2021-2024 KIA Sorento 2.5L Non-Turbo Base Engine (G4KN): Longevity, Problems, and Specs

In 2023, one of the best budget-friendly family SUVs is undoubtedly the KIA Sorento. The vehicle is pretty cool in terms of quality, ride comfort, technologies, and space inside. The Sorento comes with 3 rows of seats still remaining a relatively small SUV. So, it will combine such advantages as a lot of seating places and more or less optimal fuel consumption.

Today, we will focus on the 2023 KIA Sorento 2.5L 4-cylinder base engine (G4KN) that powers the majority of the Sorento SUVs sold in the US currently. We'll see if this engine is a good choice for you or if you should opt for any other engine in the lineup of the Korean manufacturer. Believe it or not, we love this engine and there are several reasons why we would choose it instead of a more technological option.

Key facts and my opinion about the engine

• 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.

What should you know about the non-turbo 2.5L engine in the Sorento?

KIA did a great job and offered wonderful engines for the new generation of the Sorento. The main and base engine is the 2.5-liter Smartstream GDI engine which is the most popular in the US. But there is also the 2.5-liter 4-cylinder turbo engine with much more power and torque. Also, the Sorento is available as a Hybrid and a plug-in Hybrid which makes your choice quite difficult.

But if you want a family SUV that costs about $30,000, the choice comes down to the base non-turbocharged engine that offers 2.5 liters of displacement and 191 horsepower. We should be fair with you - it's not the power you will be proud of. But this power is completely enough to drive with pleasure.

Here are some facts you should know about this engine:

• this is a naturally aspirated engine, it doesn't have any turbocharger which may be a pro or a con depending on your expectations and beliefs;
• the engine is coupled with an 8-speed automatic transmission which is not bad in terms of quality and durability;
• the engine has the direct fuel injection system (GDI) which makes it more powerful and more economical than a non-GDI version that is not presented in the US;
• this engine is all-aluminum - this is common for nearly all engines currently, so nothing to talk about here;
• the timing system is driven by the chain - it may bring some problems in the future, but now no issues have been registered;
• the engine was first introduced in 2019, so it's quite a new unit and we still don't know much about its common problems;
• overall, the engine is quite technological, although it may seem like a simple technology with nothing to worry about, it's not completely true;
• the engine is pretty economical with 29 MPG on highways and about 24 MPG in the city which is great gas mileage.

Well, not a lot is known now about the engine because not many of them have hit at least 100,000 miles to give some statistics about its issues and weak spots. But still, this is the engine that is based on the highly technological Smartstream technology developed by Hyundai and KIA. Actually, nearly all gasoline engines of these brands now belong to the Smartstream family.

So, now we know that the 2.5L 4-cylinder non-turbocharged engine in the KIA Sorento is quite good in terms of technologies, gas mileage, driving emotions, etc. This engine can help you speed up the new Sorento quite fast and not to worry about overtaking somebody on narrow highways.

What about the durability of the engine?

The G4KN engine in the Sorento should be really good in terms of longevity. But still, we don't know how long it can last because no one has yet broken the engine or driven over 200K miles to make any certain conclusions. But given we know the history records for other Smartstream engines and overall KIA-Hyundai units, we can make some presumptions that should be of some use to you.

So, any naturally aspirated KIA engine should last over 150K miles and we believe the 2.5L Smartstream is no exception. This engine is pretty technological though, and we should say that Hyundai-KIA has never built such a complicated naturally aspirated engine. It means that some surprises may be on the way and you may not like them.

Still, we think the average lifespan of the 2.5L non-turbo engine in the KIA Sorento should be about 180,000 - 200,000 miles. Of course, the durability of your engine depends much on how well you maintain it, what kinds of parts you buy, etc.

What are some possible common problems with the 2.5L Sorento base engine?

So, here we come to one of the most interesting parts where we'll try to guess which problems are going to happen with your engine after you drive a lot of miles. Of course, this article will be especially needed in a couple of years when these Smartstream engines start to fail. But we believe someone will want to know more about the engine before they pay their money.

So, here are some of the common problems we are sure will happen with the 2.5L 191-horsepower KIA engine in the Sorento:

1. Carbon deposits on valves

Even though the engineers introduced the double-row injection system, this will not completely solve the carbon deposit problem. The engine is still going to get clogged with carbon deposits after it goes more than 100K miles.

This is not a major problem and it can be solved just by cleaning the valves. The problem is the price - you will certainly hate the idea to pay several hundred dollars just for cleaning the valves.

2. Catalytic converter issues

The car converter is pretty conventional here but it's placed very close to the engine block. It means that the ceramic debris can easily get to the cylinders when the converter begins to break down. This process happens all the time, so some ceramic dust may get to the cylinders very soon after you buy your vehicle and this will cause scratches on the cylinder walls.

This is a very common problem for all Hyundai-KIA engines, even the older ones. But it has to be considered. If you suspect the catalytic converter is dying slowly, better replace it before it starts failing and falling apart.

3. New type of thermostat and oil pump

We don't know if this problem will occur but we want to warn you. The new electronic thermostat is very efficient and can adjust to certain conditions your engine works under. But we can't even guess how long it will work. We feel this is one of the weak points of the engine.

Also, the new adjustable oil pump may be the source of other issues. If it fails, the oil will not be pumped to all parts of the engine and the whole unit will fail and need replacement. It's the worst-case scenario, but new technologies have to be reckoned with. Just keep an eye on those things.

4. Hydraulic lifters are really demanding in terms of oil

The fact that this engine has hydraulic lifters is good - you won't need to pay for having your valves adjusted. But the fact that these lifters are extremely demanding in terms of the quality of the oil is not that good.

If you use any other oil but the one recommended by the manufacturer, the lifters may soon fail and cause problems. They may make bad sounds or just kill the valves. So, this is one more important thing to pay attention to.

How should you maintain your 2.5L Sorento engine?

The only good description in this section should be this: see the owner's manual. This is the religion for any Hyundai owner, so just keep up with all the maintenance requirements KIA writes about in this interesting book.

Don't buy any other oil but the recommended one. And don't experiment with other parts. This engine is pretty technological and complicated and it won't be glad if some inexperienced mechanic will repair or maintain it. The new Sorento is certainly not the vehicle for those who want to save some money and buy cheaper parts.

Final words

You should understand what you are buying. That's why we spent a lot of time investigating everything the internet knows about the 2.5L Smartstream engine that you will find in the base version of the KIA Sorento in 2023 and probably some following years. And we think this engine is not bad at all.

The engine is pretty powerful, it offers good torque, it's very economical, and it's not going to die soon. But still, some potential problems should be considered before purchase.