Kia Engines: Common Problems and Key Specs

When it comes to Hyundai-Kia vehicles, we can't help but remember their pretty bad engine karma. A lot of their GDI engines proved to be very unreliable and had so many common problems that I couldn't write a compact article telling you about them. But are all their engines so bad?

In this article, I will tell you about the most popular Kia engines that I've already reviewed on the pages of this blog. They also work under the hoods of Hyundai cars and you will also find a broader article about Hyundai engines.

This page is dynamic and I will update it once I review a new engine of any Kia vehicle. You will also be able to click the links in the sections below and learn more about the engine that you are interested in.

Kia G4KE engine

Used in the 2009-2014 Sorento, this 2.4L engine was used in big Kia vehicles. It's a 4-cylinder engine producing 170-180 horsepower. The construction is pretty conventional. The port injection is very practical yet not really efficient in terms of efficiency and economy.

The engine belongs to the Theta II family. It got phasers on both camshafts, the new intake type. But overall, the engine remained very simple in its engineering. So, it was more or less reliable and quite good to own.

Unfortunately, these engines weren't perfect and could scratch the cylinders because of lubrication problems. Sometimes, rod bearings may be warped because of the same issue. Timing chains aren't very durable and require replacement after 100,000 miles or even earlier.

The G4KE engine can go about 200,000 miles but requires high-quality maintenance.

Key facts and my opinion:

• Production years: 2008-2019
• Average lifespan of G4KE: 190,000-210,000 miles
• Fuel supply type: port injection
• Power range: 170-180 hp
• Fuel efficiency: good
• Engine block material: aluminum
• Engine reliability score: medium
• The most common problems: cylinder warping, weak timing chain, rod bearings premature death, oil leaks.

Kia G4KN engine

The G4KN engine is reviewed by me for the new generation of the Sorento. This is the new-gen 2.5L Samrtstream GDI engine that offers 194 horsepower and quite high torque. Also, the engine has the GDi plus MPI injection systems to avoid carbon buildup on valves.

The head and the block are made of aluminum. Phasers are used on both valves. The camshafts are driven by the chain. This is a non-turbo engine and it has hydraulic lifters for valve adjustment. The G4KN is considered to be quite a simple and reliable machine.

You may require better fuel efficiency from a modern engine though. This engine model is used as the base engine for the Sorento and the Sportage in the North American market. You will get 24 MPG in the city and 29 MPG on highways, but the real-life fuel economy is considered to be worse.

Unfortunately, these engines are not flawless. The most common problem is with the catalytic converter which is located too close to the manifold and can damage the engine if the ceramic filter starts falling apart. Also, the engine has an electronic thermostat which is probably one of the weak links.

Key facts and my opinion:

• Production years: 2019-now
• Average lifespan of G4KN: 180,000-200,000 miles
• Fuel supply type: combined injection (GDI+MPI)
• Power range: 194 hp
• Fuel efficiency: above average
• Engine block material: aluminum
• Engine reliability score: medium
• The most common problems: catalytic converter destroying the cylinders, unknown lifespan of the thermostat, lifters require only good oil.

Kia G4FT/G4FU engine

This is the Gamma-family engine that is used for hybrid powertrains in modern Kia and Hyundai cars. No one can explain the difference between the codes G4FT and G4FU, so I will consider them the same engine with probably some minor and insignificant changes.

This is the 1.6L turbocharged direct injection engine (Smartstream 1.6 T-GDI). The average power is 180 horsepower. The engine is all-aluminum, it has the CVVD valve timing system, and the camshafts are powered by the chain. Surprisingly, it still doesn't have the hydraulic lifters and you will need to adjust the valves manually.

The timing chain is a matter of concern, as in all recent Kia engines. The catalytic converter is located very close to the exhaust manifold and I would be afraid of ceramic debris getting into the engine in case of cat converter damage. Other than that, it's hard to tell you about the common problems with the G4FT/G4FU engine because it's pretty fresh.

Also, this engine can be used with 48V hybrid (mild-hybrid), HEV, and PHEV versions of Kia vehicles. This means it will have different battery packs and various ways to operate the electric engine.

Key facts and my opinion:

• Production years: 2020-now
• Average lifespan of G4FT/G4FU: 130,000-150,000 miles
• Fuel supply type: direct injection
• Power range: 180 hp
• Fuel efficiency: excellent
• Engine block material: aluminum
• Engine reliability score: low
• The most common problems: timing chain issues, catalytic converter too close to the engine block, no lifters.

Kia G6DM engine

This is the Kia 3.3 V6 engine belonging to the Lambda family. It has been produced since 2016 and installed in various Kia and Hyundai models including the Cadenza, Carnival, K900, and also Hyundai Grandeur.

This is the GDI engine - it offers direct injection. It can produce up to 295 horsepower. The chain drives the camshafts, and each of the cams has its own phaser for valve timing adjustment. There are no hydraulic lifters in this engine.

Of course, the G6DM engine is going to have carbon buildup on valves. Also, it's very temperature-sensitive, so you shouldn't overheat the engine in any case. The timing chain has questionable durability but now I can say that it shouldn't start rattling before it reaches about 120,000 miles.

With the estimated durability of 200,000 miles, this is not a bad option to buy. However, the engine requires high-quality maintenance.

Key facts and my opinion:

• Production years: 2016-2024
• Average lifespan of G6DM: 180,000-200,000 miles
• Fuel supply type: direct injection
• Power range: 285-295 hp
• Fuel efficiency: average
• Engine block material: aluminum
• Engine reliability score: medium
• The most common problems: carbon buildup on intake valves, timing chain is weak, no lifters.

GDI engines in Kia vehicles

Also, I've written an article telling you about the GDI technology. There are two types of people: those who hate it and those who love it. The haters say about carbon buildup and unreliable high-pressure fuel pumps. The adorers say that it's fuel-efficient and much more powerful than MPI versions with the same displacement.

I believe it has an equal number of benefits and drawbacks, so it's up to you to decide if you want such an engine. It's going to ask for more minor repairs than a simple MPI engine but it's going to deliver more power to you and burn less fuel when you drive it.

You may read the full article about GDI engines in Kia and make a more informed conclusion.