Engine Overview and Common Failures
The weight of the G4JS engine is 154.2 kg (excluding attachments). The engine number G4JS is located on the cylinder block. The balance belt is responsible for the vibrations of the motor. This engine is demanding in terms of oil quality and especially the intervals for its replacement. Any savings here can lead to jamming of the balance shaft bearings and breaking of their belt, which will then get caught in the timing belt and most likely break it. All this will result not only in bent valves but also in the search for a cylinder head on the secondary market. On specialized forums, there are frequent complaints about strong vibrations of the power unit. The cause may be not only worn-out balance inserts but also weak engine supports. The hydraulic lifters in this engine are sensitive to the quality of lubricants and can fail and start knocking quite loudly at a mileage of 50,000 km. In Kia Sorento, the engine is positioned longitudinally, and the thermostat is in an unfortunate location. Problems with the cooling system are a huge topic on specialized forums. Other drawbacks regularly encountered include oil leaks, fluctuating RPM due to contamination of the MAF, failures in the electrical system, and particularly frequent malfunctions of the CKP, CMP, and ignition timing sensor. On high mileages, piston rings often become stuck, resulting in oil consumption.