← Subaru WRX (GD/GG, 2002-2007) problems
Head gasket leaks and head lifting on the 2.5L turbo (2006-07)
Q: What causes "Head gasket leaks and head lifting on the 2.5L turbo (2006-07)" on the Subaru WRX (GD/GG, 2002-2007), and how is it fixed?
A: A repair-trade magazine says most EJ25 head gasket failures show up around 100k miles as slow leaks, and that detonation (more likely with more boost) can also kill turbo EJ25 gaskets. Fix: Rule out simpler causes first: valve cover gaskets (see the EJ255 valve cover entry), air in the cooling system, a bad overflow hose or cap.
Symptoms
Slow oil or coolant seepage along the seam where each cylinder head meets the block, coolant loss or overheating, boost that wanders, or a sweet coolant smell and white smoke on cold start.
Cause
A repair-trade magazine says most EJ25 head gasket failures show up around 100k miles as slow leaks, and that detonation (more likely with more boost) can also kill turbo EJ25 gaskets. Owners and mechanics report the turbo 2.5L engines suffer this less often than the non-turbo EJ25s that made it famous; tuning shops on a 2006 forum thread blame warped heads, out-of-round cylinders or heads lifting under high cylinder pressure on modified cars. Sources are mixed and mostly anecdotal, so treat it as a risk to check, not a certainty.
Fix (summary)
Rule out simpler causes first: valve cover gaskets (see the EJ255 valve cover entry), air in the cooling system, a bad overflow hose or cap. A shop can confirm with a cooling-system pressure test and a combustion (block) test. The proper repair is new head gaskets with the heads checked for flatness and resurfaced, new head bolts, and usually the timing belt, water pump and idlers at the same time. Keep the tune conservative to avoid detonation.
Other GD problems
- Cracked piston ring lands from detonation
- Rod-bearing wear on the 2.0L EJ205
- Clogged oil-feed screens starving the turbo (P0011)
- Timing belt is an interference-engine risk; 105k mi / 105 months
- Stock transmission/clutch is the fuse under extra power
- Worn synchros (3rd gear) and cold-shift shudder
Sources
- Subaru EJ25 Head Gasket Problems — Underhood Service (trade magazine for repair shops, Apr 2025) (editorial; read 2026-10-22; full page read)
- Head-Lifting or Head Gasket Problems — NASIOC forum (replies from tuning shops, 2006) (forum thread; read 2026-10-22; search excerpt only)
- Are the head gasket issues on the 2.5 engines as bad as everyone says? — r/subaru (reddit; read 2026-10-22; search excerpt only)
Summaries are in our own words. Not repair instructions; consult the factory service manual.
Report a correction — spotted an error or have a better source? Email hello@chassisdex.com.