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 ↗2021 Subaru Crosstrek engine problems
severe Owners of the 2021 Subaru Crosstrek have filed 12 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
12
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2017 Crosstrek | 3 |
| 2018 Crosstrek | 16 |
| 2019 Crosstrek | 11 |
| 2021 Crosstrek (this page) | 12 |
| 2023 Crosstrek | 3 |
1crash
2fires
1injury
What stands out
Among the 6 model years of Subaru Crosstrek in our records for engine problems, this one ranks #2 by owner-complaint volume.
No new NHTSA engine complaint has been filed on this vehicle in over 5 years — the issue may be aging out of the active population.
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). (This is an revised version of the original bulletin.)
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 ↗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 ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2021 Subaru Crosstrek engine complaints cluster around several distinct problems. The coolant bypass valve malfunction is the most documented: owners describe engines running hot, loss of power above 3000 rpm, and disabled EyeSight driver aids—a service bulletin exists for this issue, though Subaru has not recalled it as of these complaint dates. Parts and labor run about $900 total.
Starter problems surface repeatedly: delayed or failed engine restart after auto stop-start shutdown, with one owner reporting the issue recurred within three months of a dealer replacement. The auto stop-start system itself generates complaints about violent shaking on transition.
More critical are the safety-level failures: two owners report engine fires with smoke and flames; one describes a complete stall and power loss on the highway. Another vehicle accelerated unexpectedly while braked, hitting a wall and injuring the driver. Engine stall events while lane-crossing, thermostat failure causing cutout, and a defective starter connector cable also appear. One owner reports their brand-new vehicle simply caught fire; insurance and manufacturer investigations reached no clear conclusion on cause.
Ignition coil premature wear under 60,000 miles forced a $1,500 repair including tow costs.
Same Subaru Crosstrek engine reports on nearby years: 2018 · 2019
Failure modes owners describe
Engine Coolant Bypass Valve Malfunction
The engine coolant bypass valve restricts coolant flow to the engine, causing abnormally high engine temperatures. Owners report the vehicle entering a limited-performance mode, loss of power, and inability to exceed 3000 rpm. The check engine light illuminates, and the EyeSight driver-assistance system disables due to loss of engine control signals.
When: 2021 models onward; one owner reports timing in reference to forum discussions of issues since 2020
Symptoms owners cite: Engine running hotter than normal; Vehicle refuses to exceed 3000 rpm; Severe engine lag during acceleration; Check engine light on; EyeSight adaptive cruise control, pre-collision braking, and sway warning disabled; Potential for total engine failure
Codes mentioned: Check engine light code indicating bypass valve failure
Repairs/costs cited: Bypass valve replacement approximately $500; Subaru labor approximately $400-500. Service Bulletin MC-10208664-0001 issued.
Recalls/TSBs owners mention: Service Bulletin MC-10208664-0001 available; Subaru reportedly has not issued formal recall as of complaint date, despite pattern of failures across 2021+ model year vehicles
Starter Motor Delayed Engagement / Auto Stop-Start Malfunction
The starter fails to engage immediately when the driver releases the brake pedal after the engine has been shut down by the auto stop-start system. Delay increases as engine temperature rises and with longer drive time. Dealer replacement of starter does not resolve the issue. Creates a safety hazard when attempting to merge into traffic.
When: Occurs consistently with extended driving; one owner reports issue recurring within 3 months of dealer starter replacement
Symptoms owners cite: Engine hesitation or delayed restart after auto stop-start shutdown; Delay worsens with engine temperature increase; Engine hesitates enough to feel like it will not start on longer drives; No warning lights or diagnostic codes present; Safety concern when merging into traffic due to restart pause
Repairs/costs cited: Dealer replaced original starter; problem recurred within 3 months on replacement unit
Engine Stall with Loss of Power and Fire
Engine loses responsiveness to throttle input while driving at highway speed; check engine light activates. Engine completely loses power, vehicle will not shift into park, and smoke and flames emerge from the engine compartment. Fire ignites in engine bay. Insurance auditors unable to determine cause; manufacturer attributed fire to external influences.
When: Occurred during highway driving at 65 mph; no mileage specified
Symptoms owners cite: Check engine light on; Engine unresponsive to throttle input; Complete engine power loss; Transmission will not shift to park; Smoke and flames from engine compartment; Engine fire
Codes mentioned: Check engine light
Repairs/costs cited: Vehicle destroyed by fire; repair cost unknown
Recalls/TSBs owners mention: Manufacturer stated fire was result of external influences; third-party insurance auditors could not determine cause
Unexpected Acceleration During Parking
Vehicle accelerates unexpectedly while the brake pedal is depressed during parking maneuver. Vehicle collides with wall. Airbags deploy and driver sustains multiple injuries.
When: At approximately 1,300 miles
Symptoms owners cite: Unexpected acceleration despite brake pedal depression; Vehicle collision with wall; Airbag deployment
Repairs/costs cited: Vehicle towed to impound lot; damage extent not detailed
Recalls/TSBs owners mention: Manufacturer was not notified of the failure
Engine Bogging and Stall on Acceleration
Engine loses power and bogs down when throttle is depressed during highway driving. Engine stalls completely, requiring restart. Prior to this incident, the same engine bogging symptom occurred three or four times but recovered after the driver cycled the throttle.
When: No specific mileage; occurred during extended driving with previous episodes
Symptoms owners cite: Engine bogging when depressing gas pedal; Engine stall during lane crossing; Loss of power requiring restart
Ignition Coil Premature Failure
Engine coil deteriorates rapidly and fails with violent shuddering during engine start attempt. Vehicle will not start. Coil shows severe wear despite no external damage and proper maintenance history. Less than 60,000 miles and 5 years in service.
When: Less than 60,000 miles; 5 years in service
Symptoms owners cite: Violent shuddering when turning ignition key; Complete failure to start; Severely damaged ignition coil
Repairs/costs cited: Ignition coil replacement with towing approximately $1,500 total
Electronic Thermostat Failure with Engine Cutout
Faulty electronic thermostat causes the cooling control system to fail. While driving at freeway speed, all warning lights illuminate and engine sputters and cuts out, creating a hazard on a busy multi-lane highway.
When: No mileage specified; occurred during freeway driving
Symptoms owners cite: All warning lights illuminating simultaneously; Engine sputtering; Complete engine cutout while driving; Loss of vehicle control on highway
Repairs/costs cited: Vehicle towed; repair cost not specified
Starter Connector Cable Defect with Engine Stall
Defective connector cable to the starter motor causes engine to stall unexpectedly and prevents restart. Dashboard illuminates with multiple alarm indicators. Subaru dealer identified and repaired the connector without charge.
When: No mileage specified; occurred at traffic stop
Symptoms owners cite: Engine shutdown while stopped; Dashboard illuminates with multiple alarms; Engine will not restart
Repairs/costs cited: Starter connector cable replaced at no cost by Subaru dealer
Recalls/TSBs owners mention: Dealer repaired defective connector cable at no charge
Auto Stop-Start Violent Shaking
The auto stop-start function causes the entire vehicle to shake violently when the engine transitions from off to on. Shaking is most severe when the vehicle is stopped and the system re-engages while the driver has their foot on the brake.
When: Occurs with every stop-start cycle; worsens when stopped with foot on brake
Symptoms owners cite: Violent shaking during engine start from stop-start shutdown; Shaking worse when vehicle is stationary with brake applied; Shaking occurs every stop-start cycle
Engine Compartment Fire
Engine compartment ignites and burns. No other details provided by owner.
When: Vehicle described as brand new; no mileage specified
Symptoms owners cite: Engine fire; Flames from engine compartment
Repairs/costs cited: Vehicle destroyed; repair cost unknown
Intermittent Total Power Loss
Vehicle experiences brief but complete loss of engine power while driving. Power loss lasts approximately half a mile before power is restored.
When: No mileage specified; occurred during highway driving
Symptoms owners cite: Complete loss of engine power while driving; Duration approximately 0.5 mile
Synthesized from 12 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
The engine stop start function causes the entire car to shake when going from engine off to engine on. It is worse when you are stopped and the stop start re-engages while your foot is on the brake.
My brand new Subaru ignited in the engine compartment, burst into flames and exploded while I was driving it.
Had engine trouble with your 2021 Subaru Crosstrek?
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 2021 Subaru Crosstrek?
It's a meaningful issue. 12 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 12 complaints filed, engine issues most often appear around 1,300 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/2021/Subaru/Crosstrek.
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.