The 2016 WRX STI is a high-strung rally-bred performance car with the legendary EJ257 2.5L boxer turbo. Known for exceptional handling and raw driving experience, but the EJ motor is at end-of-life engineering-wise and suffers significant reliability issues under stress or neglect.
Ringland Failure / Spun Rod Bearings (Catastrophic Engine Damage)
Occasional · high severityTypical onset: 40,000-80,000 mi
Symptoms: sudden loss of power and misfires, knock/rattle from lower engine, metallic debris in oil, cylinder 4 misfire code most common, blue smoke on deceleration
Fix: EJ257 is notoriously fragile under detonation, poor fuel, or aggressive tuning. Ringland failure (piston ring breaks) or spun bearings typically means full short block replacement or complete rebuild. 18-25 hours labor depending on shop removing motor vs in-chassis work. Most opt for forged short block upgrade at this point.
Estimated cost: $6,500-12,000
Turbocharger Failure (IHI VF48)
Occasional · medium severityTypical onset: 70,000-120,000 mi
Symptoms: loss of boost pressure, excessive blue/white smoke, loud turbo whistle or grinding, oil consumption increases, P0046 or P0047 boost control codes
Fix: OEM IHI turbos develop shaft play or compressor wheel damage, especially if oil changes neglected or engine run low on oil. Replacement involves 8-12 hours labor including exhaust work, coolant lines, and oil feed/return. Many upgrade to aftermarket at this point.
Estimated cost: $2,200-4,500
Head Gasket Seepage / Failure
Common · medium severityTypical onset: 60,000-100,000 mi
Symptoms: external oil weeping from head/block mating surface, coolant consumption without visible leaks, white exhaust smoke on cold start, overheating under load, milky oil cap residue
Fix: Classic Subaru weak point, though less catastrophic than older models. External seepage often progresses to internal failure. Requires engine-out service or very tight in-chassis work. 16-22 hours for both sides, includes timing components and water pump while apart. Multi-layer steel gasket upgrade highly recommended.
Estimated cost: $3,500-5,500
Transmission Synchro Wear (1st and 2nd Gear)
Common · medium severityTypical onset: 50,000-90,000 mi
Symptoms: grinding into 2nd gear when cold, difficult 1st gear engagement, gear popout under load, notchy shifting at high RPM, clutch pedal feels normal but shifts poorly
Fix: Six-speed manual has weak brass synchros that wear from aggressive driving or clutch dump abuse. Repair requires transmission removal and full disassembly. 12-16 hours labor. Most replace all synchros and inspect shift forks while open. OEM parts only—aftermarket synchros fail quickly.
Estimated cost: $2,800-4,200
Transmission Oil Cooler Line Failure
Occasional · high severityTypical onset: 60,000-100,000 mi
Symptoms: sudden transmission oil leak underneath, lines corroded or cracked at fittings, burnt smell after driving, visible oil spray on undercarriage, transmission slipping or grinding from low fluid
Fix: Hard lines from transmission to front-mount cooler crack from road salt corrosion or stone impact. If caught early, 2-3 hours to replace lines. If driven low on fluid, transmission damage can occur requiring full rebuild. Inspect lines annually in salt states.
Estimated cost: $400-800
Clutch and Throwout Bearing Failure
Common · medium severityTypical onset: 40,000-70,000 mi
Symptoms: clutch pedal chattering or squeaking, grinding noise when pedal depressed, difficulty shifting all gears, clutch slipping under WOT, burning smell
Fix: OEM clutch is marginal for the torque, especially if launching hard. Throwout bearing chirps before failing. Clutch job is 6-8 hours transmission-out labor. Most upgrade to ACT or Exedy Stage 1/2 and replace rear main seal while apart. Flywheel resurface or replacement adds 1 hour and $150-400.
Estimated cost: $1,800-2,800
Engine Mounts and Transmission Mount Deterioration
Common · low severityTypical onset: 50,000-80,000 mi
Symptoms: excessive drivetrain movement on launch, clunking when shifting or accelerating, vibration at idle, visible torn rubber on mounts, wheel hop during aggressive starts
Fix: Performance driving accelerates mount wear. Pitch-stop mount (front) and transmission mount fail first. Each mount is 1-2 hours labor. Upgrading to stiffer aftermarket mounts reduces movement but increases NVH. Group mount replacement typically 4-5 hours total.
Estimated cost: $800-1,400
Buy only if you have $5K-10K set aside for inevitable engine work, find a bone-stock low-mile example, and can verify religious maintenance—modified or abused STIs are grenades.
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.