Head gasket problems have been part of Subaru's history, though newer engines have improved significantly. If you're concerned about your 2019 Impreza, knowing the warning signs helps you catch problems early—before catastrophic damage occurs.
The FB20 Engine
The 2019 Impreza uses the FB20 2.0L boxer engine with improved multi-layer steel head gaskets. These are more reliable than earlier designs, but no gasket lasts forever.
Head Gasket Functions
The head gasket seals three separate systems:
- Combustion chambers (compression seal)
- Coolant passages (prevents coolant loss)
- Oil passages (keeps oil separated)
Warning Signs
- External coolant leak - Wet spots 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 engine oil
- Overheating - Compromised cooling passages
- Bubbles in coolant - Combustion gases in cooling system
- Oily coolant - Oil entering cooling system
Testing Methods
- Visual inspection - Look for seepage at head gasket area
- Pressure test - System won't hold pressure if leaking
- Block test - Detects combustion gases in coolant
- Oil analysis - Check for coolant contamination
- Compression test - Reveals pressure leaks between cylinders
If You Suspect Problems
- Monitor coolant level weekly
- Check oil for milky appearance
- Watch temperature gauge carefully
- Have cooling system pressure tested
- Don't ignore any warning signs
Repair Costs
- Diagnosis: $100-$200
- Head gasket (one side): $1,000-$2,000
- Both head gaskets: $1,500-$3,000
- With machine work: $2,000-$4,000