Head gasket problems have been associated with Subaru boxer engines historically, though newer designs have improved significantly. If you suspect head gasket issues in your 2019 Outback, knowing the symptoms helps you catch problems early before catastrophic engine damage occurs.
Why Boxer Engines Have Had Issues
The horizontally-opposed boxer engine layout places head gaskets at the lowest point of each cylinder head. While this design has many benefits, it historically allowed coolant to seep past gaskets more easily than in vertical engine designs. Subaru has addressed this in modern engines.
2019 Outback Engine Context
The 2019 Outback uses the FB25 2.5L engine or optional FA24 2.4L turbo. These newer designs with multi-layer steel gaskets have significantly better head gasket reliability than earlier EJ-series engines.
Head Gasket Leak Symptoms
- External coolant leak - Wet areas around head/block junction
- Coolant loss without visible leak - Level drops, no puddles
- White exhaust smoke - Coolant burning in combustion
- Milky oil - Coolant mixing with oil
- Overheating - Compromised cooling system
- Bubbles in coolant - Combustion gases entering cooling system
- Sweet smell from exhaust - Coolant being burned
Testing for Head Gasket Failure
- Visual inspection - Look for wetness around head gasket area
- Cooling system pressure test - System won't hold pressure
- Block test - Detects combustion gases in coolant
- Oil check - Look for milky appearance
- Compression test - Check for pressure leaking between cylinders
Repair Costs
- Diagnosis: $100-$200
- Head gasket replacement (one side): $1,000-$2,000
- Both head gaskets: $1,500-$3,000
- With machine shop work: $2,000-$4,000
Prevention
- Maintain proper coolant mixture and level
- Don't overheat the engine
- Use Subaru-approved coolant
- Address cooling system issues promptly