piston-oil-ring defect (recall) - oil consumption, knock, seizure/fire risk
Affected 2.0 Nu engines were assembled with piston oil rings of inconsistent heat treatment; excessive ring hardness can chip the ring and scuff the cylinder bore, causing rapid oil consumption, engine knock, oil-pressure warning, power loss and in the worst case a seized engine with a rod through the block (fire risk). This is the basis of the worldwide Nu recall and the Australian Hyundai engine class action.
Fix: Confirm the recall inspection was carried out and the enhanced ECU/Piston Noise Sensing System (PNSS) software is installed; if bore damage is found the engine is replaced. Check oil level and listen for cold knock before buying; avoid any neglected example.
Listed for: Hyundai Kona OS
Medium
Intake-valve carbon build-up (GDi)
Direct injection leaves no fuel wash on the intake valves, so carbon accumulates, causing rough running, hesitation and misfires.
Fix: Walnut-blast or chemical intake clean; quality fuel and disciplined oil changes.
Listed for: Hyundai i30 GD
Medium
Oil consumption / GDi-family engine concerns
Some Nu GDi engines use oil between services. Hyundai/Kia's GDi-family engine reliability (oil consumption, bearing/knock concerns on related engines) drew significant scrutiny and an Australian class-action investigation; the i30's 2.0 Nu is distinct from the recalled 2.4 Theta II but buyers should still verify history.
Fix: Monitor oil; keep records; check the VIN with Hyundai Australia for any outstanding recall/extended coverage. Internal repair if consumption is severe.
Listed for: Hyundai i30 GD
Medium
Direct-injection intake-valve carbon
GDI engines get no port-injection wash of the intake valves, so carbon builds over time, causing rough idle, hesitation and misfire codes at higher km.
Fix: Walnut-blast / intake clean if symptomatic; quality fuel and regular oil changes slow it.
Listed for: Hyundai ix35 LM
Low
Reduced power / transmission clunk on acceleration
Sporadic reports of a clunk when accelerating and occasional hesitation; usually a software/adaptation or mount issue rather than a failed 6-speed auto, which is generally robust.
Fix: TCM software update and adaptation reset; inspect engine/transmission mounts; ATF service if neglected.
Listed for: Hyundai Kona OS
Cars with the G4NC3
From the FlamingCars guides for these cars. Specs are shown only where the guides agree and the value is verified.