Subaru began manufacturing the WRX in 1992 and continues to do so today. In honor of their rally heritage, the name “WRX” stands for “World Rally eXperimental.” Subaru WRX and STI models feature rally-inspired technology such as all-wheel drive, stiff suspension, and turbocharged four-cylinder engines. This contributes to the WRX’s popularity in the worlds of racing and tuning.
Without a doubt, the WRX is a fun, sporty car. However, does this imply a reduction in reliability? This guide discusses the reliability of the Subaru WRX and STI, as well as common engine problems.
*It is also referred to as the Impreza WRX. Subaru, on the other hand, dropped the Impreza moniker for model years 2015 and beyond. 6587
Subuaru WRX Over the Years
Prior to delving into the meat of this article, there are a few critical points to make. WRX models have been available for nearly three decades. It has thus far spanned four chassis generations. Additionally, over the years, a variety of different engines have been used to power WRX & STI models. The following is a partial list of those engines:
- EJ20G (1992-1998)
- EJ20K (1996-1998)
- EJ205 (1999-2006)
- EJ255 (2006-2015)
- FA20F (2015-present)
- EJ257 (2004-present) STI models only
We’ll discuss reliability in general, but our primary focus will be on the WRX engines. Over time, we’ll compile a guide for each engine (with links above). This article will primarily focus on a few issues that are common to a large number of WRXs. Certain years and models will have a higher or lower level of reliability than others.
Impreza WRX Tuning, Mods
A portion of what we’re discussing in this article relates to the tuning capability of the WRX and STI engines. With their rally-inspired styling and turbocharged engines, it’s simple to squeeze more performance from these Subarus.
Modifications and tuning are quite common. Numerous WRXs are capable of gaining 50-100+ horsepower with a tune and some simple bolt-on modifications. With the addition of a turbocharger, the WRX/STI engines can produce even more power.
Generally, this is accompanied by owners who drive and push their cars harder. Often, we discover that these same owners are also quite adept at maintaining their properties. As such, there may be some balancing effect. Regardless of the case, increasing the power of a stock engine increases the likelihood of something going wrong.
Effects on Reliability
This is not intended as a dig at Subaru owners, as this can occur with any easily tuned engine. It’s a common occurrence in the BMW world. Without a thorough understanding of engines and tuning, less experienced owners may install a substandard tune and cheap bolt-ons.
They attempt to squeeze every ounce of power from the engine rather than being conservative and safe. This can undoubtedly have a detrimental effect on the Subaru WRX / STI’s reliability.
With a conservative tune, the proper supporting mods, routine maintenance, and data logging, this setup can be extremely safe. In these instances, the impact on reliability or longevity should be minimal. The point is to be cautious of who you purchase a WRX from and how they may have previously treated and tuned the vehicle.
Subaru WRX Common Engine Problems
With that out of the way, let’s get into the meat of this article. The following are some of the most frequently encountered issues with the Subaru WRX and WRX STI:
- Engine internals
- Turbo failure
- Oil leaks
- Misfires
These are the most frequently encountered issues for a reason. This does not necessarily imply that the issues are widespread and affect a sizable proportion of WRXs.
Rather than that, when issues do arise, these are some of the more common areas. Additionally, some of these failures may be more prevalent on specific model years and engines. They do, however, affect nearly all Subaru WRX engines to varying degrees.
We’ll examine each of the aforementioned WRX/STI engine issues in detail and conclude with some general thoughts on reliability.
1) WRX & STI Internal Engine Failures
Internal combustion engines contain numerous moving parts that can fail. These are serious issues that are likely to be costly at best and may result in engine failure entirely. Unfortunately, the WRX and STI engines’ reputation for internal strength has not been stellar.
It is rarely a problem on completely stock engines, however. When tuned and modded, WRX internal engine problems are more likely to occur. Several well-known weak points include the following:
- Rods
- Rod bearings
- Pistons
- Piston rings
These issues appear to be most prevalent on EJ255, EJ257, and FA20 engines manufactured after 2004. There have even been a few lawsuits filed against these engines due to internal engine issues. However, these issues may occur with all Subaru WRX and STI engines.
If you intend to tune and modify the WRX, make certain you maintain a proper, conservative tune. Internal engine damage is frequently the result of pre-detonation. You want to ensure that your engine is not running lean, that significant timing pulls are not occurring, and so forth.
Subaru Internals Upgrades & Replacement
Upgrading the pistons, rods, and/or bearings is one way to mitigate risks. This is a time-consuming process that is usually not worth the cost unless you intend to make a lot of power (350-400+whp).
The stock internals, on the other hand, can and do let go at stock power and even with modest tuning. In these instances, repair costs can quickly exceed $2,000+. Additionally, internal engine failures are not uncommon.
2) Subaru WRX Turbo Problems
Internal problems such as those listed above are slightly more prevalent on newer WRX engines. Turbo issues, on the other hand, are more likely to affect older models. Turbo technology has advanced significantly over the last 10-15 years. They were not quite as reliable in the past, and turbo lifespans were typically shorter. Having said that, many older Subaru WRXs may already have had their turbos replaced.
Otherwise, turbo issues become more prevalent when tuning and customizing Subaru WRX and WRX STI models. Typically, the increase in power comes from running more boost. This can place a significant amount of additional strain on the stock turbo. Proper supporting mods can go a long way toward extending the turbo’s life.
Finally, turbochargers are mechanical components that are prone to wear and tear. At maximum boost, they can reach speeds of up to or exceeding 150,000 RPM. Natural wear failures are not uncommon above 120,000 miles. However, modern turbos can occasionally last nearly twice as long.
3) Subaru Oil Leaks
Oil leaks are a very common occurrence. Engines contain a variety of gaskets and other components that can leak oil. At some point during their lives, the majority of Subaru WRX & STI models will develop an oil leak. Several common areas where leaks occur include the following:
- Valve cover gaskets
- Oil pan gasket
- Main seals
None of these are particularly common problems with the Subaru WRX engines. Gaskets, on the other hand, are subject to wear and tear over time. It’s probably not fair to refer to oil leaks as a true problem, given that aging engines frequently develop leaks.
Nonetheless, if you’re considering purchasing an older WRX or maintaining a newer one for the long haul, you may encounter a minor oil leak or two.
4) Subaru WRX Misfire Issues
Another somewhat ambiguous issue here. WRX misfires are a rarity. Rather than that, misfires indicate that the engine has another underlying problem. It’s common on turbocharged engines due to their proclivity for rapidly burning through spark plugs and ignition coils.
That is simply routine maintenance, and we do not believe it is accurate to label them as problems. Consider the following parts if your Subaru WRX/STI is experiencing misfires:
- Spark plugs
- Ignition coils
- Fuel injectors
- Carbon build-up
Without a doubt, spark plugs and ignition coils are two of the most common causes of WRX misfires. Misfires can also be caused by leaking or faulty injectors. Finally, misfires can occur in newer direct injection (DI) Subaru engines as a result of excessive carbon buildup.
Carbon build-up is typically not an issue on the WRX until well over 100,000 miles. It is routine maintenance on DI engines because no fuel flows over the intake valves to clean them.
Subaru WRX Reliability
Is the Subaru WRX and WRX STI a trustworthy vehicle? True and false. These engines frequently earn lower reliability ratings than lower performance Subaru engines. Nevertheless, it makes sense. In general, performance vehicles and turbocharged engines are a little more demanding.
This is especially true when there is considerable scope for tuning and aftermarket development. Numerous Subaru WRX models are modified at some point during their lives. Even when done correctly, it can still increase the overall stress placed on the engines.
The point is that the WRX is not as reliable as many non-performance vehicles on the road. However, it is fairly reliable when considering turbo engines and high-performance vehicles. Spark plugs and ignition coils deteriorate more rapidly.
Suspension deteriorates more rapidly. Turbochargers add a slew of additional components and potential trouble spots. This is a natural consequence of owning a rally/race-inspired car such as the Subaru WRX or WRX STI.
If you intend to tune and modify the vehicle, stay conservative or upgrade the internals. Utilize high-quality oils, keep up with routine maintenance, and address issues as they arise. All of this adds up to a fairly reliable car and engine in the Subaru WRX.
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