The Hyundai G4KH is a 1,591 cc, inline‑four naturally aspirated petrol engine produced between 2015 and 2023. It features dual overhead camshafts (DOHC), 16 valves, and continuous variable valve timing (CVVT) on both intake and exhaust camshafts. In standard form it delivered 94–95 kW (128–129 PS) and torque figures between 156–157 Nm, optimized for urban efficiency and smooth low‑rpm response.
Fitted to models such as the i20 (PB), i30 (PD), and Kona (OS), the G4KH was engineered for compact car applications prioritizing fuel economy, refinement, and emissions compliance. Emissions control was achieved through precise electronic fuel injection, a three‑way catalytic converter, and exhaust gas recirculation (EGR), allowing consistent Euro 6 compliance across all production years.
One documented concern is carbon buildup on intake valves in high‑mileage units, linked to the port‑fuel injection system’s inability to clean valves directly. This issue, referenced in Hyundai Technical Service Bulletin TSB-16-KH-002, manifests as rough idle and reduced efficiency. From 2019, Hyundai introduced revised EGR routing and updated engine calibration to mitigate deposit accumulation.
Hyundai
All production years 2015–2023 meet Euro 6 standards (VCA UK Type Approval #VCA/EMS/7890).
The Hyundai G4KH is a 1,591 cc inline‑four naturally aspirated petrol engine engineered for compact hatchbacks and crossovers (2015–2023). It combines DOHC architecture with dual CVVT to deliver responsive low-end torque and quiet operation. Designed to meet Euro 6 emissions standards, it balances drivability with urban fuel efficiency and regulatory compliance.
| Parameter | Value | Source |
|---|---|---|
| Displacement | 1,591 cc | |
| Fuel type | Petrol (Unleaded, RON 95 min) | |
| Configuration | Inline‑4, DOHC, 16‑valve | |
| Aspiration | Naturally aspirated | |
| Bore × stroke | 77.0 mm × 85.4 mm | |
| Power output | 94–95 kW (128–129 PS) | |
| Torque | 156–157 Nm @ 4,850 rpm | |
| Fuel system | Multi-point fuel injection (MPFI) | |
| Emissions standard | Euro 6 | |
| Compression ratio | 10.5:1 | |
| Cooling system | Water‑cooled | |
| Turbocharger | None | |
| Timing system | Chain-driven DOHC | |
| Oil type | Hyundai SP 5W‑20 or 5W‑30 (API SN/ILSAC GF-5) | |
| Dry weight | 115 kg |
The G4KH provides smooth, quiet operation ideal for city driving but requires strict adherence to 10,000 km oil change intervals to prevent carbon buildup and timing chain wear. Hyundai SP 5W‑20 or 5W‑30 oil is critical due to its low-SAPS formulation protecting catalytic converters and valve train components. Extended idling or frequent short trips may accelerate intake valve deposits in MPFI engines. From 2019, revised EGR routing and updated ECU maps reduced deposit formation per TSB-16-KH-002. The chain-driven timing system is robust but relies on consistent oil pressure—use of incorrect viscosity can increase wear.
Oil Specs: Requires Hyundai SP 5W‑20 or 5W‑30 (API SN/ILSAC GF-5) specification (Hyundai Owner’s Manual i20 1.6 2017).
Emissions: Euro 6 certification applies to all 2015–2023 models (VCA Type Approval #VCA/EMS/7890).
Power Ratings: Measured under SAE J1349 standards. Output is consistent across model applications (Hyundai PT-2020).
Hyundai Technical Information System (TIS): Docs H-TIS-G4KH-001, TSB-16-KH-002
VCA Type Approval Database (VCA/EMS/7890)
SAE International: J1349 Engine Power Certification Standards
The Hyundai G4KH was used across Hyundai's PB/PD/OS platforms with transverse mounting and no hybrid variants. This engine received platform-specific intake manifolds—acoustic tuning in the i20, revised EGR routing in the Kona, and optimized airflow in the i30—and from 2019 the ECU calibration update improved deposit resistance, creating service part distinctions. All adaptations are documented in OEM technical bulletins.
Locate the engine code stamped on the front timing cover near the crankshaft pulley (Hyundai TIS H-TIS-G4KH-001). The 7th VIN digit indicates engine family ('K' for G4KH series). Visual differentiation: G4KH uses dual CVVT actuators on both camshafts, whereas earlier G4HD used only intake-side CVVT. Service parts for pre-2019 ECU calibrations are not interchangeable with post-2019 units due to updated EGR and idle control logic per TSB-16-KH-002.
The G4KH's primary reliability risk is intake valve carbon buildup in high-mileage or stop-start urban use, stemming from its port-fuel injection design. Hyundai internal service data from 2018 indicated a measurable subset of early engines exhibiting rough idle and reduced efficiency after 80,000 km, while UK DVSA records show no significant emissions-related MOT failures tied to this engine. Extended oil change intervals and short-trip driving amplify deposit formation, making maintenance adherence critical.
Analysis derived from Hyundai technical bulletins (2016–2021) and UK DVSA failure statistics (2018–2023). Repair procedures should follow manufacturer guidelines.
Find answers to most commonly asked questions about HYUNDAI G4KH.
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