Theta is a gasoline four-cylinder Hyundai engine family. The first generation of Theta engine has two variants 2.0L and 2.4L. The second version also has two variants such as 2.0L(G4KD) and 2.4L(G4KE). Theta second generation is popular for issues among all types of engines. This is a widely used engine in Hyundai, Kia cars especially in Sonata, Santa Fe, Kia Forte, Kia optima models.
Having said that, Theta II engines are famous for problems, it causes knocking, stalling, and potential fires in the Hyundai Sonata (2011–2012 version). These problems made the South Korean automaker to recall 470k Sonata cars in 2015. The engines are ‘Gasoline Direct Injection’ which is the first to come out of the Hyundai Alabama Plant. After a long time, the automaker admitted that the metal debris during crankshaft machining was not removed completely and machining error on crankpins was the reason for drawbacks. This caused them to increase warranty for the engine block to 10 years/120,000 miles for the affected cars.
In 2017, Kia recalled more than 672k vehicles and Hyundai made a call back to Sonata and Santa Fe sport vehicles. NHTSA made an open investigation in the recalls. In 2018, Centre for Auto safety came up with a list of vehicles that has to be taken off from the road until the pending investigation ends with recall. About 1.7 million cars have been recalled since 2018, CAS announced that need to investigate more to assure the safety of consumers.
The year 2019 also not a good one for Theta II engine manufacturers. They can’t control the replaced engine fires. The saddest part is that recalling the recalled vehicles. Again, it recalled nearly 1,00,000 engines with the problem in fuel tube installation. It covers Sonata (2011–2014) and Santa Fe (2013,2014).
These problems reminded the fact that ‘’ One small mistake may lead to huge loss’’. Eventually, Hyundai is hardly trying to overcome those defects.
