Thinking about buying a Subaru with a 2.0L engine or already own one? You’re probably drawn to Subaru’s reputation for reliability and all-wheel-drive capability. But beneath that boxer rumble lurks some serious issues that have plagued different generations of their 2.0L engines. From excessive oil consumption to connecting rod failures, these problems can turn your dream car into a money pit.
I’ll walk you through everything you need to know about the common issues affecting Subaru’s 2.0L engines, their causes, and what you can do about them. By the end of this post, you’ll understand which model years to avoid and what warning signs to watch for if you already own one.
The Evolution of Subaru’s 2.0L Engines
Subaru has produced several generations of 2.0L boxer engines, each with its own set of strengths and weaknesses. Understanding the differences can help you make better purchasing and maintenance decisions.
EJ20 Series (1989-2019): The Foundation Years
The EJ20 is Subaru’s longest-running engine series, powering classics like the WRX, Legacy, and Impreza for three decades. These engines feature:
- Aluminum cylinder block with dry cast iron sleeves
- SOHC or DOHC configurations with four valves per cylinder
- Timing belt-driven camshafts
While generally more reliable than their 2.5L counterparts, EJ20 engines weren’t without issues. The fourth cylinder often ran hotter than the others due to cooling design limitations, leading to head gasket failures and valve spring problems. In fact, Subaru recalled about 140,000 vehicles in 2018 for valve spring issues that could lead to engine stalling.
FB20 Series (2011-2016): The Efficiency Disaster
The FB20 marked Subaru’s attempt to improve fuel efficiency while reducing emissions. Key design changes included:
- Smaller 84mm bore (compared to EJ’s 92mm)
- Longer 90mm stroke for better low-end torque
- Lighter components and looser tolerances to reduce friction
Unfortunately, these efficiency improvements came at a steep cost. The FB20 quickly became infamous for excessive oil consumption, leading to class action lawsuits and widespread owner frustration. The looser tolerances that helped improve fuel economy inadvertently allowed oil to bypass the piston rings at an alarming rate.
FA20 Series (2012-2021): The Performance Variant
The FA20 represents Subaru’s most sophisticated 2.0L design, featuring:
- Square 86mm x 86mm bore and stroke configuration
- Two main variants: FA20D (naturally aspirated) and FA20F/DIT (turbocharged)
- Direct injection technology (with dual injection in Toyota-partnered models)
The FA20D, used in the BRZ/86, benefited from Toyota’s expertise with a dual-injection system that minimized carbon buildup issues. The turbocharged FA20F used in WRX models, however, featured only direct injection, making it susceptible to intake valve carbon deposits and connecting rod failures under high loads.
Major 2.0 Subaru Engine Problems
Excessive Oil Consumption
The most notorious issue with Subaru’s 2.0L engines, particularly the FB20 (2011-2014), is abnormal oil consumption. Many owners report using a quart of oil every 1,000 miles or less, far above what should be expected from a modern engine.
Why It Happens:
- Poorly designed oil control rings become clogged with carbon deposits
- The horizontal boxer layout prevents gravity from helping oil drainage
- Thinner oil viscosity (0W-20) specified for better fuel economy
- Manufacturing tolerances that prioritize reduced friction over oil control
What makes this problem particularly insidious is that there’s often no visible blue smoke to alert owners. Many don’t realize there’s a problem until they check their oil and find it dangerously low, risking serious engine damage.
Subaru initially claimed that consumption of one quart per 1,200 miles was “normal,” but eventually acknowledged the problem was more serious. After a class action lawsuit, they began replacing short blocks in affected vehicles that failed oil consumption tests.
Carbon Buildup in Direct Injection Engines
FA20 engines with direct injection (particularly the FA20F in WRX models) suffer from carbon accumulation on intake valves. This issue typically becomes noticeable around 60,000-80,000 miles.
Why It Happens:
- Direct injection sprays fuel directly into the combustion chamber, bypassing the intake valves
- Without fuel washing over them, intake valves collect oil vapor and crankcase ventilation deposits
- These deposits harden over time, disrupting airflow and causing performance problems
Symptoms include rough idle, hesitation, reduced power, and poor fuel economy. The FA20D in the BRZ/86 largely avoids this issue thanks to Toyota’s dual-injection system that combines direct and port injection.
Cleaning requires expensive walnut shell blasting every 60,000-80,000 miles, costing $300-$800 each time.
Connecting Rod and Bearing Failures
The FA20F turbocharged engine has shown concerning susceptibility to connecting rod and bearing failures, even in some stock applications (though most commonly in modified vehicles).
Why It Happens:
- Asymmetrical connecting rod design creates stress concentration points
- Inadequate lubrication from oil consumption issues
- High cylinder pressures in turbocharged applications
- Manufacturing tolerances that may not provide adequate oil film thickness
When bearings fail, they generate metal debris that contaminates the entire lubrication system. This often requires complete engine replacement rather than simple bearing replacement, with costs ranging from $4,000-$8,000.
| Engine Model | Common Problems | Typical Repair Cost | Risk Level |
|---|---|---|---|
| EJ20 (1989-2019) | Head gasket failure, Valve springs | $2,000-$3,500 | Moderate |
| FB20 (2011-2014) | Excessive oil consumption, Rocker arms | $4,000-$6,000 | High |
| FB20 (2015+) | Improved oil consumption | $1,000-$2,000 | Low-Moderate |
| FA20D (BRZ/86) | Valve springs (early models) | $1,500-$2,500 | Low |
| FA20F (WRX) | Carbon buildup, Rod bearings | $4,000-$8,000 | Moderate-High |
Head Gasket Issues
While not as severe in 2.0L engines as in the notorious 2.5L variants, Subaru’s 2.0L engines (especially older EJ20 models) have experienced head gasket problems around the 100,000-mile mark.
Why It Happens:
- Early use of single-layer graphite-coated head gaskets that deteriorate over time
- The horizontal boxer layout puts additional stress on gasket sealing surfaces
- Inadequate cooling design for certain cylinders
Head gasket failures can be either external (coolant leaking outside the engine) or internal (coolant mixing with oil). Internal failures are particularly dangerous, creating a destructive “milkshake” that damages bearing surfaces and clogs oil passages.
Subaru eventually switched to multi-layer steel gaskets that proved more durable, but the reputation for head gasket issues continues to follow the brand.
Valvetrain Problems
Both FB and FA series engines have experienced valvetrain failures:
- FB20 engines have shown vulnerability to rocker roller failures where the rollers separate from their mounting points
- FA20 engines (especially early FA20D variants) suffered from valve spring fractures, leading to recalls
These failures typically result from inadequate lubrication, manufacturing defects, or design flaws. When they occur, they cause abnormal engine noise, misfiring, and potential valve damage.
The Financial Impact of 2.0 Subaru Engine Problems
Owning a Subaru with these engine issues can put a serious dent in your wallet. Here’s what you might expect to pay:
- Complete engine replacement: $4,000-$8,000
- Head gasket replacement: $2,000-$3,500
- Carbon cleaning service: $300-$800 (needed every 60-80k miles)
- Short block replacement for oil consumption: $4,000-$6,000
The boxer engine layout increases labor costs for nearly all repairs, as its horizontal design makes access difficult. Many owners report that repair costs often exceed the value of older vehicles, forcing them to either sell at a loss or scrap otherwise good cars.
Beyond direct repair costs, you’ll face:
- Increased depreciation
- Higher insurance premiums (for newer replacement engines)
- Lost time and transportation costs during repairs
Design Flaws Behind the Problems
Subaru’s 2.0L engine problems stem from several fundamental design choices:
The Boxer Layout’s Double-Edged Sword
The horizontal boxer layout provides a low center of gravity and smooth operation, but creates inherent challenges:
- Oil must fight gravity to return to the sump
- Any restriction in drainage passages can lead to oil starvation
- The design puts more stress on head gaskets than vertical engines
Efficiency Over Durability
In their pursuit of improved fuel economy, Subaru made compromises:
- Looser piston-to-cylinder clearances reduce friction but allow increased oil consumption
- Thinner oil viscosity specifications improve efficiency but may not provide adequate lubrication
- The FB series oil filter design allows oil to drain back when the engine is shut off, creating dry starts
Direct Injection Complications
While direct injection improves power and efficiency, Subaru’s implementation (particularly in the FA20F) lacks the dual-injection system that would prevent carbon buildup issues. This single-injection approach prioritized performance and cost savings over long-term reliability.
Recent Improvements and Current Reliability
Despite these historical problems, Subaru has made significant improvements to their 2.0L engines in recent years:
- The FB20 engines produced after 2015 have largely resolved oil consumption issues through revised piston rings
- Manufacturing quality control has improved across all engine families
- The FA20D remains relatively reliable thanks to its dual-injection system
In fact, Consumer Reports named Subaru the most reliable brand for 2025, suggesting that their newer engines have overcome many previous issues. However, reliability varies by engine family and application:
- Naturally aspirated engines tend to be more reliable than turbocharged variants
- Stock engines fare better than modified ones
- Post-2015 models show significantly improved durability
How to Protect Yourself If You Own a 2.0 Subaru
If you already own a Subaru with one of these engines, here are some critical steps to protect your investment:
Monitor Oil Levels Religiously
Check your oil level every 500 miles, especially in FB20 engines. Don’t rely on warning lights or visible smoke—by then, it may be too late. Keep a quart of the correct oil in your trunk at all times.
Use High-Quality Oil and Change It Frequently
Don’t skimp on oil quality or extend oil change intervals. Use only Subaru-approved oil weights and change every 3,000-5,000 miles, regardless of what the manual states for extended intervals.
Consider Preventive Carbon Cleaning
For direct-injection engines (FA20F), consider walnut shell blasting every 60,000 miles, even if you’re not experiencing symptoms yet. Prevention is much cheaper than fixing performance issues after they develop.
Watch for Early Warning Signs
Be alert for:
- Rough idle or hesitation (potential carbon buildup)
- Ticking sounds, especially when cold (possible valvetrain issues)
- Oil level dropping between changes (consumption problems)
- Sweet smell from the engine bay (potential head gasket leak)
What to Consider When Buying a Used Subaru with a 2.0L Engine
If you’re shopping for a used Subaru with a 2.0L engine, keep these points in mind:
Choose Model Years Carefully
- Avoid FB20 engines from 2011-2014 (oil consumption)
- Be cautious with FA20F engines with high mileage (carbon buildup)
- Look for post-2015 models when possible (improved reliability)
Demand Complete Service Records
Verify regular oil changes and look for any major repairs. If the vehicle has had engine work, find out exactly what was done and whether genuine Subaru parts were used.
Check for Recall Compliance
Ensure that all recalls have been performed, especially for valve spring issues in 2012-2014 models. You can check the NHTSA database using the VIN.
Perform These Specific Checks Before Purchase
- Check oil level and condition (look for metallic particles or milky appearance)
- Listen for unusual noises during cold start
- Look for blue smoke during acceleration (oil consumption)
- Test for smooth power delivery (carbon buildup causes hesitation)
- Inspect for oil leaks around the head gaskets
Consider an Extended Warranty
For models with known issues, an extended warranty can provide peace of mind, especially for turbocharged variants like the WRX. The cost may be worth it given the high repair expenses.
The Boxer Engine Legacy: Should You Still Consider a Subaru?
Despite these problems, Subaru’s boxer engines have many redeeming qualities:
- Exceptional balance and smooth operation
- Low center of gravity that enhances handling
- Distinctive sound that enthusiasts love
- Proven performance in rally and motorsport applications
The key is entering ownership with eyes wide open. Know what you’re getting into, budget for potential repairs, and stay vigilant with maintenance.
For many drivers, the unique character and all-weather capability of Subaru vehicles outweigh the potential reliability concerns, especially in newer models where many issues have been addressed.
Whether you choose to embrace the boxer rumble or look elsewhere, understanding these common 2.0 Subaru engine problems ensures you’ll make an informed decision based on facts rather than marketing.
