If you own a 2000-2011 Subaru with the 2.5L EJ25, you've probably heard the warnings. The Phase II EJ25's open-deck design and single-layer gasket lead to an external coolant leak between the block and head - almost an expected service item between 100,000 and 150,000 miles. Here's exactly what fails, what it costs, and what to ask about before you buy.
On the Phase II EJ25, head gasket leaks are the rule, not the exception, between 100K and 150K miles. Most fail externally (coolant seep) rather than internally, which buys time but doesn't fix the problem.
Coolant weeps from the seam between the block and head, often dripping onto the exhaust on bank 2. Smells sweet, leaves a brown crust. Almost universal between 100K-150K on Phase II EJ25.
View P0128 Diagnosis →Subaru settled a class action over EJ25 head gaskets and extended the warranty to 8 years or 100,000 miles on affected vehicles, plus offered a coolant additive program.
Get help with my Subaru →A small percentage fail internally, mixing coolant and oil. Look for milky oil, white smoke, or coolant disappearing without an external leak. Much more expensive to fix.
View P0128 Diagnosis →EJ25 timing belt service is due at 105K. Smart owners do it during the head gasket job because labor overlaps heavily.
Run free diagnosis →Common Subaru high-mileage seep onto the exhaust. Often done together with the head gasket job or timing belt service.
Run free diagnosis →The O-rings on the coolant crossover behind the intake harden and seep. Often misdiagnosed as a head gasket because the leak path looks similar.
Run free diagnosis →Run a free AI diagnosis tailored to your exact Subaru EJ25. Get the most likely cause and repair estimate in under 30 seconds.
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2000-2009 Phase II EJ25 (Outback, Forester, Legacy, Impreza naturally aspirated) without documented head gasket replacement. Phase I (1996-1999) is actually less affected externally but has its own oil leak quirks.
Any 2000-2009 EJ25 that already had its head gaskets replaced with the updated multi-layer steel gaskets, or 2010+ models that moved to the FB25 (which has its own problem - oil consumption).
Plan on $1,800-$3,500 for a head gasket job at an independent Subaru shop. Bundle the timing belt, water pump, valve cover gaskets, and oil pump reseal - you're already in there. Total bundled service typically runs $2,500-$3,800.
If your Subaru EJ25 is throwing a check engine light, these codes are most associated with the problems above. Click any code for full diagnosis steps and typical repair costs.
The Phase II EJ25 uses an open-deck block with a single-layer gasket. Heat cycles cause the block face to flex against the head, and the gasket loses its seal at the outside edge. Subaru updated to a multi-layer steel gasket as the field fix.
$1,800-$3,500 at an independent Subaru specialist. Bundling the timing belt, water pump, and valve cover gaskets is standard practice and usually adds only $400-$800.
Yes. Subaru settled a class action in 2014 covering many 1999-2009 vehicles with the EJ25. The settlement extended the head gasket warranty to 8 years or 100,000 miles and provided a free coolant conditioner program.
2000-2009 Outback, Forester, Legacy, and Impreza with the naturally aspirated 2.5L EJ25 (Phase II) are the most affected. Turbo EJ255/EJ257 fail differently and less often.
Coolant additive (the Subaru "conditioner" sold during the class action) sometimes slows an external seep. It is not a long-term fix and will not save an internally failed gasket.