The 2020 Ascent with the FA24 turbo boxer suffers from catastrophic early piston ring failure and related bottom-end damage, particularly in 2019-2020 model years. Subaru issued extended warranty coverage, but many engines still grenade outside warranty periods, making this a high-risk used purchase.
Catastrophic Piston Ring / Engine Failure (FA24 Turbo)
Common · high severityTypical onset: 30,000-80,000 mi
Symptoms: Excessive oil consumption (1+ quart per 1,000 miles), Blue smoke on startup or acceleration, Loss of power, rough idle, misfires, Metal shavings in oil, eventual rod knock or seizure
Fix: Subaru extended warranty to 10yr/100k mi on powertrain for affected VINs, but many fall through cracks. Repair requires complete short block replacement (Subaru part), approximately 18-22 labor hours including R&I of transmission, exhaust, turbo, and accessories. Dealership-only job realistically.
Estimated cost: $8,000-12,000
Transmission Oil Cooler Leaks / Line Failures
Occasional · medium severityTypical onset: 40,000-90,000 mi
Symptoms: ATF puddles under vehicle, typically passenger side, Burnt ATF smell, dark red fluid on ground, Transmission overheating warnings on dash, Slipping or delayed shifts if fluid level drops
Fix: External cooler lines crack at crimp points or cooler itself develops pinhole leaks. Replace cooler and lines as assembly, flush system, 3-4 labor hours. Subaru revised part numbers in 2021+.
Estimated cost: $800-1,400
Transmission Control Module (TCM) Software / Hardware Faults
Occasional · medium severitySymptoms: Harsh or erratic shifts, especially 2-3 or 3-4, Limp mode, won't shift past 3rd gear, Check engine light with P0700, P0730 series codes, Intermittent no-start or crank-no-communication with TCM
Fix: Subaru issued TSB and recall for TCM reprogram (recall 20V-461). If software doesn't fix, TCM replacement required—dealer-only due to VIN pairing. 1.5-2 hours labor for diagnosis and flash, 2-3 hours if module replacement needed.
Estimated cost: $0 (recall) or $1,200-1,800 (module)
Fuel Pump Failure (Low-Pressure In-Tank)
Occasional · high severityTypical onset: 50,000-100,000 mi
Symptoms: No-start or long crank, especially when hot, Stalling at idle or low speed, Surging, hesitation under load, P0087 (fuel rail pressure too low)
Fix: Subaru recalled certain batches (recall 20V-372) for impeller defect. If outside recall VINs, requires fuel tank drop and pump module replacement, 3-4 labor hours. Check recall eligibility first.
Estimated cost: $0 (recall) or $900-1,500
Engine Mount / Transmission Mount Premature Wear
Common · low severityTypical onset: 60,000-100,000 mi
Symptoms: Excessive vibration at idle, especially in Drive, Clunk on throttle tip-in or deceleration, Visible sag or torn rubber on passenger-side engine mount, Shifter vibration
Fix: Rubber mounts deteriorate faster than expected, especially passenger-side torque mount. Replace as pairs (engine + trans), 2-3 labor hours. OEM Subaru parts recommended—aftermarket don't last.
Estimated cost: $500-900
Front Tie Rod End Premature Wear (Recall 21V-068)
Occasional · high severityTypical onset: 30,000-70,000 mi
Symptoms: Clunking over bumps, especially turning, Loose or wandering steering feel, Excessive play in wheel at 12-6 o'clock, Uneven tire wear on inner edges
Fix: Subaru recalled 2019-2022 Ascents for outer tie rod ball joint separation risk. Free replacement at dealer. If outside recall or tie rod already separated, requires tow. Alignment required after, 1.5-2 hours total.
Estimated cost: $0 (recall) or $400-700 (both sides + alignment)
Dashboard Wire Harness Chafing / Short Circuits
Rare · medium severitySymptoms: Intermittent gauge cluster glitches or blackouts, Airbag warning light, sometimes with popping sound behind dash, Burnt plastic smell from vents, Multiple electrical faults (radio, HVAC, etc.) at once
Fix: Recall 20V-074 addressed wire harness routing behind instrument cluster rubbing against bracket. Dealer reroutes and retapes harness, 1-2 hours. Fire risk if ignored.
Estimated cost: $0 (recall)
Hard pass unless you have written proof of short block replacement under warranty or can verify VIN is outside affected engine serial range—too many grenaded FA24s in the wild.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.