This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel injectors and internal engine components (e.g. intake valves and / or manifold, and combustion chambers). (This is an revised version of the original bulletin.)
full bulletin at NHTSA ↗2018 Subaru Forester engine problems
severe Owners of the 2018 Subaru Forester have filed 14 NHTSA complaints about the engine at roughly $3,100 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See engine across all vehicles →
Complaints
14
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2014 Forester | 41 |
| 2015 Forester | 72 |
| 2016 Forester | 32 |
| 2017 Forester | 23 |
| 2018 Forester (this page) | 14 |
| 2019 Forester | 60 |
| 2020 Forester | 32 |
| 2021 Forester | 15 |
| 2022 Forester | 4 |
1crash
1fire
When does it fail?
Of the 14 engine complaints filed for the 2018 Subaru Forester, here's the actual mileage breakdown — failures cluster heaviest at 25,000-50,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
This bulletin provides updated parts information and a service procedure to follow for removing accumulated carbon deposits from fuel injectors and internal engine components (e.g. intake valves and / or manifold, and combustion chambers).
full bulletin at NHTSA ↗This bulletin announces the diagnostic procedures to be used when DTCs B1571(REFERENCE CODE INCOMPATIBILITY IMMOBILIZER CM TO ECM) and B1572(IMM CIRCUIT EXCEPT ANTENNA CIRCUIT) are detected by Keyless Access with Push Button Start(KACM).
full bulletin at NHTSA ↗In the interest of customer satisfaction, Subaru of America, Inc. (Subaru) is initiating a new voluntary emissions recall for certain 2018 model year WRX and Forester vehicles and certain 2019 MY WRX equipped with a 2.0L turbo engine.
full bulletin at NHTSA ↗This Bulletin provides the diagnostic procedure for the STARLINK® Remote Engine Start (RES).
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Engine power loss is a recurring complaint: at least three owners report sudden loss of power while driving, including two on the highway at 70 mph that forced emergency shoulder stops. One owner's power loss involved both catalytic converters failing in sequence at 85k miles—just beyond Subaru's 80k mile warranty—leaving him thousands of dollars out of pocket. Dealers have found no fault in other power-loss cases.
Exhaust system problems include manifold separation from the engine block (causing cabin exhaust entry), manifold gasket leaks that whistle on cold start, and fuel entering the oil—the last reported at just 6,000 miles. An owner felt sick for weeks from cabin exhaust before diagnosing the manifold separation; the dealer acknowledged it's a known problem but refused to call it a defect.
AC compressor seizure with belt failure appears twice, with one owner reporting flames shooting from the compressor. Camshaft seal leaks occur at 37k miles; Subaru recently switched from felt to silicone seals, and owners report the new design is failing prematurely.
CVT and throttle control failures include one low-gear failure (recorded by owner, shot down by dealer because no diagnostic code exists) and delayed throttle response that turned into sudden lurching during low-speed driving. One owner experienced unintended acceleration shifting from neutral to drive at a car wash. Ticking on cold start with reduced acceleration at 74k miles suggests AVCS solenoid wear, though unconfirmed by dealers.
Same Subaru Forester engine reports on nearby years: 2015 · 2016 · 2017 · 2019 · 2020
Failure modes owners describe
Catalytic converter failure
Sudden loss of engine power on the highway due to failed catalytic converters. One owner reported both catalytic converters failed in sequence, with the car dying in the left lane at high speed. Failure occurred at 85k miles, just beyond Subaru's 80k mile warranty.
When: 85,000 miles
Symptoms owners cite: sudden loss of engine power at highway speed; all warning lights illuminated; car dies without warning
Repairs/costs cited: Both catalytic converters replaced; owner reports thousands of dollars in repair costs; Subaru experiencing parts supply delays
Recalls/TSBs owners mention: Catalytic converter coverage limited to 80k miles under Subaru warranty
Exhaust manifold warping and separation
Exhaust manifold warps and separates from the engine block, allowing exhaust to enter the cabin. One owner reports feeling sick for weeks from cabin exhaust exposure. Dealer acknowledged the issue is known but refused to call it a defect.
When: Unknown mileage
Symptoms owners cite: exhaust smell entering cabin; occupant illness from exhaust exposure
Repairs/costs cited: Manifold replacement required; owner waiting for parts
Recalls/TSBs owners mention: No recall; dealer refused to acknowledge defect status
Exhaust manifold gasket leaks
Exhaust manifold gasket fails, allowing exhaust to leak. Occurs at multiple mileage intervals and is only audible during cold weather startup.
When: 30,000 miles and 65,000 miles in separate reports
Symptoms owners cite: whistling sound on cold start; sound disappears when engine warms up; exhaust smell
Repairs/costs cited: Gasket replacement required
Camshaft seal leak
Oil leaks from camshaft seal at low mileage. Subaru recently switched from felt seals to silicone seals, and seals are failing prematurely. Multiple owners of 2018–2019 Foresters report the same failure.
When: 37,000 miles
Symptoms owners cite: oil leak from camshaft area
Repairs/costs cited: Seal replacement covered under warranty at 37k miles
Recalls/TSBs owners mention: Warranty covers repair; manufacturer changed seal design from felt to silicone, but new design experiencing premature failure
AC compressor seizure and belt failure
AC compressor seizes, causing the serpentine belt to break. One owner reported the compressor sparked and shot 6–12 inch flames from the engine bay. Owner concerned about fire risk and noted a recall exists for the condenser on the same model year but not their specific VIN.
When: Unknown mileage
Symptoms owners cite: loud screaming noise from pulley; two loud pops; melted serpentine belt; AC compressor sparking; flames shooting from compressor area
Repairs/costs cited: AC compressor replacement required; owner has old compressor as evidence
Recalls/TSBs owners mention: Condenser recall exists for same model/year but not applied to owner's specific VIN
Fuel entering engine oil
Fuel contamination in engine oil detected during oil change. Owner also reported fuel fumes inside the vehicle.
When: 6,000 miles
Symptoms owners cite: fuel visible in engine oil; fuel odor inside cabin
Repairs/costs cited: Not diagnosed or repaired by dealer despite report to manufacturer
Recalls/TSBs owners mention: Manufacturer notified but no repair provided
Sudden power loss while driving
Engine loses power temporarily while driving, including on inclines and flat surfaces. One owner lost power on freeway at 70 mph and had to pull to shoulder; dealer found no fault. Multiple owners report similar issues with unpredictable power loss.
When: Unknown mileage; one at 70 mph freeway driving
Symptoms owners cite: sudden temporary loss of engine power; loss of power on inclines and flat surfaces; power loss at highway speeds without warning
Repairs/costs cited: Dealer unable to diagnose or find fault; owner limped to dealer on shoulder after losing power at 70 mph
Reduced acceleration and ticking on cold start
Ticking noise on cold startup along with reduced acceleration and torque. Owner suspects AVCS solenoid failure, though not confirmed by dealership. No check engine light.
When: 74,000 miles; began within last 6 months
Symptoms owners cite: ticking noise on cold start; reduced acceleration speed and torque; no check engine light or stored codes
Repairs/costs cited: Not confirmed by dealership; owner suspects AVCS solenoids
Delayed throttle response and unintended acceleration
Car does not respond to gentle throttle input for 2–4 seconds, then lurches forward with excessive force as if full throttle applied. Occurs at random times, becoming more frequent over time. No warning lights.
When: Issue began 2 years prior, then recurred 6 times in 50 miles of city driving
Symptoms owners cite: 2–4 second delay in throttle response; sudden uncontrolled forward lurch after delay; no warning lights
Repairs/costs cited: Dealer initially said nothing wrong when first reported 2 years ago
Defective low gear (CVT)
CVT low gear fails to engage and does not slow vehicle during descent. Owner tested in Colorado mountains and recorded multiple failures on Texas hills. No diagnostic code exists for low gear failure, so diagnostic machines cannot detect it. Manufacturer and dealer refused to acknowledge defect or provide repair.
When: 21 days after purchase
Symptoms owners cite: low gear does not engage when selected; vehicle does not slow down on descents; failure reproduced multiple times on slopes
Repairs/costs cited: No repair provided; owner limited to 40 mph on mountain switchbacks
Recalls/TSBs owners mention: Manufacturer and dealer refused to acknowledge defect or repair; no diagnostic code exists for this failure mode
Unintended acceleration from neutral
After exiting car wash with vehicle in neutral, owner shifted to drive and car accelerated into the street at high speed without foot on accelerator pedal.
When: Unknown mileage; occurred after car wash
Symptoms owners cite: unintended acceleration from drive shift; acceleration occurs without driver input on throttle
Synthesized from 14 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
We were driving at 70mph on the freeway, left lane, and suddenly the car lost power as if the fuel pump went out. We had to suddenly get over to the shoulder of the freeway, almost got hit, then limped along the shoulder until we called a tow truck which towed us 40 miles to Subaru dealer. The dealer looked at the car and "couldn't find anything." Now we are afraid to drive the car.
When driving, sometimes my car loses power temporarily. It happens at times when I am going up an incline, but it has also happened on flat surfaces.
Had engine trouble with your 2018 Subaru Forester?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2018 Subaru Forester?
It's a meaningful issue. 14 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $3,100.
At what mileage does the engine typically fail?
Based on the 14 complaints filed, engine issues most often appear around 30,320 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2018/Subaru/Forester.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.