The 2.0-liter Hyundai G4KD engine was produced in the USA and South Korea from 2008 to 2014 and was installed on many of the company’s popular models until it gave way to the similar G4NA. Now this motor is assembled at the Hyundai Wia plant in Shandong province for the local market.
In 2008, the Hyundai-Kia concern introduced an updated line of Theta II power units, which included two naturally aspirated engines with distributed injection of 2.0 and 2.4 liters. They were distinguished from the predecessors of the Theta family by the presence of phase shifters on both shafts, as well as a new intake manifold equipped with a proprietary VIS geometry change system. In all other respects, these are the same engines with an aluminum cylinder block, cast-iron liners, an aluminum 16-valve block head without hydraulic lifters and a timing chain drive.
In some markets, a modification of this engine with a single phase regulator was installed, especially often such a unit is found on Kia Forte sedans from South Korea.
Theta 2.0L family: G4KA, G4KD, G4KF, G4KH, G4KL.
The engine was installed on:
- Hyundai Sonata 5 (NF) in 2008 – 2010; Sonata 6 (YF) in 2009 – 2014;
- Hyundai ix35 1 (LM) in 2009 – 2013;
- Kia Cerato 2 (TD) in 2008 – 2013;
- Kia Magentis 2 (MG) in 2008 – 2010;
- Kia Optima 3 (TF) in 2010 – 2013;
- Kia Sportage 3 (SL) in 2010 – 2014.
Specifications
| Production years | 2008-2014 |
| Displacement, cc | 1998 |
| Fuel system | distributed injection |
| Power output, hp | 145 – 165 |
| Torque output, Nm | 190 – 200 |
| Cylinder block | aluminum R4 |
| Block head | aluminum 16v |
| Cylinder bore, mm | 86 |
| Piston stroke, mm | 86 |
| Compression ratio | 10.5 |
| Hydraulic lifters | no |
| Timing drive | chain |
| Turbocharging | no |
| Recommended engine oil | 5W-30, 5W-40 |
| Engine oil capacity, liter | 4.5 / 6.5 (depending on version) |
| Fuel type | petrol |
| Euro standards | EURO 4/5 |
| Fuel consumption, L/100 km (for Hyundai ix35 2012) — city — highway — combined |
10.4 6.4 7.9 |
| Engine lifespan, km | ~300 000 |
| Weight, kg | 124.2 |
Disadvantages of the Hyundai G4KD engine
- The most famous problem with Theta engines is the formation of scuffing in the cylinders due to the ingress of catalyst crumbs from the exhaust manifold into the engine’s combustion chambers. This is followed by progressive oil consumption, and then another piston knock.
- The appearance of abrasive in the engine lubrication system leads to wear of the camshaft journals and oil pump gears, which results in a gradual drop in oil pressure. And this is fraught with cranking of the crankshaft liners at the first serious engine load.
- According to the officials, the timing chain is designed for the entire life of the power unit, but in fact it often stretches on a run of less than 150,000 kilometers. The extended chain often simply jumps and then the valves meet the pistons.
- The weak points of the unit also include weak and ever-flowing gaskets and seals, a low resource of attachments, and in the first years of production also a phase regulator.
