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 ↗2017 Subaru Forester engine problems
moderate Owners of the 2017 Subaru Forester have filed 23 NHTSA complaints about the engine, typically surfacing around 16,500 miles 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 →
Failure mileage
Complaints
23
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2013 Forester | 22 |
| 2014 Forester | 41 |
| 2015 Forester | 72 |
| 2016 Forester | 32 |
| 2017 Forester (this page) | 23 |
| 2018 Forester | 14 |
| 2019 Forester | 60 |
| 2020 Forester | 32 |
| 2021 Forester | 15 |
1crash
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 ↗This Bulletin provides the diagnostic procedure for the STARLINK® Remote Engine Start (RES).
full bulletin at NHTSA ↗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 ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners report multiple distinct engine and engine-related failures on 2017 Subaru Foresters. Sudden unintended acceleration emerges as a critical safety concern—one owner experienced uncontrolled acceleration while braking into a parking space, causing a collision, followed by an ECM software update at the dealer. Another describes loss of acceleration on the highway requiring a computer reset.
Excessive oil consumption is widespread. Owners with low mileage (under 20K miles) report the low-oil warning light illuminating within 4K miles of a 5K-mile service interval. One owner documented a quart of oil consumed in 1200 miles on a formal Subaru oil-consumption test; the dealer deemed it within spec but later replaced the short block under warranty. A second owner burned oil severely enough to require keeping spare quarts on hand.
Exhaust system failures dominate complaints—exhaust manifold bellows cracking and flexi pipes rupturing repeatedly, allowing fumes into the cabin through vents and AC. Owners report headaches and lightheadedness from inhaled exhaust. One replacement cost $1800 for a full manifold. Catalytic converter failure is cited repeatedly, with code P0420 documented. One owner paid $800 for a converter at an independent shop while a friend's identical car was covered free at Subaru; another's vehicle failed inspection due to rust on the converter.
Stalling and hesitation on acceleration—sometimes after braking, sometimes during turns with low fuel, sometimes on inclines—are reported by multiple owners. One experienced heavy smoke and a hole in the engine block at 20K miles, deemed a potential fire hazard. Another reports cam carrier leaks with no warning lights and characterizes the vehicle as unreliable.
Same Subaru Forester engine reports on nearby years: 2015 · 2016 · 2018 · 2019 · 2020
Failure modes owners describe
Sudden unintended acceleration (SUA)
Vehicle surges forward despite continued braking pressure, independent of driver input.
When: During braking to stop for parking
Symptoms owners cite: Forward surge despite increased braking effort; Vehicle unstoppable despite brake application; No dashboard warning lights before or after event
Repairs/costs cited: Dealer performed ECM (Engine Control Module) software update described as designed to address such problems. Diagnostic fee waived.
Recalls/TSBs owners mention: ECM update issued; Subaru declined detailed explanation of update purpose or effectiveness.
Excessive oil consumption
Engine burns oil at rates exceeding manufacturer specifications, triggering low-oil warnings prematurely.
When: As early as 2K-4K miles into 5K-mile service intervals; vehicles with under 20K total miles affected
Symptoms owners cite: Low oil level warning light on dipstick check; Oil level dropping 20% between two dipstick lines in 1200 miles of normal driving; Repeated low-oil warnings within same service interval
Repairs/costs cited: Owner documented consumption at ~1 quart per 5K-6K mile interval on short-block replacement; second owner required to carry spare quarts for long-distance travel.
Recalls/TSBs owners mention: Subaru dealer stated consumption within spec; short-block replacement performed under factory warranty in at least one case.
Exhaust manifold and flexi-pipe cracking
Exhaust manifold bellows and flexi pipes crack, allowing exhaust fumes to enter cabin.
When: Reported at 60K-160K miles; one pipe replaced at 60K miles lasted only ~1 year/30K miles before cracking again
Symptoms owners cite: Exhaust fumes in cabin during idle or low-speed driving; Lightheadedness and headaches from inhaled fumes; Visible crack on flexi pipe after removal of underbody covers
Repairs/costs cited: Full manifold replacement quoted at $1800; flexi pipe replacements required multiple times.
Recalls/TSBs owners mention: Turbo models received voluntary emissions recall (March 27, 2020); non-turbo vehicles not included despite reported failures.
Catalytic converter failure and cabin exhaust leaks
Catalytic converters fail prematurely and/or rust excessively; separate exhaust leak into cabin occurs independent of converter status.
When: Failures reported at 60K-156K miles; one failure at 140K miles
Symptoms owners cite: Check engine light with code P0420 (catalytic converter failure); Loud rattling noise from exhaust; Exhaust odor in passenger cabin via AC vents; Excessive rust on converter despite no prior rust noted during annual inspection
Codes mentioned: P0420
Repairs/costs cited: Replacement cost $800 at independent shop; one owner's friend had identical failure covered free by Subaru. Rust damage was attributed to plastic covers restricting air circulation around converter.
Recalls/TSBs owners mention: Warranty extension 09-84-22 researched by owner but not applied to their vehicle; dealer case manager allegedly provided false information about extension existence.
Stalling and hesitation on acceleration
Engine loses power, nearly stalls, or completely stalls during acceleration—particularly during turns, after braking, or on inclines.
When: Reported at various mileages; one incident at 4930 miles; ongoing issues on new vehicles
Symptoms owners cite: Vehicle stalls when attempting to accelerate after braking on highway; Loss of acceleration power, requiring flooring gas pedal; Stalling on hard left turns, especially with less than 1/4 tank of gas; Hesitation during acceleration worse with AC on; RPM surge to over 4500 and loud grinding noise on cold start (separate incident); Bucking and backfire-like failures during acceleration
Repairs/costs cited: One case treated with software update (no improvement reported); another resolved by filling gas tank; dealer told one owner computer needed reset in emergency situation.
Recalls/TSBs owners mention: Software update offered in at least one case; no other manufacturer response documented.
Engine block hole and internal damage
Engine developed a hole in block, allowing oil to escape and heavy smoke to fill cabin.
When: At approximately 20K miles
Symptoms owners cite: Check engine light illumination; Heavy smoke from air vents filling cabin; Smoke from under hood; Oil coating engine exterior
Repairs/costs cited: Dealer stated hole in block indicated faulty engine; vehicle characterized as fire hazard.
Condenser/compressor failure
Air conditioning condenser and compressor failure identified as causing sputtering.
When: Under 60K miles on newly purchased vehicle
Symptoms owners cite: Sputtering in vehicle operation
Repairs/costs cited: Dealership advised recall existed but was VIN-specific; parts replacement required.
Recalls/TSBs owners mention: Recall issued but limited to specific VINs, not all 2017 models with same issue.
Cam carrier leak
Cam carrier develops leak, indicating unreliability; no warning lights alert owner.
When: Mileage not specified
Symptoms owners cite: No warning lights prior to detection; Oil leak from cam carrier
Repairs/costs cited: Detected and confirmed by Subaru dealership during service.
Recalls/TSBs owners mention: Owner notes this appears to be a recurring issue for many Subaru vehicles.
Synthesized from 23 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 0 most recent
Had engine trouble with your 2017 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 2017 Subaru Forester?
It's a documented issue but not catastrophic. 23 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Across the 10 complaints that reported odometer mileage, most engine failures cluster between 4,930 and 90,000 miles, with the median around 16,500. A quarter of owners report trouble before 4,930; a quarter make it past 90,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
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/2017/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.