Hyundai’s 1.8-liter G4NB engine was produced at the Ulsan plant from 2010 to 2016 and was installed only on a few popular models, such as the Elantra and Serato Forte. In 2013, the production of the engine was transferred to China, where it is installed on the local model Mistra.
Technical specifications
| Characteristics | Value |
|---|---|
| Manufacturing | Hyundai Motor Manufacturing Alabama, Hwaseong Plant, Shandong Plant, Ulsan Plant |
| Engine Brand | G4NB |
| Years of production | 2011 – present |
| Cylinder block material | aluminum |
| Power system | injector |
| Engine type | row |
| Number of cylinders | 4 |
| Valves per cylinder | 4 |
| Piston stroke, mm | 87.2 |
| Cylinder diameter, mm | 81 |
| Compression ratio | 10.3 |
| Engine displacement, cc | 1797 |
| Engine power, hp/rpm | 150 / 6500 |
| Torque, Nm/rpm | 178 / 4700 |
| Fuel | AI-95 and above |
| Environmental standards | Euro 5 |
| Engine weight, kg | 112 |
| Fuel consumption, l/100 km | – City: 9.7; Highway: 5.3; Mixed: 7.0 |
| Oil consumption, g/1000 km | up to 600 |
| Recommended oil | 5W-20 |
| Oil volume in the engine, l | 4.0 |
| Oil change is carried out, km | 15 000 (recommended every 7500) |
| Engine operating temperature, °C | ~90 |
| Engine life, thousand km | – According to the factory data: 200; In practice: ~300 |
| Tuning, hp | Potential: 180; Without loss of resource: 150 |
| Fitted to models | KIA Cerato, Hyundai Elantra, Hyundai i30, Hyundai Mistra |
Service regulations for Hyundai G4NB 1.8 engine
Hyundai G4NB 1.8 liter engine is a reliable gasoline unit with chain-driven timing, focused on long-term operation and optimal performance. To keep it in good condition, it is important to follow the maintenance procedures described below.
| Maintenance item | Periodicity | Volume/Details | Notes |
|---|---|---|---|
| Oil service | every 15,000 km | 4.5 liters (for replacement – 4.0 liters) | Oil 5W-20 or 5W-30 |
| Oil filter | every 15,000 km | – | Replaced at every oil service |
| Air filter | every 45,000 km | – | |
| Fuel filter | every 60,000 km | – | |
| Spark plugs | every 30,000 km | – | |
| Auxiliary belt | every 120,000 km | – | |
| Coolant | every 5 years or 90,000 km | – |
Gas distribution mechanism (GDM)
| Characteristics | Reference |
|---|---|
| Type of timing drive | chain |
| Declared chain life | not limited |
| In practice | about 120,000 km |
| Adjustment of thermal clearances | not required |
| Principle of adjustment | hydrocompensators |
| If the chain breaks/slips | valve bending is possible |
Reliability and repair of G4NB engines
The younger version of the Nu engine lineup first appeared in 2011 on the 5th generation Hyundai Elantra and was designated as G4NB. The installation was a reduced G4NA, which placed a short-stroke crankshaft with a stroke of 87.1 mm (instead of 97 mm on the 2.0-liter counterpart), longer connecting rods, the diameter of the cylinders remained unchanged, respectively, the pistons are almost the same (height 28.5 mm), but the recess in the bottom of the piston a little smaller in the 1.8-liter.
There are no oil injectors on this motor.
On top of the block is the same head as on the G4NA: it’s a 16-valve double camshaft head with D-CVVT on both shafts. The camshafts have the characteristics of 237/235 There are hydrocompensators used here, therefore, valve adjustment is not required. The injection is also no different – it is a typical distributed injection. The VIS intake manifold is similar to its big brother – variable length, two-stage, providing more power in the range of 3000-5500 rpm. It is also made of plastic to save money and weight.
The exhaust manifold is different, with the catalytic converter not as close to the motor as in the G4NA.
The camshafts rotate with the help of timing chain, which is similar to the 2.0-liter engine, is declared as maintenance-free, and behaves the same way. Its resource is not less than 150 thousand kilometers.
Motor control is given to ECU Continental 39105-2EMD4.
In addition to the 2.0-liter G4NA, the Nu series also includes G4NC along with G4ND.
Problems and disadvantages of KIA/Hyundai G4NB engines
- Cylinder scoring
Due to the close proximity of the catalytic converter to the engine block, particles from the catalytic converter can enter the cylinders, causing scoring. This can accelerate cylinder wear and impair engine performance. - Elevated oil consumption (oil build-up)
An aluminum block with thin-walled cast iron liners is prone to deformation, which can cause excessive oil consumption due to cylinder shape (ellipse) disturbance. - Low timing chain life
The thin slat chain used in this engine lasts about 120,000 km. With careful operation, the service life can extend to 240,000 km. A worn chain usually overshoots, leading to valve bending. - Additional drawbacks
Owners often complain about oil and coolant leaks due to weak gaskets, as well as the low life of the water pump and alternator.
If all recommendations are followed, the G4NB engine can go up to 300,000 km, although the manufacturer indicates a resource of about 200,000 km.
G4NB engine tuning
Chip tuning
The market does not offer anything for this engine, so it remains either to customize and try to get +5 hp or do nothing, because 150 forces on the atmospheric 1.8 liters is not bad.
Taking into account that the motor is as close to G4NA as possible, you can try to replace the crankshaft, connecting rods and pistons with 2-liter ones. Putting together your G4NB stroker will give you a torque gain of around 20Nm.
ENGINE RATING: 3+