2021 SUBARU WRX

Typical onset: 40,000-80,000 mi

Symptoms: Sudden loss of power, Heavy white or blue smoke from exhaust, Cylinder 4 misfire code (P0304), Loud rattling or knocking from engine, Metal shavings in oil

Fix: Complete engine rebuild or short block replacement required. 18-24 labor hours for short block swap including turbo removal, wiring harness work, timing components. If caught early before bearing damage, can sometimes get away with piston/ring replacement on that cylinder (12-16 hours), but full teardown recommended to inspect bearings.

Estimated cost: $6,500-12,000

Typical onset: 50,000-90,000 mi

Symptoms: Deep knocking sound on cold start that goes away when warm, Metallic ticking that worsens under load, Low oil pressure warning, Metal debris in oil filter during changes, Complete engine seizure if ignored

Fix: Requires full engine teardown to measure bearing clearances and replace rod bearings. If crank is scored, needs machining or replacement. 20-26 labor hours for complete lower-end rebuild. Many techs recommend full short block at this point since you're already tearing it down.

Estimated cost: $5,000-9,500

Typical onset: 30,000-70,000 mi

Symptoms: Clunking when shifting or accelerating from stop, Excessive driveline vibration, Shifter slop increases, Visible torn rubber on mount inspection

Fix: Rear transmission mount replacement. Straightforward job on a lift. 1.5-2.5 labor hours depending on whether you're doing just the pitch mount or all motor mounts while you're in there. OEM or upgraded polyurethane options available.

Estimated cost: $250-600

Typical onset: 40,000-80,000 mi

Symptoms: Transmission fluid puddle under car (front-center), Low transmission fluid warning, Burnt smell when parking after highway driving, Hard shifting or slipping if fluid level drops significantly

Fix: Replace cooler lines and check connections at transmission and cooler. Lines corrode or crack at bends. 2-3 labor hours including fluid refill and system bleed. May need cooler itself if damaged.

Estimated cost: $400-800

Typical onset: 60,000-100,000 mi

Symptoms: Rough idle when cold, Hesitation during acceleration, Misfires under load (multiple cylinders), Reduced fuel economy, Check engine light for lean condition

Fix: Intake valve walnut blasting service. Remove intake manifold, blast each port with walnut media to remove carbon deposits. 4-6 labor hours. Direct injection engines have no fuel washing over valves, so carbon accumulates. Not catastrophic but affects performance.

Estimated cost: $500-900

Symptoms: Rattling sound at idle or light throttle (sounds like marbles), Rattle disappears under boost, No performance loss initially, Can progress to boost control issues or wastegate failure

Fix: Wastegate actuator rod play is common on IHI turbos. Can sometimes be adjusted, but often requires turbo removal and rebuild or replacement. 8-12 labor hours for turbo R&R if replacement needed. Many owners live with the rattle if boost control is still working properly.

Estimated cost: $1,200-2,800

Typical onset: 80,000-120,000 mi

Symptoms: External oil weeping at head/block interface, Coolant consumption without visible leaks, White smoke from exhaust on startup, Overheating under sustained load, Cross-contamination of oil and coolant in severe cases

Fix: Head gasket replacement both sides. Remove engine or lift body for proper access. 16-22 labor hours. Resurface heads, replace all gaskets, timing components, water pump while you're in there. FA20 is better than EJ25, but not immune, especially if overheated previously.

Estimated cost: $3,500-6,000