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Subaru Forester Reliability: Engine Issues & Best Years

JH
John H
Senior Cars Expert
8 min read

Subaru Forester Reliability: Engine Issues & Best Years

The Subaru Forester has long been a favorite among compact SUV shoppers who value all-wheel drive, practicality, and rugged design. Known for its go-anywhere capability and impressive safety ratings, the Forester has built a loyal following over its decades in production. However, one of the most common concerns potential buyers have is reliability — particularly engine issues that have affected certain model years. In this comprehensive guide, we’ll dive into the Subaru Forester's reliability record, explore common engine problems across different generations, and highlight the best and worst model years so you can make an informed decision.

Overview of Subaru Forester Generations

Since its debut in 1997, the Subaru Forester has gone through five generations, each bringing improvements in technology, comfort, and performance. Understanding these generations helps identify which models are more reliable and which to avoid.

Subaru Forester Reliability Ratings

According to J.D. Power, the Subaru Forester has earned above-average reliability scores in recent years. The 2023 model received a 4 out of 5 predicted reliability rating, while Consumer Reports has consistently ranked the Forester among the most dependable compact SUVs.

However, historical data reveals that not all model years are created equal. Some years — especially from the second and third generations — have higher-than-average repair frequencies and costly engine issues.

Common Subaru Forester Engine Problems

While Subaru's boxer (flat-four) engines are praised for their balance and low center of gravity, certain models have been plagued by recurring engine issues. Here’s a breakdown of the most frequently reported problems.

1. Head Gasket Failure (2006–2009 Models)

One of the most notorious issues in Subaru history is the head gasket failure, affecting various models including the Forester. The 2006–2009 Forester models — particularly those with the 2.5L naturally aspirated engine — are most susceptible.

Symptoms:

Head gasket failure is expensive to repair, often costing $1,500–$2,500. While Subaru extended warranties for some affected vehicles, many owners had to pay out of pocket if their car was outside the coverage period.

2. Timing Belt and Water Pump Issues (2003–2008 Models)

The second-generation Forester used an interference engine, meaning that if the timing belt breaks, internal engine damage is likely. The timing belt is recommended for replacement every 105,000 miles, but many owners report failures before that milestone.

The water pump is also driven by the timing belt, so it’s recommended to replace both components at the same time. Neglecting this maintenance can lead to costly engine repairs.

3. Turbocharged Engine Problems (2004–2013 XT Models)

The turbocharged 2.5L engine (EJ255) found in the Forester XT models from 2004 to 2013 has a mixed reputation. While it delivers strong performance, it’s prone to several issues:

4. Carbon Buildup on Valves (2012–2018 Models)

Starting with the 2012 model year, Subaru introduced direct fuel injection (DFI) in some engines. While this improves fuel efficiency and performance, it also contributes to carbon buildup on intake valves — a known issue in many DFI engines.

Without detergent-rich fuel or regular maintenance, carbon deposits can restrict airflow, leading to:

Periodic walnut blasting or intake cleaning is recommended to maintain engine performance.

5. Oil Leaks (Various Years)

Subaru boxer engines are known for oil leaks, especially as they age. Common sources include:

While not catastrophic, persistent oil leaks can lead to engine damage if ignored. Valve cover gasket replacements are relatively affordable ($200–$400), making them easy to address early.

Transmission and Drivetrain Issues

While engine problems are the most discussed, some Forester models have also experienced transmission-related issues.

Automatic Transmission Slipping (2006–2008 Models)

Some owners of the 2006–2008 Forester automatic models report transmission slipping, harsh shifting, or delayed engagement. These issues are often linked to worn solenoids or degraded transmission fluid.

Regular transmission fluid changes (every 30,000–60,000 miles) can significantly extend transmission life. Some third-party fluid additives have shown success in reducing symptoms, but severe cases may require a rebuild or replacement.

CVT Transmission Reliability (2010–Present)

Starting in 2010, Subaru phased in continuously variable transmissions (CVT) across the Forester lineup. Early CVT models had reliability concerns, including:

However, Subaru improved the CVT design in later models. The 2014 and newer Foresters with CVT have shown much better durability, especially when properly maintained. Subaru now offers a 10-year/100,000-mile powertrain warranty on CVT repairs for qualifying vehicles, which speaks to their confidence in long-term reliability.

Electrical and Other Common Problems

Beyond mechanical issues, some Forester models have reported electrical gremlins and accessory failures.

AC Compressor Failure (2010–2013 Models)

Several 2010–2013 Forester models experienced premature AC compressor failure. Symptoms include weak cooling, loud noises from the engine bay, or complete loss of air conditioning.

Subaru issued a technical service bulletin (TSB) for this issue, and some owners received extended warranty coverage. Replacement can cost $800–$1,200, making it a notable expense if not covered.

Window Regulator Failure (2014–2018 Models)

Multiple owners of fourth-generation Foresters have reported window regulator issues, particularly with the driver’s side window. Symptoms include slow operation, strange noises, or the window falling into the door.

Subaru addressed this with a redesigned regulator, and many repairs are covered under warranty if the vehicle is still eligible. Aftermarket replacements are available for around $100–$150 per door.

Check Engine Light and Oxygen Sensor Issues

Like many modern vehicles, Foresters are sensitive to oxygen sensor (O2 sensor) failures. A faulty O2 sensor can trigger the check engine light and reduce fuel efficiency.

While not a major repair ($200–$400), it’s a common maintenance item and should be addressed promptly to avoid long-term engine issues.

Best Subaru Forester Model Years

After analyzing reliability data, owner feedback, and repair frequencies, certain years stand out as the most dependable choices.

2014–2018 (Fourth Generation – Best Overall)

The 2014–2018 Forester models are widely considered the most reliable generation in the lineup. Key reasons include:

The 2.5L naturally aspirated engine (non-turbo) is particularly robust, with fewer oil consumption and carbon buildup issues compared to earlier turbo models. These vehicles also offer modern features like EyeSight driver assistance, Bluetooth, and a high ride height.

2019–2023 (Fifth Generation – Best for Technology and Safety)

The current-generation Forester (2019–present) takes reliability to the next level. Built on Subaru’s Global Platform, it offers:

Early reports indicate very few mechanical issues. The 2.5L engine is tuned for efficiency and smoothness, and the CVT is more responsive than in previous years. With a 5-star NHTSA safety rating and top-tier predicted reliability, the 2019 and newer models are excellent long-term investments.

2003–2005 (Second Generation – Reliable with Caveats)

The early second-generation Foresters (2003–2005) are often overlooked but can be solid choices if well-maintained. They avoid the head gasket issues that affected later 2006–2008 models and offer:

However, timing belt maintenance is critical. If you're considering one of these models, ensure the timing belt, water pump, and associated components have been replaced.

Worst Subaru Forester Model Years to Avoid

While most Foresters are dependable, a few years have earned poor reputations due to widespread mechanical problems.

2006–2008 (Second Generation – Head Gasket and Turbo Issues)

These model years are notorious for head gasket failures, especially in non-turbo models. Turbo XT versions add oil consumption and PCV problems to the mix. Even with maintenance, these engines are ticking time bombs for some owners.

If you're considering a used 2006–2008 Forester, insist on a full engine inspection, coolant analysis, and compression test. Avoid any vehicle with a history of