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 ↗2019 Subaru Ascent engine problems
moderate Owners of the 2019 Subaru Ascent have filed 21 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
21
Recalls
0
Avg fix
$3,100
| Model year | engine complaints |
|---|---|
| 2019 Ascent (this page) | 21 |
| 2020 Ascent | 10 |
| 2021 Ascent | 5 |
| 2022 Ascent | 5 |
When does it fail?
Of the 21 engine complaints filed for the 2019 Subaru Ascent, here's the actual mileage breakdown — failures cluster heaviest at 0-25,000 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.
What stands out
Of the 4 model years of Subaru Ascent we track for engine problems, this one carries the most owner complaints on file — 21.
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 outlines the diagnostic and repair procedure for white smoke emitted from the exhaust after startup.
full bulletin at NHTSA ↗This bulletin announces the design change made to the exhaust manifold flange nut material that has been changed from stainless steel to medium carbon steel. This change also necessitates a revised tightening torque specification. (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 ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The narratives describe a pattern of serious engine issues across 2019 Ascents. Excessive blue or white smoke on startup—present on most days since purchase for some owners—appears widespread and well-known to Subaru service advisors, yet the manufacturer reportedly claims there is no fix. One owner with asthma reports severe attacks triggered by noxious fumes.
Catastrophic engine failure under light towing (4,130 pounds) produced rapid valve-knock escalation, oil overheating, and warning-light activation, culminating in stalling and creating a traffic hazard. Subaru blamed excessive weight despite the load being lighter than the camper weight Subaru uses in its own marketing.
Several owners report fuel-in-oil contamination: oil levels rising above the max mark with detectable fuel odor on the dipstick, and raw fuel smell entering the cabin, suggesting failed fuel injectors or a combustion-sealing issue.
Cracked exhaust manifolds and Y pipes with poor welds introduce exhaust fumes into the cabin, sometimes accompanied by loud ticking on cold startup. One owner notes Subaru has recalled similar defects on other models.
Post-recall fuel-pump replacement has left at least one owner with rough idle and rough running. Engine stutter, stalling at traffic lights, violent shaking during highway acceleration with automatic emergency braking activation, and overhead-unit stalling at low speeds round out the failures reported.
Same Subaru Ascent engine reports on nearby years: 2020
Failure modes owners describe
Excessive smoke on startup
Blue, gray, or white plume of smoke from the exhaust during cold starts, sometimes lasting several minutes. Owners report this occurs intermittently or on most days since purchase. Strong noxious odor present. One owner notes severe asthma attacks triggered by the fumes. Dealer service unable to replicate the issue on multiple occasions.
When: At startup, particularly after overnight or extended parking
Symptoms owners cite: Blue/gray/white plume of smoke from exhaust; Strong chemical or noxious odor; Occurs intermittently or regularly after vehicle purchase; Fumes enter cabin
Repairs/costs cited: One owner had an unspecified part replaced at first dealer visit, no remedy thereafter. Another dealer stated Subaru of America has acknowledged the issue but stated there is no fix. One owner references another owner's engine replacement after months of evaluation.
Recalls/TSBs owners mention: Subaru of America reportedly aware of issue but states no fix available. Service advisors indicate manufacturer declined parts replacement attempts.
Check Engine Light with engine instability
Check Engine Light illuminated while driving, causing EyeSight system to disable and vehicle speed limited to 60 mph or below. One narrative mentions early production models had missing bolts in the engine airtight compartment. Dealership unable to diagnose the root cause in at least one instance.
When: While driving on freeway
Symptoms owners cite: Check Engine Light activated suddenly; EyeSight system disabled; Vehicle becomes unstable and limited to 60 mph maximum; Multiple dash error alerts
Repairs/costs cited: Owner researched online forums and identified missing bolts in engine airtight compartment as possible cause on early models. No dealer repair documented in narratives.
Recalls/TSBs owners mention: No TSB or recall issued according to owner complaint. No formal Subaru response documented.
Engine knock, stall, and catastrophic overheating while towing
Owner heard valve-flutter-like knocking that escalated rapidly while towing a 4130-pound camper at 45–50 mph on an incline. Oil temperature rose dramatically; oil warning light illuminated after pulling over. Subaru investigations concluded excessive weight was cause, though owner disputes towing within spec. Owner also reports engine revved hard on inclines and struggled to find proper gear while towing on previous trips.
When: While towing on incline, around 39,000 miles
Symptoms owners cite: Loud knocking noise that escalated to alarming levels; Oil temperature rising rapidly; Oil warning light illuminated; Engine struggling to find gear while towing; Hard revving on slight inclines while towing
Repairs/costs cited: Vehicle towed to Subaru Las Vegas. Battery found dead. Repair status and costs not documented; owner requested engine replacement under warranty.
Recalls/TSBs owners mention: Subaru of America and Subaru of Las Vegas completed two investigations concluding excessive towing weight was cause. Owner disputes this conclusion with camper registration and specs showing vehicle within Airstream marketing camper specifications. Subaru has not provided copies of investigation reports. Warranty coverage status unclear.
Cracked or defective exhaust manifold/Y pipe with poor welds
Y pipe connecting exhaust from engine to turbocharger has developed cracks from poor welds. Started with loud noise during warm-up that quieted as engine warmed; later progressed to exhaust fumes entering cabin. Owner had to air out vehicle after startup before driving. Safety concern noted due to fume infiltration.
When: 8–12 months after purchase; fumes detected later
Symptoms owners cite: Loud noise during engine warm-up phase; Quiet operation once warmed up; Exhaust fumes detected inside cabin; No loss of power or MPG initially
Repairs/costs cited: Subaru offered partial credit for repair. Owner notes Subaru has issued recalls for similar cracked exhaust manifolds on other model cars.
Recalls/TSBs owners mention: Partial credit offered for repair, not full warranty coverage.
Exhaust manifold lines faulty with cabin fume infiltration
Exhaust fumes entering cabin while engine idling. Loud ticking sound from exhaust system immediately after starting. Local dealer determined exhaust manifold lines were faulty and required replacement. Vehicle not repaired; manufacturer notified but no assistance provided.
When: At 120,000 miles
Symptoms owners cite: Exhaust fumes entering cabin during idle; Loud ticking from exhaust system on startup
Repairs/costs cited: Dealer determined exhaust manifold lines faulty and needed replacement. Repair not completed.
Recalls/TSBs owners mention: Manufacturer notified but no assistance provided.
Engine stutter and stalling at traffic lights
Engine stutters during deceleration and when slowing to stops at traffic lights. On multiple occasions, engine has stalled and required restart. Owner ensures proper warm-up (7–10 minutes) before driving. Problem began recently. Owner concerned about sudden stall while driving causing accident.
When: Recently; timing and mileage not specified
Symptoms owners cite: Engine stuttering while decelerating; Stalling at traffic lights; Requires manual restart; Occurs despite adequate warm-up time
Engine shaking and loss of power during acceleration
During highway passing attempt, vehicle shook violently with engine stutter. Sudden loud bang jolted the car; crash avoidance system activated emergency brakes automatically. Engine shut off; multiple warning lights (Emergency collision warning, EyeSight, Check Engine, RAB) illuminated. Parking brake engaged and disengaged without human input. Multiple-car fishtail occurred behind vehicle.
When: While accelerating at 70 mph during highway passing
Symptoms owners cite: Violent shaking during acceleration; Engine stutter; Sudden loud bang; Automatic emergency braking activation; Engine shutdown; Multiple warning lights; Parking brake automatic activation; Subsequent fishtail in traffic
Repairs/costs cited: Dealer calls not returned. Vehicle repair status unknown.
Recalls/TSBs owners mention: Subaru has not responded per owner complaint.
Fuel in oil mixture
Owner detected strong fuel smell entering cabin while driving and from exhaust. Upon checking oil dipstick, detected fuel odor originating there. Oil level found to be well above the high mark on dipstick, indicating fuel mixing with oil. Risk of engine damage noted by owner.
When: Timing not specified
Symptoms owners cite: Fresh fuel smell in cabin; Fuel smell from exhaust; Fuel odor detected on oil dipstick; Oil level elevated above high mark
Raw fuel smell at idle and reduced fuel economy
Strong raw gasoline smell when vehicle idles or after being driven and parked. Smell enters cabin through vents and fills garage. Fuel economy negatively affected; appears lower than normal.
When: At idle and after parking
Symptoms owners cite: Raw gasoline smell at idle; Strong fuel smell after parking; Smell enters cabin vents; Reduced fuel economy
Idle rough running after fuel pump replacement under recall
After fuel pump replacement performed under recall, vehicle began idling rough and running rough shortly thereafter. Owner researched and found another lawsuit or issue with same fuel pump having identical symptoms.
When: Shortly after fuel pump replacement under recall service
Symptoms owners cite: Rough idle; Rough running condition
Repairs/costs cited: Fuel pump replaced under recent recall.
Recalls/TSBs owners mention: Fuel pump recall issued, but replacement appears to create or fail to resolve rough running condition.
Overhead unit failure causing abnormal noise and stalling
While driving at low speed (10 mph), abnormal noise occurred and vehicle stalled. Vehicle restarted and functioned normally. Napleton Subaru dealer diagnosed overhead unit needed replacement and completed the repair. Janesville Subaru dealer suggested stabilizer bar lubrication (conflicting diagnosis).
When: At 3,801 miles
Symptoms owners cite: Abnormal noise at low speed; Vehicle stalling
Repairs/costs cited: Napleton Subaru replaced overhead unit. Janesville Subaru suggested stabilizer bar lubrication.
Recalls/TSBs owners mention: Manufacturer opened two case numbers: 144125212915 and 1-459841535478.
Oil pan leaking and recurring seal failure
Oil pan found leaking during dealership inspection in December 2023 and resealed. Same problem recurred approximately 8 months later and was resealed again. Owner notes this appears to be a recurring problem on similar vehicles.
When: First at December 2023 inspection; again 8 months later
Symptoms owners cite: Oil pan leak
Repairs/costs cited: Oil pan resealed twice at dealership. Problem recurred after first repair.
Transmission slipping on inclines and flat acceleration
Transmission slipping, especially while climbing inclines, though also occurs on flat surfaces during acceleration.
When: Not specified
Symptoms owners cite: Transmission slipping on inclines; Transmission slipping during flat-surface acceleration
Engine shaking while stationary
Vehicle shakes violently when stopped on the road or when brakes are engaged. Check Engine Light flashes when engine is starting.
When: While stationary with brakes engaged
Symptoms owners cite: Violent shaking while stopped; Violent shaking when brakes engaged; Check Engine Light flashing during startup
Synthesized from 21 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
The engine keeps stuttering when driving and slowing down to stop at a traffic light. Couple of times, it should shut down and I have to restart the car. I do ensure the car is warmed up to a minimum of 7-10 minutes before starting. It only started recently but I am worried that this will happen more and suddenly stop when driving and me getting involved in an accident.
The Y pipe that connects the exhaust from the engine to the turbo charger, has cracks from poor welds. It happened 8-12 months ago we started to notice that during warm up our Ascent would sound real loud then quiet down once it warmed up. We didn’t know there was an issue as there were no lights that came on and we had no loss of power or MPG. The safety issue would be that we finally took the…
Had engine trouble with your 2019 Subaru Ascent?
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 2019 Subaru Ascent?
It's a documented issue but not catastrophic. 21 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?
Based on the 21 complaints filed, engine issues most often appear around 26,574 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/2019/Subaru/Ascent.
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.