What changed from Theta to Theta II
The G4KA (2004–2007) is an aluminium-block, chain-driven 16-valve 2.0 with continuously variable valve timing on the intake side only, rated at about 144–151 PS. The G4KD keeps the displacement and bore and stroke but adds CVVT on the exhaust side and a two-way variable intake system, which lifts output to about 165 PS.
Both are multi-point-injection engines. The Theta II recalls in the United States concerned the direct-injection Theta II engines, not the MPI G4KD, and the G4KA predates them.
| G4KA | G4KD | |
|---|---|---|
| Family | Theta (first generation) 2.0 | Theta II 2.0 MPI |
| Displacement, bore × stroke | 1,998 cc, 86 × 86 mm | 1,998 cc, 86 × 86 mm |
| Variable valve timing | CVVT on the intake camshaft | Dual CVVT (intake and exhaust) plus two-stage VIS |
| Typical output | About 144–151 PS | About 165 PS |
| Typical vehicles | Sonata NF (2004–2007), Optima / Magentis MG (2005–2007), Carens UN | Sonata (2007–2014), Tucson ix35 LM (2009–2015), Sportage SL (2010–2013), Forte/Cerato TD, Optima (2008–2012) |
| Published price (per unit, FOB, full container) | US$ 450 | US$ 500 |
| Matching gearbox (mixed configurations only) | US$ 170 | US$ 120 |
Are the G4KA and G4KD interchangeable?
Not as a like-for-like swap. The blocks share dimensions, but the head, the exhaust-side cam phaser and the intake system differ, and the engine control unit of each car is calibrated for the engine it left the factory with. Stock the model the car carries: G4KA for the early Sonata NF and Optima/Magentis, G4KD for the facelifted Sonata onward, the Tucson ix35 and the Sportage SL.
Because the model name alone is not enough, ask your customers for the engine model stamped on the block. The photos in your order file show the engine code or identification plate where it is visible on each engine.
Which one to weight a container toward
The G4KD follows a larger and younger vehicle population — Tucson, Sportage, Sonata and Optima 2.0 — so it is usually the volume model, with G4KA added for counters that still serve the early Sonata NF and Magentis fleets. Our check is the same for every engine: cleaning, handling, a manual crankshaft rotation with a tool to confirm the mechanism turns, and photos from every side, delivered to you as an order file — Engine 1, Engine 2 and so on. It is not a compression, leak-down, bench or running test, so it does not prove how an engine will run once installed. You don't need to travel to buy, but you or your representative are welcome to visit for a Guangzhou Inspection Day and review your prepared lot in person, with a USD 1,000 visit deposit credited to your order.
A 20-ft container takes 90 engines and a 40-ft 130, Grade A only, and any of the nineteen published models can be mixed. The companion guide G4KD vs G4KE covers the 2.4-litre Theta II; build the mix on the quote page.
Sources
- Hyundai Theta engine — Wikipedia (specifications, years and applications)
- ENGICOR prices and terms: our own published list, recorded monthly in the used engine price index.
Price a container yourself
Build the mix you want in the online quoter — 90 engines in a 20-ft or 130 in a 40-ft, or 45 + 45 / 65 + 65 with gearboxes — and the FOB total reaches your inbox the same minute, at our published per-unit prices, every engine Grade A. Prefer to ask? Tell us the destination country and the models you need and we reply within one business day, usually within hours.
Frequently asked
What is the difference between the G4KA and the G4KD?
The G4KA is the first-generation Theta 2.0 with intake-only CVVT, and the G4KD the Theta II 2.0 with dual CVVT and a two-stage variable intake; both are 1,998 cc with 86 × 86 mm bore and stroke.
Which cars use the G4KA engine?
The G4KA was fitted to the Hyundai Sonata NF (2004–2007), the Kia Optima/Magentis MG (2005–2007) and the Kia Carens UN.
How much are a used G4KA and G4KD at ENGICOR?
The G4KA is US$ 450 and the G4KD US$ 500 per unit, FOB, inside a full container of 90 (20-ft) or 130 (40-ft) engines, Grade A only.