Subaru 2.5 Engine – How Reliable is the Engine?

Do you need to buy a new or used automobile, and are you looking for a 2.5-liter Subaru? If this is the situation and you want to learn more about the Subaru 2.5 engine, you have come to the correct place because there is a lot to discuss on this engine.

 

Before you ever consider buying a vehicle, you must conduct a thorough study of it. Before buying an automobile, you should become familiar with it. 

 

It takes more experience and knowledge than most people realize to select a car that is nice and will perform well within your budget. As a result, purchasing a car is more complicated than most people realize.

 

You should therefore familiarize yourself with Subaru and its engines. Because you’ll have the appropriate perspective and know what to anticipate from them, learning how these engines operate and their potential issues could save your life. 

 

You won’t be as taken aback as many other Subaru owners. Furthermore, there are several surprises in the Subaru 2.5 engine. You simply never know what you will receive in yours.

 

However, we’ll assist you in learning at least the fundamentals. We will first go through the fundamentals of the Subaru 2.5 engine. 

 

The advantages and disadvantages of the Subaru boxer engine design will next be covered, followed by information on the specifications for this engine. 

 

Later, we’ll talk about the issues with this engine, its dependability, and if you should buy it. So let’s get started.

 

A Boxer Subaru 2.5 Engine: What Type of Engine Is It?

So what exactly is the Subaru 2.5 engine? Subaru, a Japanese automaker, is the manufacturer of this engine. The EJ engine is another name for the device.

 

The EJ engine is a group of flat-four engines with displacement ratings ranging from 1.5L to 2.5L. However, because 2.5 is the most crucial engine for us at the moment, we will stick to it in this essay.

 

In all honesty, this engine family is what most people associate with Subaru. They don’t even consider abandoning this design because they have established a strong reputation around these engines.

 

As we noted, the EJ series was first released in 1988 and is still being produced today. The boxer engine design used in the EJ series. But what exactly does “boxer” mean?

 

The layout of the engine is referred to as a “boxer engine.” This indicates that the engines are not mounted vertically or at an angle like the V8 layout. But horizontal piston arrangement is what boxer engines use.

 

This indicates that the pistons are arranged horizontally and the crankshaft is in the dead center. When the engine is running, it appears as though two boxers are sparring. It is cool. 

 

The disadvantages of these engines are also important to discuss, and we will learn more about them in the chapters that follow, where we will also learn about the advantages and disadvantages of the boxer Subaru 2.5 engine architecture.

 

 

What are the Subaru Boxer Engine’s Advantages and Disadvantages?

Now, let’s take a quick look at the Subaru 2.5 engine. Let’s first go over this engine design’s advantages and disadvantages. Knowing this is incredibly helpful because everything is based on advantages and disadvantages.

 

Here, you may determine whether or not this engine is the best fit for your upcoming car. This is because flat engines are different from other types of engines and require a little bit more work to operate. 

 

However, we will go into more detail about that in the following two chapters when we clarify this.

 

What are the Advantages of the Boxer Engine?

Let’s first examine the advantages of the Subaru 2.5 engine. This engine’s distinctive design is one of its key advantages. 

 

The engine is different from other engine designs in that it is set up horizontally rather than vertically. This engine is ideal for you if you’re one of those people who wants something unique.

 

The vehicle’s general stability is another factor. Because of how low the boxer engine is positioned in the engine compartment, your car will have a low center of gravity. 

 

A lower center of gravity increases driving stability. Compared to certain cars with V8 engines or inline engine designs, the car will handle far better.

 

The balance of the car will also be enhanced by the engine’s low position. You’ll note that there are hardly any vibrations inside a Subaru if any at all. All of this is made possible by the excellent engine design, which produces no vibrations at all.

 

The safety feature of the boxer engine is another advantage. The engine is positioned low, which will aid to protect you in the event of an accident. And that concludes the Subaru 2.5 engine’s advantages. Let’s now examine the downsides of this engine.

 

What are the Disadvantages of the Boxer Engine?

Let’s move on to the downsides of the Subaru 2.5 engine. In addition, a handful of these drawbacks have the potential to cause you to rethink your decision.

 

The upkeep of the boxer engine is its primary drawback. The cost and maintenance for this engine are both fairly high. Why is this the case, then? Let’s expand.

 

This engine is arranged horizontally, taking up the entire engine bay from one side to the other. Simply put, there aren’t many places to do repairs. This makes it challenging to replace even basic components like spark plugs. 

 

The entire engine must be removed for some more complicated work, which is rather expensive to carry out.

 

In addition, these engines are a little more complicated than a typical inline engine and need technicians with greater expertise to work on them. 

 

This means that for any work to be done properly, you will frequently need to drive your Subaru to the dealership. Additionally, there are not many independent Subaru dealerships in the country.

 

Additionally, there are certain inherent issues with this engine architecture. And these issues persist with every Subaru 2.5 engine you purchase. 

 

But first, let’s talk about the EJ engine’s specifications. Since this post is solely about the 2.5L, we shall concentrate on that engine.

 

 

What are the Specifications of the Subaru 2.5 Engine?

Our discussion of the Subaru 2.5 engine will center on the EJ25 engine and its variants. EJ designates that the engine is a member of the EJ family, and 25 denotes that it has a 2.5L displacement.

 

It is important to note that this moniker refers to several engines. The EJ25D is the oldest of the group. From 1994 to 1999, this engine was manufactured and shipped with the Impreza, Legacy, and Forester models. 

 

About 158 horsepower and 220 lb-ft of torque were produced by the engine, which was naturally aspirated.

 

Then, over the years, there were various modifications. In particular, the EJ251 engine, which used a single overhead camshaft design, was a significant upgrade over the basic engine. It generated a little more power, precisely 165 horsepower.

 

The next engine was the EJ255, the most potent one Subaru had to offer. The power output of this high-performance engine ranges from 207 to 261 horsepower. High-performance apps had it in them.

 

The FB family of engines has taken the place of the EJ in the current versions. Specifically, the FB25B and FB25D. All models from 2020 and later use the most recent D model. 

 

These normally aspirated engines have 170 horsepower for the B model and 182 horsepower for the D variant.

 

So, if you want to get a new Subaru, it will probably come with the FB25D. But what are the uses of the Subaru 2.5 engine? In the chapter after, let’s get into more detail.

 

What are the Applications for the Subaru 2.5 Engine?

Let’s find out more about how the Subaru 2.5 engine is used now. Which Subaru models can you initially locate these engines in?

 

Fortunately for you, several Subaru models employ this engine, so you shouldn’t be upset if your favorite Subaru doesn’t have one.

 

The fact that this engine is extremely adaptable and may be employed in various applications is crucial. However, not in every Subaru on the road.

 

For instance, it’s unfortunate that the Impreza does not use the most contemporary F25B. But sometimes things do work out like way. Only Legacy, Outback, Forester, and Crosstrek use the newest 2.5 engine.

 

Contrarily, the EJ is present in the aforementioned models as well as the Impreza, Impreza WRX, and the Subaru Baja, which was a discontinued model.

 

The fact that this engine is also in the Saab 9-2x is peculiar. was the sole non-Subaru vehicle to use this engine. All in all, that is all there is to know about the Subaru 2.5 engine’s applications.

 

The EJ is used before 2020, while the FB is utilized following 2020. The FB engine is the most recent one produced by Subaru and is also a lot more dependable than the EJ engines. 

 

But for now, we’re in uncharted waters. These are the issues with the Subaru 2.5 engine.

 

We’re not finished with this Subaru engine, so don’t worry. In the chapters that follow, we’ll discuss just that and concentrate on the primary issues with the Subaru 2.5 engine.

 

What are the Common Problems with the Subaru 2.5 Engine?

Now that we’ve gotten to the crucial part of the Subaru 2.5 engine, let’s talk about the issues this engine has. 

 

Understanding the issues with this engine will be of great assistance to you as you choose between a Subaru and perhaps another type of vehicle.

 

And regrettably, the Boxer engine has drawbacks that merit discussing. These issues range in severity, with some being significant and others being minor. 

 

However, we will discuss them anyhow because we want you to have the best and purchase a vehicle that you will adore and value. So, keep reading if you want to discover more.

 

1. Issues with the Head Gasket 

The head gasket issue is the main issue with the EJ Subaru 2.5 engine. They simply enjoy breaking these engines.

 

Poor gasket materials are to blame for more of these failures. However, some of these are also a result of engine design. The gaskets typically lie flat or at an angle. 

 

However, the gaskets in boxer engines are vertical. Therefore, gravitation has no advantages for them.

 

Meaning that because they are put in this manner, it is far more likely that they will leak. Since the gaskets on many of these engines are small, coolant seeps from the sides of the engine and burn up as the gaskets deteriorate.

 

This issue frequently renders this engine very unreliable because it is susceptible to significant damage, especially if the engine has been operating this way for some time without being checked by a professional.

 

Running an engine with this kind of issue ensures that subsequent costly repairs will be necessary. As a result, you must be aware of this issue and ensure that the Subaru 2.5 engine you choose is reliable. It is preferable to be safe than regrettable afterward.

 

Oil and coolant may mix as a result of a burst head gasket’s potential consequences. Furthermore, if you drive your automobile in this manner, the engine’s bearings may burn up, therefore this combination is bad. 

 

As a result, the entire engine will need to be rebuilt or replaced. Be on the lookout for this issue. Let’s now discuss the Subaru 2.5 engine’s additional issues.

 

 

2. Excess Consumption of Oil 

Oil consumption, which this engine experiences, is the Subaru 2.5 engine’s second largest issue. Yes, it is correct. Other engines don’t consume as much oil as Subaru engines.

 

The EJ engine has a particular issue with its oil rings, which frequently fail after a significant amount of kilometers and start to let some oil inside the combustion chamber.

 

The oil begins to burn as soon as it enters the combustion chamber. You’ll notice that the oil light will turn on and the car will start to lose oil pressure when the oil is burning.

 

You should always check the oil level and you shouldn’t neglect this. Most likely, the oil has to be topped off because it is running low. 

 

Carrying a quart of oil in the trunk will help you top off the oil anytime it gets low if your automobile tends to consume more oil than it should.

 

Are all of Subarus affected by this issue? In general, engines that have traveled around 100,000 miles, are more accurate. 

 

At this time, the engines start to exhibit their drawbacks, but on Subarus, this occurs more frequently, leading some people to wonder if Subarus are a decent second-hand alternative. because compared to other cars, they are far more prone to difficulties.

 

They are good, but the maintenance this Subaru 2.5 engine had over its lifetime is of utmost importance. You shouldn’t be too concerned if this engine was maintained. Let’s turn our attention to the next issue, though.

 

3. The Subaru 2.5 Engine Oil Starvation 

Another issue this engine has is oil hunger. This is a problem with the engine’s design, specifically. These engines need better lubrication due to the manner they were built, and it is frequently challenging to lubricate them adequately.

 

Especially when oil consumption is a problem for the engine. And the difficulties with oil starvation become considerably worse if you leave it like this for a long period on low oil.

 

The rod bearings will sustain the most damage, and the rods will begin to clatter. Simply put, rod bearings with little or no oil do not want to operate. Engine damage is likely if they do.

 

indicating that eventually the engine will start to deteriorate more quickly and you may need to thrash it. We’ll require a new engine. or reworking the current engine.

 

Because of this, you must be aware of the issue and take precautions to ensure that your Subaru 2.5 engine doesn’t run out of oil.

 

What Is the Reliability Rating for the Subaru 2.5 Engine? 

What is the Subaru 2.5 engine’s reliability rating then? Is this engine trustworthy or not? The solution, however, depends.

 

The issue with Subaru engines is that their overall architecture makes them more vulnerable to issues. This could be a drawback. However, they also have a ton of benefits that will ensure you become a Subaru lover and never consider anything else.

 

About 3.5 stars out of 5 are assigned to this engine’s overall dependability. I believe that this is a respectable grade, and most people will concur.

 

These engines are among the best available when they are in comparatively excellent condition. however, when their owners do not show them as much love. They’ll expose their flaws and make you regret making the purchase.

 

So, should you purchase a Subaru 2.5 engine? Are you sure? In the chapter that follows, we’ll go into more detail about this subject and try to give you an honest response that will make your purchasing decision simpler and easier to make.

 

Is It Worth Investing In the Subaru 2.5 Engine?

Should you, then, purchase the Subaru 2.5 engine? Yes, you ought to purchase it. However, you must also be conscious of the situation you are entering. 

 

Knowing the drawbacks of the engine will be very beneficial to you since you will be ready for any potential issues, such as the head gasket issue and the oil burning issue that is known to occur.

 

Each of these problems varies in severity and will cost money to resolve. Simply said, you cannot hope to solve them with a few pennies.

 

Sorting them out will take a lot of effort. This is due to the engine’s low position and proximity to the engine bay walls. Since there is less room to work on the engine, it will take more time and money to complete the majority of the regular tasks.

 

Additionally, there are not many independent Subaru stores in the United States. Therefore, the majority of the problems you encounter must be handled by the dealership. 

 

Additionally, dealerships are well-known for being pricey, so having your vehicle fixed there will incur a significant expense. If you want to keep your costs to a minimum, you must become your mechanic.

 

Additionally, you want to look for an illustration with modest mileage. Avoid buying an automobile with a greater mileage because most of them aren’t that great. or if the vehicle has a higher mileage. Make certain it was well-cared-for and cherished.

 

 

A Summary of All You Need to Know About the Subaru 2.5 Engine

The 2.457L Subaru 2.5 engine is a 16-valve flat-four boxer that is both naturally aspirated and turbocharged.

 

Depending on the year, manufacture, and model it is used in, the engine’s horsepower and torque range from 155 to 172.6 and 140 to 170, respectively.

 

From 1994 to 1996, the Subaru 2.5 engine was available in the GT, LSi, and Legacy Outback trim levels of the Legacy.

 

The Subaru 2.5 engine’s flat-four configuration allows for direct communication between the engine and transmission, which enhances handling and fuel economy.

 

The engine’s lower center of gravity improves speed and handling, and in an accident, it drops below the passenger compartment, minimizing injuries.

 

The EJ25D was succeeded by the EJ254 and EJ257, twin overhead cams variants that are only occasionally used because the flat-four’s intricate construction makes changing plugs challenging.

 

Beginning with the EJ251, many more Subarus were equipped with a single overhead cam design.

 

A 2.5 engine is available in the Legacy, Outback, Baja, Forester, and Impreza models of Subaru.

 

The head gasket and crankshaft oil/seal oil leaks, as well as a banging sound that originates from the fourth cylinder, are problems with Subaru 2.5 engines.

 

Every Subaru 2.5 engine is an interference engine, which means that if the timing belt malfunctions, it could result in significant harm.

 

 

The Conclusion 

We’ve spoken about the Subaru 2.5 engine quite a bit in this article. First, we gained knowledge of what a boxer engine is and its advantages and disadvantages. There are a handful of them, and you should pay attention to them.

 

The 2.5 engine specifications and the uses for this engine were then discussed. Furthermore, this engine is included in the majority of Subaru vehicles.

 

Then, as we recall, there are a few issues with this engine, which we have learned about. Specifically, problems with the head gasket, oil consumption, and oil starvation. Finally, we discovered whether or not getting one for yourself is a wise idea.

 

 

RECOMMENDED TOOLS

Here are our recommended tools that have been tried and tested by our experts. They are of great quality and with a 5-star rating on Amazon.

 

• Auto Jump Cables
• Read – Reset OBD Diagnostics
• Professional OBD Diagnostics
• Professional Car Jacks
• Socket Wrench Ratchets
• Mechanics Tool Set
• Rechargeable LED Work Lights
• Impact Wrench Kit
• Digital Multimeter
• Battery Charger
  

Motor Pinnacle is a participant in the Amazon Associates Program. We will earn a small commission when you purchase any product using our affiliate links. This is at NO added cost to you. By utilizing our affiliate links, you are assisting us to keep this blog running; we are so grateful for that.