Head Gasket & Engine
The most common major repair on EJ-engine Subarus. We've done hundreds of them — correctly, with in-house head resurfacing and updated gasket specs that last.
The EJ25 Head Gasket Issue
If you own a Subaru with a 2.5L naturally aspirated EJ25 engine — Outback, Legacy, Forester, or Impreza from roughly 1996 through 2011 — head gasket failure is not a question of if. It's a question of when, and whether you catch it before it causes additional damage.
Phase 2 Failure (Most Common)
Internal combustion leak into the cooling system. Symptoms: gradual coolant loss with no visible external leak, white exhaust smoke (especially cold start), sweet smell from exhaust, bubbles in the coolant reservoir. Engine temperature may remain normal until the leak worsens.
Phase 1 Failure (Older EJ25s)
External coolant seep between the head and block at the gasket edge. Visible as residue or discoloration at the cylinder head seam. Less immediately dangerous but progressive — it will worsen, and the coolant loss adds up.
Not sure which engine you have? Call us at (530) 823-7645 or send us your VIN — we'll tell you your engine and what to watch for in under a minute.
Every Component That's
Exposed Gets Addressed
A head gasket replacement on a Subaru EJ engine is a major disassembly — both cylinder heads come off, the cooling system is completely drained, and the engine is essentially half apart. Everything exposed during that process is inspected and serviced. Doing anything less means leaving known-age components in place that you'll pay full labor to reach again in short order.
- Head gaskets — updated MLS (multi-layer steel) spec or OEM, both sides
- Cylinder head resurfacing — machined in-house for proper flatness and sealing surface
- Head bolts — replaced with new (stretch bolts are single-use)
- Valve cover gaskets — replaced while the heads are already removed
- Water pump — replaced while the cooling system is open
- Thermostat — replaced as a matter of course
- Coolant flush — full system refill with Subaru-spec Long Life Coolant
- Timing belt — evaluated and replaced if at or approaching interval
- Intake and exhaust manifold gaskets — inspected and replaced as needed
- Complete multi-point inspection on completion
Why the complete job matters
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Head flatness determines gasket life
Overheating warps aluminum cylinder heads. Installing a new gasket against a warped head surface guarantees early failure. We measure and resurface both heads in-house — that's not optional, it's what makes the repair last.
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Head bolts are one-time use
EJ head bolts are torque-to-yield fasteners — they stretch during installation and cannot be reused reliably. Reusing them risks undertorque, uneven clamping, and a blown gasket well before its time. We replace them every time, no exceptions.
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Timing belt access is included in the labor
Head gasket work on an EJ engine requires removing the timing belt. If your belt is within 20,000 miles of its interval, replacing it now is essentially free labor. We'll tell you where yours stands and let you decide — but we won't reassemble an engine with a belt that's due in six months without saying something.
We've Done This Repair
More Times Than We Can Count
In-House Machine Shop
Cylinder head resurfacing happens here, not at an outside machine shop with a multi-day wait and a markup you can't see. We measure the head, machine the surface flat, and verify it before reassembly. This isn't a value-add — it's a requirement for a head gasket repair that actually holds. Shops that outsource this are adding uncertainty and delay to a job that demands precision.
EJ-Specific Experience
Our technicians have performed this repair on hundreds of EJ25 engines across every application — Forester, Outback, Legacy, Impreza. We know the EJ's specific torque sequences, the updated gasket specifications that outlast original equipment, the secondary items that reveal themselves once the heads are off, and the cooling system quirks that need attention to prevent a repeat failure.
2-Year Warranty
The complete head gasket repair — gaskets, head bolts, machine work, water pump, thermostat, and all associated labor — is covered by our 2-year warranty. A head gasket repair is a significant investment. We stand fully behind it because we do the job correctly the first time, with the right parts and the right process.
Head Gasket FAQ
How do I know if my Subaru has a head gasket problem?
The most reliable early indicator on EJ25 engines is slow coolant loss with no visible external leak — you're adding coolant but can't find where it's going. White or sweet-smelling exhaust smoke, especially on a cold start, is a stronger sign. A combustion leak test (also called a block test or CO test) checks for exhaust gases in the coolant — it's a definitive, non-invasive confirmation. If you're topping off your coolant more than once between oil changes, don't wait. Catching this before the engine overheats is the difference between a head gasket job and an engine rebuild.
Can I keep driving with a leaking head gasket?
Short answer: no, not without significant risk. A Phase 2 internal leak slowly depletes your coolant, which means the engine is approaching an overheating event without warning. Subarus can go from normal temperature to serious overheat quickly once coolant loss reaches a critical level — and a single overheating episode can warp the heads, significantly increasing the repair scope and cost. If you've been diagnosed or strongly suspect a head gasket leak, schedule service and monitor your coolant level closely in the meantime.
What about head gasket sealers and "liquid gasket" products?
These products can temporarily reduce symptoms on a minor external seep — but they don't fix the gasket, they don't address the underlying cause, and they can foul cooling system components in ways that complicate the eventual repair. On an internal combustion leak, they're generally ineffective. We've seen engines come in where sealant residue had partially clogged the radiator, water pump passages, or heater core — adding scope and cost to the job. If your Subaru has a head gasket problem, it needs a head gasket repair.
How much does a Subaru head gasket repair cost?
A complete head gasket repair covers both heads, resurfacing, all associated gaskets and seals, water pump, thermostat, and coolant flush. Pricing depends on the model year, engine variant, and condition of the heads when we get in there. If the timing belt is due, adding it at the same time costs only the parts since the labor is already included in the disassembly. We provide a firm written estimate after inspection, before any work is authorized.
How long does a head gasket repair take?
Plan on 3–5 days. The disassembly, head machining, parts acquisition, reassembly, and thorough coolant system bleeding take time when done correctly. We don't rush head gasket work — the reassembly sequence and torque procedure on EJ heads is exacting, and the cooling system needs to be fully purged of air before the car goes back on the road. Loaner vehicles are available for the duration; just mention it when you call or schedule.