The fifth-generation Forester pairs Subaru's proven symmetrical AWD with a mild hybrid system. The 2.0-litre FB20 boxer engine is mated to a small electric motor and lithium-ion battery, adding modest torque assistance at low speeds. In Europe, this is the only powertrain offered. The e-BOXER system is simple in concept but introduces additional electrical complexity compared to the previous SJ generation.
Genuine symmetrical AWD standard
Refined FB20 engine, timing chain
Thermo control valve defect
Windshield prone to cracking
Buy if: You want a capable all-weather SUV with standard AWD and can confirm the thermo control valve has been addressed.
Avoid if: You mostly do short urban trips (12V battery drain, CVT issues worsen) or need cheap windshield replacements (EyeSight recalibration adds cost).
Expected Annual Maintenance Costs
Common Problems
Internal corrosion causes DTCs and check engine light, typically after 50,000-80,000 km · more· less
The thermo control valve (TCV) on 2019-2021 Foresters is prone to internal sensor corrosion. The stainless steel shaft corrodes over time, causing diagnostic trouble codes P2682 and P26A-series. Symptoms include check engine light, rough running, and in some cases engine overheating if the valve sticks in the wrong position. Subaru issued TSB 09-80-21R acknowledging the design flaw and introduced an updated valve with improved waterproofing and stainless steel internals from June 2021. Subaru has since extended the warranty on this component to 15 years or 240,000 km, so most used car buyers should still be covered. However, if buying outside this coverage window, replacement costs approximately 1,000-1,500 EUR including parts and labor. The part has been on extended backorder due to the volume of replacements needed.
Starting battery goes flat after 5-10 days of inactivity due to parasitic draw from hybrid systems · more· less
The e-BOXER Forester has two 12V batteries under the bonnet (48Ah and 45Ah). Owners widely report the starting battery going flat after just 5-10 days of not driving the car. The hybrid system's electronic control modules maintain a higher parasitic draw than non-hybrid Foresters. Some owners report the battery dying after as little as 4 days. The issue has been reported on brand-new vehicles under warranty. Subaru has acknowledged the problem but has not provided a definitive fix. Dealer replacements of the battery are common but the issue often recurs. Using a quality trickle charger (CTEK recommended) when the car is parked for extended periods is the most reliable workaround. Battery replacement costs 200-400 EUR depending on whether one or both batteries need replacement.
Acoustic glass develops spontaneous cracks without visible impact, requiring expensive replacement with EyeSight recalibration · more· less
Subaru switched to AGC acoustic windshield glass to reduce cabin noise, but this glass is notably fragile. Owners report spontaneous cracks appearing without any rock impact, often starting near the wiper area or black perimeter band. A class action lawsuit in the US resulted in a settlement covering 2019-2022 Foresters. In Europe, Subaru has been less forthcoming with warranty coverage for this issue. Replacement is expensive because the windshield must be OEM-spec acoustic glass, and the EyeSight cameras mounted to the windshield require professional recalibration afterward. Total cost for windshield replacement plus EyeSight recalibration runs 700-1,200 EUR depending on the source of glass and dealer labor rates.
Shuddering felt during light acceleration around 20-40 km/h as torque converter locks and unlocks · more· less
The Lineartronic CVT in the SK Forester is improved over the SJ generation but still exhibits shuddering during light acceleration, particularly around 20-40 km/h when the torque converter locks and unlocks. The issue is more noticeable in cold weather or when CVT fluid has degraded. Subaru has released software reflashes (TSBs) that improve but do not fully eliminate the sensation. Some owners have had torque converters replaced under warranty. Regular CVT fluid changes every 40,000 km are essential to minimize this. If the valve body is damaged, repair costs 1,200-2,500 EUR. Full CVT replacement (rare) would cost 5,000-7,000 EUR but this is unlikely on SK models unless severely neglected. The 10-year/160,000 km extended CVT warranty applies to many affected vehicles.
Safety system disables itself due to camera misalignment, condensation, or windshield issues · more· less
The EyeSight driver assistance system uses stereo cameras mounted to the windshield. These cameras are sensitive to alignment, condensation, and windshield condition. The system can disable itself during heavy rain, fog, or when the windshield is dirty or damaged. More concerning is that after windshield replacement or even minor front-end work, the cameras may need professional recalibration at a Subaru dealer (200-300 EUR). Some owners report persistent EyeSight shutdowns with no obvious cause, requiring camera module replacement at 500-800 EUR. This is more of a nuisance than a safety issue since the car drives normally without EyeSight, but the frequent warning messages are frustrating.
Touchscreen freezes, Apple CarPlay disconnects, and Bluetooth drops connection randomly · more· less
The Starlink infotainment system in the SK Forester has received numerous complaints about screen freezing, random reboots, Apple CarPlay not connecting or greying out, and Bluetooth audio dropouts. Software updates have improved but not resolved the issue for all owners. In severe cases where the head unit hardware fails completely (black screen, constant reboot loop), the entire unit must be replaced at 800-1,500 EUR. For intermittent software glitches, a dealer software update or factory reset may help at minimal cost (100-300 EUR diagnostic fee).
Generally reliable, but hybrid complexity and known defects add cost
The Forester SK e-BOXER is fundamentally sound, with the FB20 boxer engine proving durable and the symmetrical AWD system being well-proven. However, the thermo control valve defect affects a large number of 2019-2021 cars (check extended warranty coverage), the 12V battery drain is a persistent nuisance for infrequent drivers, and windshield replacements are expensive due to EyeSight recalibration. The CVT is improved over the previous generation but benefits from regular fluid changes. Most issues are manageable with awareness and preventive maintenance.
Recalls and Technical Service Bulletins
Fuel pump impeller failure (WRD-20 / WRG-21) - defective impeller can cause engine stalling (2019-2020 models)
Verify completed
Rear stabilizer bracket bolts loosening (WRD-21) - bolts may detach and contact brake pipe (2019 models)
Verify completed
Electronic power steering connector short circuit (WUC-88) - EPS loss of assist (early 2019 production, Dec 2018 - Jan 2019)
Verify completed
Thermo control valve extended warranty (TSB 09-80-21R) - sensor corrosion causing DTCs (2019-2021 models)
Warranty extended to 15 years / 240,000 km
Contact a Subaru dealer with the VIN to verify all recalls have been completed. The thermo control valve warranty extension is particularly important as it covers one of the most common and expensive repairs on this model.
Warranty Status
Factory warranty (3 years / 100,000 km)
Expired on 2019-2022 models
Thermo control valve extended warranty
15 years / 240,000 km from first registration
e-BOXER hybrid battery warranty
8 years / 160,000 km
Rust perforation warranty
12 years
Most 2019-2021 Foresters are outside their original 3-year factory warranty. However, the thermo control valve extended warranty (15 years) and hybrid battery warranty (8 years) may still provide coverage for the most expensive potential repairs. Verify coverage status with a Subaru dealer using the VIN.
This report is for informational purposes only and does not constitute professional advice. Estimates may be inaccurate. Always have a qualified specialist inspect the vehicle before purchase. We accept no liability for decisions made based on this information.