2005 SUBARU WRX STI

Typical onset: 60,000-120,000 mi

Symptoms: Misfires on cylinder #4, Loss of compression, Blue smoke from exhaust, Check engine light with P0304 code, Rough idle and power loss

Fix: Full engine rebuild required — pistons, rings, bearings, machine work on block and heads. Figure 25-35 labor hours for a complete teardown, inspection, and reassembly with upgraded forged internals if done right. Many owners opt for closed-deck block conversion at this point.

Estimated cost: $6,500-12,000

Typical onset: 80,000-150,000 mi

Symptoms: Oil seepage around head/block mating surface, Coolant weeping externally, Slight oil consumption increase, Burning oil smell after hard driving

Fix: Classic Subaru boxer issue — both heads need to come off. Expect 12-16 hours labor for head gasket replacement, includes resurfacing heads, new bolts, timing components while you're in there. Not an internal combustion failure like ringland, but still requires major disassembly.

Estimated cost: $2,500-4,000

Typical onset: 100,000-140,000 mi

Symptoms: Excessive smoke on boost, Loud turbo whine or grinding noise, Significant oil consumption, Loss of boost pressure, Metal shavings in intake or exhaust side

Fix: Turbo seal failure or bearing wear from heat cycles and oil starvation. Replacement turbo plus oil/coolant lines, 6-8 hours labor. OEM IHI units are scarce; most go aftermarket. Critical to address oil starvation issues (banjo bolt screens) before installing new turbo.

Estimated cost: $1,800-3,500

Symptoms: Rattling noise from timing cover, Sudden loss of power, Engine won't start after belt snap, Metal debris in timing cover area

Fix: Interference engine — if the belt snaps, you're looking at bent valves and potentially complete head work. Preventive replacement every 60k-70k miles is non-negotiable. Full timing service includes belt, tensioner, idlers, water pump, seals — 4-6 hours labor. If it breaks, add cylinder head R&R and valve work.

Estimated cost: $800-1,200 preventive; $4,000-7,000 if it fails

Typical onset: 70,000-120,000 mi

Symptoms: Grinds going into 2nd or 3rd gear, Difficulty downshifting under load, Crunching noise during spirited driving, Gear pop-out under deceleration

Fix: The 6-speed is strong but syncros wear from aggressive shifting and clutch dumps. Transmission needs to come out for rebuild — 10-14 hours labor plus internal parts. Many owners upgrade to brass syncros during rebuild. Half-measure fixes don't exist.

Estimated cost: $2,800-4,500

Symptoms: Turbo oil starvation leading to early failure, No obvious symptoms until turbo damage occurs, Low oil pressure under boost (if monitored)

Fix: Factory banjo bolts feeding the turbo have tiny mesh screens that clog with carbon and debris, starving the turbo of oil. This is a known design flaw. Remove screens or install aftermarket banjo bolts during any turbo service — 0.5 hours if caught during other work, but the damage is discovering it after turbo failure.

Estimated cost: $50-150 preventive; adds to turbo replacement cost if ignored

Typical onset: 50,000+ mi

Symptoms: Burns 1 quart per 1,000-2,000 miles, Blue smoke on startup, Low oil light between changes, Fouled spark plugs

Fix: EJ257s are known oil burners even without catastrophic ringland failure. Glazed rings or worn valve guides. Many owners live with it and check oil religiously. True fix requires full engine rebuild. Band-aid: higher-weight oil and frequent top-offs.

Estimated cost: $0 if managed; $6,500+ for proper fix