2005 Subaru Legacy Problems: 1 Issues Every Owner Should Know
2005 model year · 3,800+ owner reports · Updated April 2026
According to Au7o's analysis of 3,800+ owner reports, the 2005 Subaru Legacy has 1 documented known issues, with 1 rated critical. The most serious is EJ25 Head Gasket Failure ($1,600-$3,000 repair). The most commonly reported issue is EJ25 Head Gasket Failure with 3,800 owner reports. Across all issues, repair costs range from $1,600 to $3,000. DIY maintenance guides at au7o.io.
All 1 Known Issues
On the 2000-2009 Subaru Legacy EJ25, the 2.5L EJ25 engine in 2000-2009 Legacys suffers from the same head gasket failure that plagues all EJ25-equipped Subarus. The composite gaskets degrade, causing external oil and coolant leaks at the head-to-block mating surfaces. The Legacy's higher-mileage highway use means many owners encounter this between 80,000-150,000 miles. Phase 1 engines (2000-2005, single overhead cam) are more prone to coolant leaks, while Phase 2 engines (2006-2009, DOHC) tend to leak oil externally first.
Common Symptoms
- External oil seepage at bottom of cylinder heads
- Coolant level gradually decreasing
- Oil and coolant mixing (milky residue on oil cap)
- Overheating at highway speeds
- Sweet smell from engine compartment
- White exhaust smoke in severe cases
How to Fix
Replace both head gaskets with updated MLS (multi-layer steel) gaskets. Use Six Star MLS gasket kit or Subaru OEM MLS (11044AA633 for SOHC, 11044AA770 for DOHC). Machine heads to 0.002-inch flatness. Replace timing belt, tensioner, idlers, water pump, thermostat, and valve cover gaskets while apart. Use Subaru Cooling System Conditioner (SOA635071). Total job is 10-14 hours labor.
What Owners Are Using
Parts and tips from 3,800+ owners who fixed this issue
- Tip
- Tip
- UpgradeComplete timing belt kit with water pump for a comprehensive replacement (Gates Timing Belt Kit with Water Pump)
- UpgradeHigh-quality engine oil is critical after timing service (Castrol Edge Full Synthetic Motor Oil)