Subaru is a reputable Japanese car company, building consumers’ trust through its consistent quality cars.
However, in recent years, customers have often complained about the decrease in engine performance. Therefore, many Subaru seekers always consider which Subaru engines to avoid when purchasing.
We will point out major issues that appear in subpar engines.
Besides, we will provide a few more information about the Subaru boxer engine issues. Scrolling to the end, you may find some helpful things in the FAQ section.
Are Subaru Engines Reliable?
Due to a few low-quality items in the ocean, customers are starting to doubt if the rest of Subaru’s products are worth buying.
It is not random that Subaru has a firm position in the tough car market.
Up to now, Subaru is considered an automobile company with stable and reliable quality, reflected in its comfortable interior, flexible access, and fuel economy.
In particular, Subaru’s boxer engines continuously pass rigorous reliability tests. Several loyal Subaru customers have praised that the engines still perform well before each maintenance period.
Based on data collected from a Customer Report in 2021, Subaru is proud to be in the top 25% of most credible automobile brands.
It is a fact that firms can rarely satisfy customers absolutely with all their items. Each brand has excellent products and vice versa.
Subaru is not an exception. So, apart from the list below, Subaru is still a car brand you can consider.
Which Subaru Engines To Avoid?
What Subaru engines to avoid? 3 engines, namely, Subaru 2.5-L Turbo 4 Cylinder, SUBARU EJ25, Subaru EJ205/EJ207/EJ20G Engine, are more likely to malfunction than others, notably the oil-related issues.
Let’s check each model.
1. Subaru 2.5-L Turbo 4 Cylinder
This engine was engineered in the 2009-14 Subaru Impreza WRX and WRX STI models.
According to common complaints, drivers noticed that the contact points between the piston ring and the ground had weakened significantly in this engine system.
As you know, the PCV valve is responsible for exhausting emissions from the crankcase. In this cylinder, however, the system allows crankcase oil vapor to enter the combustion chamber.
This condition not only mitigates the fuel mixture but also overloads the pistons. The engine is highly on the verge of damage.
The improper performance causes internal components to overheat or stick. The vehicle may suddenly lose power or stop on the way.
In fact, many drivers of these mentioned car models have experienced this unpleasant situation. Besides, crankshafts and bearings express oil issues, leading to heated engines.
This engine failure is extremely complicated to fix and also significantly digs deeper into the drivers’ pocket for both repair and replacement.
2. SUBARU EJ25
The Subaru EJ25 is commonly installed in Subaru Forester and Legacy lines, and it has the most errors. The engine includes two forms: a naturally aspirated 2.5-liter boxer engine and a twin camshaft.
Major issues are still oil-related, including oil combusting, oil shortage, and head gasket failure.
Typically, these errors appear due to external agents after long usage. At Subaru, the inconsiderate engine engineering is the reason behind it.
As a result, the quality, performance, or endurance is not highly rated.
3. Subaru EJ205/EJ207/EJ20G Engine
We continue with the engine stuck with oil problems from Subaru. Unlike the two names above, engine oil leakage is a common error in EJ205/EJ207/EJ20G Engine, resulting from the clogged rings.
Subaru tried to comfort the users by its explanation about more premium oil and fuel quality. However, most of the customers consider it an excuse.
Besides, the air-conditioned intercooler seems hit-and-miss since it can not cool down the engine core during operation, especially in high-load performance.
If the engine, unfortunately, experiences overheating, it will remain until fully damaged.
Subaru Engine Problems
You can easily recognize that the listed Subaru malfunctioning engines have oil problems. Join us to know more details about these issues.
Oil Leakage
The root cause of oil leakage belongs to the head gasket issues. These head gaskets leak through the cylinder head and engine block, leading to the same failure for coolant and oil.
This error occurs depending on the structure, especially the material of the head gaskets.
Graphite-coated head gaskets have been found in vehicles with damaged engines. This shell’s adhesion is considered unstable, gradually fading after about 100,000 miles.
Discarding this adhesive means that the head gasket is more vulnerable.
Responding to the customers’ disappointment, Subaru has replaced the graphite head gasket with an uncoated multi-layer head gasket.
Oil leakage occurs most often in the 2.5-L engine EJ25D- a common built-in component of the Subaru Forester, Legacy, and Impreza line.
Oil and Coolant in the Chamber
Cylinders with bad designs can enable considerable amounts of oil or antifreeze ( so-called coolant) to penetrate the combustion chamber and burn.
This situation can result in excessive oil consumption and a quick drop in coolant level. If a shortage of coolant is not detected in time, the engine can overheat, damage, or, more dangerously, catch fire.
This error is usually signaled by smoke. Black smoke means that engine oil is burning. Meanwhile, white smoke is a sign of burning coolant or any cool component in the engine.
Subaru Boxer Engine Problems
Subaru and Porsche are two well-known car manufacturers using boxer engines.
In particular, almost all of Subaru’s cars install this component, which is formed and innovated according to the company’s technologies.
A Boxer engine (also known as a flat internal combustion engine) is an automobile engine in which pistons and cylinders are arranged horizontally and symmetrically.
The pistons are placed on the same plane, so their movements look like boxers. That’s how the engine has been named after.
Through the symmetrical horizontal structure, when the Boxer engine is operating, the two piston sequences will generate opposing forces, thereby canceling each other.
This operation offers a comfortable drive, a higher performance as well as durable longevity.
The problem lies in the engine’s motion which is not smooth and harmonious.
Besides, this engine is built with 2 heads. It requires two rows of cylinders, so the production cost will be much more expensive.
Subaru designed the Boxer Engine with a wide range. The structure expands horizontally but flattens in height (like a wide rectangular block).
This design triggers many difficulties in engine layout. The manufacturer had to build its own chassis with more complex calculations to install the Boxer engine.
Other drawbacks to mention are short rods and small bases, which have obstacles in withstanding heavy loads.
The rod pistons are also more likely to break down. In addition, the installation or repair of the engine is not easy and economical.
Why Do Subaru Engines Fail?
The built-in faulty fuel pump of the 2019-2018 models shows performance problems.
The fuel pump is cracked, hindering the process of power generation for the engine, so it may become sluggish, vibrate strongly, or make a loud noise.
You can expect the engine to suddenly stop while the car is running, easily causing accidents on the highway.
Many drivers wonder why their check engine light becomes glowing.
That could be a sign of failure, and it’s time to replace the fuel pump. Ascent SUV, Impreza, or Legacy are still models with this condition.
That’s not the end of the story. Over 200,000 Subaru (Impreza and Subaru Crosstrek) models have their engines damaged due to the vehicle’s computer system.
The computer part was initially programmed with no finesse and precision.
Specifically, it does not stop supplying power to the ignition coil even when the motor is turned off.
Besides unnecessarily boiling the engine, it also induces electrical issues, such as fuse explosion, short circuit, or sudden engine power loss.
PCV valves are also the culprit of Subaru’s failed engines, namely cracks or separations. Split pieces of the PCV valve or oil can pass through that omission to enter the combustion chamber.
Not only causing excessive oil consumption, but the whole engine is also quickly degraded over time.
Operating with an PCV valve error, the car’s engine is difficult to activate, vibrates, or shuts down. A jammed PCV valve can cause the Check Engine light to come on.
FAQs
Which Year Does Subaru Have Engine Problems?
2017-2019 is the period when Subaru models have the most problems, namely the Subaru Forester, Impreza, and Legacy.
The 2017 Subaru Forester is not recommended because of its weak engine coupled with electrical issues.
The battery system expresses poor life, which flickers when the car has not even reached 30,000 miles yet. The radio and navigation systems are also unreliable.
The manufacturing’s bugs throughout 2017-2019 does not exclude the Imprezas line.
The problems are not only related to electrical issues and computer programs but also engine components like cracked valve PCV or cracked oil pump.
Owners of these models often notice that the Check Engine signal lights up continuously for uncertain reasons.
Which Subaru Engine Has Head Gasket Problems?
The 2.5-L SOHC and EJ engines were disappointing because of a serious head gasket error.
The number of Subaru vehicles with malfunctioning head gaskets recorded at auto repair shops is increasing, exactly in the Forrester, Impreza, and Legacy lines.
This error leads to oil and coolant leakage, overheated engines, and excessive oil consumption. Dealing with this complaint, Subaru decided to apply for warranty extensions at 100,000 miles.
What Are The Disadvantages Of A Subaru Boxer Engine?
The two biggest problems with Subaru boxer engine lie in the boxer engine size and repair/replacement.
The boxer engine is massive and takes a lot of space, especially in width. Therefore, producing a specific framework fitting this component is considered expensive.
Repairmen also need to spend more time and effort tackling any problem of a boxer engine.
The boxer engine is structured as a flat-four form, of which engine heads, camshafts, head gaskets, and even timing belts are twice that of a straight-four engine.
The space to reach the engine head is relatively tight.
Whenever you want to change the head gasket or others, the engine must be taken out, which is complicated and time-consuming and costs you significantly.
What Are The Advantages Of A Subaru Boxer Engine?
We can not deny the benefits that the boxer engine contributes to your drive. Compared to conventional engines such as V-engine or I-engine, the boxer engine has the best balance.
The pistons are symmetrically designed to reduce vibration, helping the engine operate more smoothly.
The boxer engine is placed horizontally with a flat design and low center of gravity, creating good and neat handling and cornering regardless of road conditions.
In addition, thanks to the CVT automatic transmission, the transmission is also more efficient.
Smooth acceleration is no longer out of your reach. Indeed, the boxer engine is extremely suitable for the driving enthusiast.
How Many Miles Will A Subaru Boxer Engine Last?
Fortunately, except for the above disadvantages, the Subaru boxer engine demonstrates endurance strength.
The boxer engine can endure an average of 250,000 miles, and the most reliable Subaru engine can serve up to 300,000 miles.
This number can increase if other components (head gaskets) steadily operate.
Unlike other parts (small, easy to disassemble, etc.), the boxer engine is difficult to maintain on a regular basis. In return, it’s also less likely to get corrupted.
Conclusion
We hope to have satisfied you with our detailed answer to concerns which Subaru engines to avoid.
In sum, Subaru cannot meet the customer satisfaction in the Impreza, Legacy, and Forrester models during 2017-2019.
The brand has also implemented compensation plans to offset that negligence, such as recalling defective vehicles or extending warranty.
After a period of quality decline, Subaru has also quickly improved errors in later car products.
Fortunately, the 2020 and later models have been well evaluated and trusted again. All in all, Subaru is still a worth-considering option when buying a car.