Hyundai 1.8 Nu Engine Problems – 3 Worst Problems!

Hyundai 1.8 Nu Engine Problems – 3 Worst Problems!

February 1, 2024 0 By CarGuy

Are you looking to purchase a Hyundai with the 1.8 Nu engine and want to learn more about the Hyundai 1.8 Nu engine problems? If that’s correct, you should look no further because, in this article, there will be a lot to cover on these issues.

Doing your own research on a particular engine is always a good idea. Cars come in a variety of configurations and different engines. All of these engines perform differently and have different problems. So, learning more about these issues is always a good idea. And that’s why we are here to help you out.

First, we will cover the specs of the 1.8 Nu engine, as well as the applications. In the second part, we will discuss the Hyundai 1.8 Nu engine problems and reliability. So, without further ado, let’s dive into the article.

Hyundai 1.8 Nu Engine Specs

The 1.8 Nu engine is an engine produced since 2010. This engine belongs to the Hyundai Nu family of engines. In general, the Nu family is an engine with a displacement of between 1.8L and 2.0L.

Specifically for this article, we are interested in the 1.8L version of the Nu engine. This engine is also known under the codename G4NB.

In general, the 1.8L is an inline-4 engine that is naturally aspirated. This engine comes with port injection and dual variable valve timing.

Overall, the design is very simple of the 1.8L engine and doesn’t have the complexity of other engine families by Hyundai such as the Theta that we previously covered.

So, what this means is that the 1.8L is a really easy engine to work on and if you are a beginner who is starting wrenching, this is a very easy engine type to deal with. Both in terms of maintenance and repair.

Nevertheless, here are the most important specs of this 1.8L engine.

  • Configuration: inline-4
  • Displacement: 1.8L
  • Bore: 81 mm
  • Stroke: 87.12 mm
  • Block & Head Material: Aluminum
  • Head Design: DOHC, 4 valves per cylinder
  • Fuel Injection: MPI
  • Variable valve timing: Yes, D-CVVT
  • Aspiration: Naturally aspirated
  • Horsepower: 143 – 148 hp
  • Torque: 129 – 131 lb-ft (175 – 178 N-m)

Hyundai 1.8 Nu Engine Applications

Now let’s take a look at the applications of this 1.8 Nu engine.

  • 2010 – 2015 Hyundai Elantra
  • 2011 – 2017 – Hyundai i30
  • 2014 – Present Hyundai Mistra
  • 2014 – 2021 Kia K4
  • 2013 – 2016 Kia Forte

Hyundai 1.8 Nu Engine Problems

Now let’s list the common problems with the Hyundai 1.8 Nu engine.

  1. Oil Consumption
  2. Rod Bearing Failure
  3. Piston Slap/Ticking Sound

We learned the most common problems of the Hyundai 1.8 Nu engine. Now let’s dive deeper into each one of them and further understand these issues.

This is a recommended thing since you need to learn what to expect. In other words, the circumstances of how these issues develop and how serious these problems are. So, let’s cover them in detail.

1. Oil Consumption

The first problem on our list is the oil consumption. This is a common problem with Hyundai engines from the Nu and Theta families.

These engines tend to consume a lot of engine oil when they reach 80,000+ miles on the odometer. Cases might vary but the overall estimate is this.

These engines were poorly designed and they were not meant to last for a very long time. Oil consumption is one of the leading factors to engine failure.

This is the case because whenever you have oil consumption, you have engine wear and the more consumption there is, the more wear and less performance the engine will deliver.

Which will eventually result in the engine losing compression and failing. Since compression is one of the things that makes the engine run.

The piston rings do not seal well whenever this problem occurs. Something which will result in a lot of blowby air passing through. Reducing the compression levels significantly.

The solution to this problem will be an engine rebuild or purchasing a new short block to replace the existing one. The cylinder head can be reused.

Now let’s move to the next Hyundai Elantra 1.8 Nu engine problems.

2. Rod Bearing Failure

The second problem on our list of issues with the 1.8 Nu engine is rod bearing failure. This is a problem that affects both the Theta, Gamma, and Nu engines.

So, what is a rod bearing failure and why does it happen on these engines? Well, a rod bearing is a simple bearing that sits between the rod and the crankshaft.

These rod bearings resemble a semi-circle. So, for each rod, you have two rod bearings. In total for this engine, there are 8 rod bearings.

What can happen to these bearings is bearing wear because of the poor lubricating capacities of these engines.

The crankshaft manufacturing process was not one of the best and in many of these engines, there was debris that was not cleaned.

So, this debris ended up in the oil passageways. Which consequently prevents engine oil from flowing properly.

Resulting in poor lubrication of the bearings, rod wear, and rod knock to appear. Resulting in the need for an engine rebuild or a new short block to be installed.

However, this problem is more common on the Theta engine and the Nu is less affected. The following problem is more common to the 1.8 Nu engine.

3. Piston Slap/Ticking Sound

Many owners of the 1.8 Nu engine have complained about ticking noises coming from the engine. So, what is this ticking sound, and how serious it is?

Well, this is a similar type of engine damage as the rod knock. But this time instead of the bearings being affected, the one that is affected is the piston rings.

And this problem appears consequently to the oil consumption. The engine starts to consume serious amounts of oil and the piston rings instead of moving freely, become glued to the pistons since there are too many carbon deposits.

This situation then allows the pistons to wobble around in the cylinder. They become free and they slap the cylinder walls.

This situation is known as a piston slap and is represented as a ticking sound that comes from the engine.

So, if the engine ticks, you should definitely stay away from or at least measure the compression before you buy.

You need to make sure that this engine does not have a ton of blowby. If the engine suffers from a piston slap, you will most likely have to rebuild it or purchase a new short block. Which is something that is not cheap at all.

So, beware of these issues on the 1.8 Nu engine if you want to be safe.

Hyundai 1.8 Nu Engine Life Expectancy

The life expectancy of these engines might vary between 120,000 and 200,000 miles. It really depends on how lucky you are in most cases.

However, the average lifespan is somewhere between 120,000 and 150,000 miles. That’s why if it is a higher mileage engine, you should be prepared to replace the short block if it fails.

Hyundai 1.8 Nu Engine Reliability

The reliability of the 1.8 Nu engine is average. It is not one of the best engines in the world and also it is not the worst.

These engines do not last for a really long time though. So, you should be prepared for oil consumption, ticking noises, and engine failure whenever the engine collects a lot of miles.


We covered the specs and applications of the 1.8 Nu engine. This was a hugely popular engine option in the Hyundai Elantra.

Overall, this engine has the common Hyundai headaches. These Hyundai 1.8 Nu engine problems are oil consumption and piston slap. These situations are caused by engine wear, specifically on the piston rings that can wear substantially and cause the engine to lose compression. Which will result in the need for an engine rebuild.


What are the common problems of the 1.8 Nu engine?

Common problems with this engine include oil consumption, engine wear represented through rod bearing failures, and piston slap caused by poorly sealed rings. The engine will also lose compression and the end result will be a need for a new short block or an engine rebuild.

Is the 1.8 Nu engine reliable?

In general, these are the more reliable Hyundai engines that were released in recent years. Although they have a fair share of issues, they can go up to 200,000 miles in some cases. Which is not that bad.

When looking for such an engine, make sure that the engine is not ticking or knocking. If it does, you know that you have some serious issues to deal with and potentially replace the short block.

Also, we recommend that you do a compression test whenever you want to purchase a car with these engines. Or at least test it for blowby before buying. You can do this by removing the dipstick while the engine is working. If it blows a lot, the engine is probably worn out and needs to be replaced.

If you want to read more on Hyundai’s problems, you can check our articles on the 2.0 Nu engine and the 2.5 Smartstream engines.