This bulletin announces the availability of reprogramming files for the Engine Control Module (ECM) for certain vehicles equipped with 3.6L engines.
full bulletin at NHTSA ↗2018 Subaru Outback engine problems
severe Owners of the 2018 Subaru Outback have filed 15 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
15
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2014 Outback | 28 |
| 2015 Outback | 25 |
| 2016 Outback | 33 |
| 2017 Outback | 14 |
| 2018 Outback (this page) | 15 |
| 2019 Outback | 16 |
| 2020 Outback | 18 |
| 2021 Outback | 7 |
| 2022 Outback | 8 |
1crash
1fire
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 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 announces the diagnostic procedures to be used when DTCs P2096 (POST CATALYST FUEL TRIM SYSTEM TOO LEAN BANK 1) and P2097 (POST CATALYST FUEL TRIM SYSTEM TOO RICH BANK 1) are detected by the Engine Control Module (ECM).
full bulletin at NHTSA ↗This Service Information Bulletin provides the Service Manual Correction to the diagnostic procedure for DTC B2A16 (Immobilizer Key Collation Diagnosis).
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners report the 2018 Outback's engine quits unexpectedly at road speed with no warning, leaving them coasting to the shoulder. The engine restarts normally but loses power steering and braking before it does. Dealerships acknowledge Subaru knows about the stalling but refuse to repair it—one owner's dealership told him to just keep the fuel tank above half-full. When no codes appear on scan, the dealer calls it a stall with no fix needed.
Coolant is another chronic complaint: owners say they lose about half a gallon monthly from new with zero visible leaks and a strong burning smell. Subaru and dealerships call this normal for the 2.5L and won't fix it.
Multiple owners report the catalytic converter flex joint leaks exhaust directly into the cabin for months or years, causing nausea, burning lungs, and difficulty breathing. Two independent shops confirmed the diagnosis; the dealership brushed them off.
One vehicle caught fire while driving. Another accelerated from a complete stop without pedal input and hit a tool box through a garage wall. A third accelerated wildly while parked and idling.
Cam tower seals fail consistently between 60,000 and 90,000 miles, costing over $3,000 to fix—well past the 60,000-mile warranty. Oil leaks from valve seals also repeat failures within 25,000 miles, and the low-oil warning never came on until inspection.
Same Subaru Outback engine reports on nearby years: 2015 · 2016 · 2017 · 2019 · 2020
Failure modes owners describe
Unexplained engine stalling while driving
Engine cuts off unexpectedly at speed with full electrical restart capability. Dealership acknowledged Subaru awareness of the issue but offered no repair. Owners report the problem ceased when fuel tank kept above half-full, suggesting a fuel-system sensor or low-fuel cutoff malfunction. No diagnostic codes retrieved during dealership inspection despite stalling events.
When: Multiple occurrences starting early in vehicle ownership; 15 miles into trip at 45 MPH
Symptoms owners cite: Engine cuts off while driving; Vehicle restarts after pulling to side of road; Loss of power steering and braking when engine shuts off; Inaccurate 'miles to empty' gauge
Repairs/costs cited: Field Service Engineer indicated fuel-system component failure as likely cause but dealership refused repair, citing internal cost concerns
Recalls/TSBs owners mention: Subaru acknowledged awareness; dealership advised keeping fuel tank above half-full as workaround
Coolant loss with burning smell
Vehicles losing half a gallon of coolant monthly from new with no visible leaks and strong burning-coolant odor. Dealer and Subaru state condition is normal for 2.5L engine and cause cannot be identified. No repair offered; ongoing topping-off required.
When: Since new vehicle purchase; ongoing monthly
Symptoms owners cite: Coolant level drops approximately half gallon per month; Strong burning-coolant odor; No visible leaks detected
Repairs/costs cited: Dealer only topping off system; no repair attempted
Recalls/TSBs owners mention: Subaru advised this is normal for 2.5L engine; cause cannot be identified
Exhaust leak at catalytic converter flex joint
Flex joint connecting to catalytic converter fails, routing exhaust directly into cabin for over three years. Issue reproduced and diagnosed by two independent mechanics. Dealership showed reluctance to inspect. Component subject to prior Subaru program bulletins (WUB-87, WUJ-95) and reported as commonly defective.
When: 3+ years duration
Symptoms owners cite: Exhaust fumes entering cabin; Coughing, nausea; Burning eyes, nose, lungs, chest; Foul odor; Difficulty breathing
Repairs/costs cited: Two independent mechanics confirmed diagnosis and reproduction
Recalls/TSBs owners mention: Subaru Program Bulletins WUB-87 and WUJ-95 exist for this component
Unintended acceleration events
Engine spontaneously accelerates to high revs without operator input. Occurred while vehicle was parked and idling (waiting for passengers), and again during fish-tailing on slick road. No mechanical obstruction found at accelerator. One event occurred with vehicle at stop in garage.
When: While idling/parked and during road-handling event
Symptoms owners cite: Engine accelerates to very high revs without pedal input; Vehicle accelerates forward from stopped position; Red exclamation warning symbol appeared on dashboard after one incident
Repairs/costs cited: No inspection completed on any of these incidents
Inadequate coolant fill and low-fuel programming fault
Vehicles shipped with insufficient coolant, requiring immediate top-off as residual air is expelled. Owner reports risk of overheating or stall if following Subaru service intervals. Separate recall noted for low-fuel programming issue.
When: Immediately after purchase
Symptoms owners cite: Coolant level drops requiring immediate fill; Residual air expulsion from cooling system; Risk of overheating or stall before first scheduled inspection
Repairs/costs cited: Multiple dealers approached with no resolution offered
Recalls/TSBs owners mention: Recall issued for low-fuel programming
Valve seal failure with inadequate low-oil warning
Valve replacement performed at 135,000 miles for oil leak; same valve failed again within 24,000 miles (159,000 total mileage). No dashboard warning illuminated despite oil level dropping to empty on dipstick, only serviceability message appeared after mechanic inspection.
When: First failure at 135,000 miles; second failure at 159,000 miles
Symptoms owners cite: Oil leak from valve; Oil level depleted to empty on dipstick; No low-oil warning light despite empty level; Only serviceability message appeared
Repairs/costs cited: Valve replacement required twice within 24,000 miles
Engine fire during operation
Vehicle caught fire while driving, growing quickly to destroy the vehicle. Vehicle was well-maintained, low mileage for age, and in perfect working order before fire. Power loss and engine warning lights appeared before fire started.
When: One year after purchase; low mileage
Symptoms owners cite: Vehicle started losing power; Engine warning lights illuminated; Engine caught fire and grew rapidly
Repairs/costs cited: Vehicle destroyed; no inspection completed
Cam tower seal failure
Cam tower seal fails at high rate on 2018 Outbacks, typically between 60,000 and 90,000 miles. Repair cost typically exceeds $3,000. Issue occurs consistently outside warranty coverage window despite standard warranty extending to 60,000 miles.
When: Typically 60,000–90,000 miles
Symptoms owners cite: Cam tower seal leak
Repairs/costs cited: Repair cost typically higher than $3,000
Recalls/TSBs owners mention: Standard warranty covers repair up to 60,000 miles only
Synthesized from 15 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 2018 Subaru Outback?
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 Outback?
It's a meaningful issue. 15 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 15 complaints filed, engine issues most often appear around 10,175 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/Outback.
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.