Hyundai 2.4 Engine Problems – Is The 2.4 Theta Engine That Bad?

Hyundai 2.4 Engine Problems – Is The 2.4 Theta Engine That Bad?

January 14, 2024 0 By CarGuy

Are you looking to purchase a Hyundai with the Theta engine and want to learn more about the Hyundai 2.4 engine problems? If that’s correct, look no further because, in this article, there will be a lot to cover on this topic.

Doing your own research on the problems that you might face when buying a used car is always a good idea. Cars come in a variety of configurations and each of these configurations performs differently. Some engines are good, while some are pretty bad and can be very expensive to fix. And that’s why we are here to help you out.

First, we will cover the specs of the 2.4 engine, as well as the applications. Then, we will discuss the Hyundai 2.4 engine problems and reliability. So, without further ado, let’s dive into the article.

Basic Hyundai 2.4 Engine Specs

The Theta engine is a family of engines produced by Hyundai since 2004. This family of engines has the original Theta and the Theta II engines.

There are different displacement engines in the Theta family, but we are primarily interested in the 2.4L engine for this article.

The 2.4 is the largest displacement Theta engine. In general, this is an inline-4 made from an aluminum block and aluminum cylinder head.

The head is DOHC with four valves per cylinder, two for the intake and two for the exhaust.

What is interesting about the Theta 2.4 is that this engine comes with port injection and direct injection. Port fuel injection engines are known as MPI, while direct injection engines are known as GDI.

There is also a 2.4 engine made to run on LPG gas, also known as autogas.

So, we can say that this engine came in a variety of different configurations. More on that, we will cover in a bit when we will discuss the applications of the 2.4 engine. Now let’s share the specs of the 2.4 engine.

  • Configuration: inline-4
  • Displacement: 2.4L
  • Bore: 88 mm
  • Stroke: 97 mm
  • Block & Head Material: Aluminum
  • Head Design: DOHC, 4 valves per cylinder
  • Fuel Injection: Port or Direct Injection
  • Aspiration: Naturally aspirated
  • Horsepower: 163 – 200 hp
  • Torque: 161 – 183 lb-ft (219 – 250 N-m)

Hyundai 2.4 Engine Applications

Now let’s take a look at the applications of the 2.4 Theta engines and learn more about the cars that include this engine.

2.4 Theta I (G4KC)

  • 2004 – 2007 Hyundai Sontata NF
  • 2005 – 2007 Hyundai Grandeur TG
  • 2005 – 2008 Kia Optima MG
  • 2007 – 2008 Kia Rondo

2.4 Theta II MPI (G4KE)

  • 2007 – 2019 Hyundai Sonata
  • 2010 – 2020 Hyundai Santa Fe
  • 2008 – 2011 Hyundai Grandeur
  • 2013 – 2016 Hyundai Azera
  • 2010 – 2020 Hyundai Tucson/ix35
  • 2008 – 2019 Kia Optima
  • 2009 – 2019 Kia Cadenza
  • 2008 – 2012 Kia Forte
  • 2008 – 2013 Kia Rondo
  • 2011 – 2021 Kia Sportage
  • 2009 – 2020 Kia Sorento

2.4 Theta II GDI (G4KJ)

  • 2009 – 2019 Hyundai Sonata
  • 2011 – 2019 Hyundai Grandeur/Azera
  • 2015 – 2020 Hyundai Tucson
  • 2012 – 2020 Hyundai Santa Fe
  • 2010 – 2019 Kia Optima
  • 2010 – 2021 Kia Sportage
  • 2014 – 2020 Kia Sorento
  • 2011 – 2019 Kia Cadenza
  • 2016 – 2021 Kia KX7

2.4 Theta II Hybrid (G4KK)

  • 2013 – 2022 Hyundai Grandeur/Azera
  • 2013 – 2021 Kia K7/Cadenza
  • 2.4 Theta II LPG (Autogas) (L4KB)
  • 2008 – 2021 Hyundai Starex

Hyundai 2.4 Engine Problems

Now let’s discuss the problems with the Hyundai 2.4 engine and learn what troubles these engines the most.

  1. Carbon Buildup
  2. Rod Bearing Failure
  3. Oil Consumption
  4. Head Gasket Failure
  5. Timing Chain Slack
  6. Oil Leaks

We learned what are the common Hyundai 2.4 engine problems, and now let’s elaborate more in-depth on these problems.

This is crucial in order for you to have a better grasp of knowledge and understand these problems in detail and how serious they are. So, let’s get started.

1. Carbon Buildup

The first problem on our list is carbon buildup. So, what is carbon buildup and why does it occur in cars?

Carbon buildup is carbon deposits that accumulate in the engine. Specifically in this case, on the intake ports of the engine.

The intake ports are the ports where the intake valves are located. So, why it is a problem?

Well, this is a problem with Hyundai engines that use direct injection. In other words, the GDI version of the 2.4.

This engine uses a special injector for direct injection and does not use the standard method of injecting fuel through the intake ports.

This allows the oily vapors to accumulate on the valves and prevent them from opening and closing correctly.

This situation can lead to engine misfires and loss of compression. The only way to fix a problem like this would be to rebuild the cylinder head.

However, you can prevent this by doing a method known as walnut blasting every 60,000 miles. With this method, walnut shells are blasted in the engine and these shells destroy the carbon deposits, leaving the valves nice and clean.

It can cost some money but it is a good idea to clean up your engine from carbon buildup.

Now let’s move on to the next Hyundai 2.4 engine problems.

2. Rod Bearing Failure

Another very common problem with these engines is rod bearing failure. So, what is a rod bearing and why does it fail?

Well, a rod bearing is the bearing that sits between the rod and the crankshaft. These bearings basically serve a good purpose, which is preventing friction and allowing the pistons to move up and down.

What is bad is that these bearings are notorious for failing. Especially on the Theta II engine, they can wear out and allow the engine to knock.

This situation is known as a rod knock. This problem will eventually cause the engine to seize completely.

This problem reportedly has a lifetime warranty by Hyundai according to some owners on the Hyundai forums.

Which says that for any rod bearing failure, they will give you a new engine. This is good considering the fact that these bearings fail often on these engines.

However, we would recommend that you do your maintenance on the engine and top of the engine oil regularly in order not to make the engine starve from oil.

3. Oil Consumption

Another very common cause for accelerating rod bearing failure is the excessive oil consumption that these Theta II engines suffer from.

These engines, especially at miles higher than 100,000 tend to drink a lot of engine oil. And many owners are unaware of this.

They take their Hyundai or Kia to the shop to do their maintenance and the car has a few quarts less oil and this oil has turned into a sludge.

This oil is full of carbon deposits that damage cylinder walls and bearings in the engine. Which leads to rapid engine wear.

And eventually, the engine will seize. This is why you need to track the engine oil level when it comes to these Theta II engines.

Make sure that you have the right level of oil and also do more regular oil changes. Let’s say every 8,000 miles. This way you will prevent dirty oil from damaging the bearings in the process.

Preventive maintenance will save you thousands of dollars when it comes to these engines.

Now let’s move on to the next Hyundai 2.4 engine problems.

4. Head Gasket Failure

Since the lubrication system of this engine is not one of the best and is constantly clogged up with dirty oil and deposits, this means that the engine is not good at dissipating heat.

The oiling of the engine is not only to lubricate but also it helps to dissipate the heat a bit better. So, when you have such an engine, it is very easy to overheat it.

When the engine overheats, it will blow a head gasket. The head gasket is the gasket that is placed between the cylinder head and the deck of the block.

This is the most common failure point when you have overheating. When this happens, you know that you will need to resurface the cylinder head in the process because it is warped.

This should be done at a machine shop and can cost you a good penny to bring the engine back to normal.

So, watch the temperatures along with the oil level in order to prevent overheating issues on this Theta engine.

5. Timing Chain Slack

These Theta II engines use a timing chain. This timing chain has the role of keeping the top and bottom portions of the engine in perfect sync.

Whenever there is slack and the chain starts to wobble, you will experience engine rattle. This rattling sound will be most excessive at low rpm.

What is bad is that when this happens, you will need to replace the timing chain with a new one. If you delay the service, the chain could possibly jump and ruin the engine.

In this case, valves and pistons will collide and engine damage will occur, which will scrap the engine in most cases.

6. Oil Leaks

Oil leaks are also pretty common on these engines. Oil leaks can occur from different places. Specifically, these engines can leak from the oil pan and oil drain bolt because of a faulty drain plug.

Other places where you can get leaks include the valve cover, timing cover, and front and rear main seals.

Overall, try to avoid these leaky engines because in most cases, they are associated with poor maintenance and the lack of interest from of the previous owner to fix these leaks.

Hyundai 2.4 Engine Reliability

The overall reliability of the 2.4 Theta is slightly below average.

These engines do not last very long. They consume oil above 100,000 miles and when you have such an engine you know that it’s nearing the end of its lifespan.

When you browse the longest mileage 2.4 Theta, you will find a few people who have reached the 124k milestone, some reaching 150k. But overall, this is the max for these engines from the experiences we’ve read.


In this article, we covered quite a bit when it comes to the 2.4 Theta engine by Hyundai. We learned the specs and applications of this engine.

In the following part, we discussed the most common Hyundai 2.4 engine problems and reliability.

Overall, this engine has problems with oil consumption and rod bearing failure. Its lubricating capacities are not some of the best and will highly likely not last for 200,000 miles.


What are the key specs of the 2.4 Theta engine?

This engine is a 2.4L inline-4 made from aluminum block and aluminum head. Implements DOHC head layout with two camshafts. There are versions with port injection and direct injection. The engine only comes as naturally aspirated.

Which models have the 2.4 Theta engine?

This engine was included in a lot of Hyundai and Kia applications since 2004. This engine was most commonly included in the Hyundai Sonata and Kia Optima. But there are many other models which include the Hyundai Santa Fe, Hyundai Tucson, Kia Sportage, Kia Cadenza, and others.

What are the common Hyundai 2.4 engine problems?

Common problems with this engine include oil consumption and rod bearing failure. This engine has a poor lubrication system and can consume a lot of oil, if deprived of oil, it will wear the rod bearings and cause rod knock. Which eventually will lead to seizing and engine failure.

Is the 2.4 Theta engine reliable at all?

At low miles is reliable but when miles start to accumulate it is very unreliable and prone to failure. Specifically, above 100,000 miles, the reliability is somewhat dubious and you never know when you will be required to replace or rebuild the block. Especially if it already started to consume serious amounts of oil.

If you want to read more on car problems, you can check our article on the GM 2.4 engine.