Subaru EJ20 Engine Service and Repair Manuals

Subaru EJ20 (H4) Engine Workshop Manual is a detailed repair, maintenance and diagnostic guide for the EJ20 engine used in Subaru Impreza, Legacy, Forester and other models.

📌 What the manual includes:

🔧 Complete engine disassembly and assembly.

⚙️ Timing adjustment (belt, AVCS valve timing).

💨 Turbocharger maintenance (EJ20G, EJ205, EJ207 versions).

⚡ Electrical diagrams and sensor diagnostics.

🛠 Part specifications, tightening torques, valve clearances.

Ideal for Subaru owners and engine repair specialists! 🚗🔧

• Subaru All Engine>>

📌 Cars with EJ20 Engine:

🔹 Subaru Legacy

1st generation (1989–1994) – EJ20E (naturally aspirated), EJ20G (turbo)

2nd generation (1993–1999) – EJ20E, EJ20D (DOHC), EJ20G (turbo)

3rd generation (1998–2003) – EJ201, EJ202, EJ204 (naturally aspirated), EJ206, EJ208 (turbo)

4th generation (2003–2009) – EJ204 (DOHC), EJ206, EJ208 (turbo)

🔹 Subaru Impreza

1st generation GC, GF (1992–2000) – EJ20E, EJ20D (naturally aspirated), EJ20G, EJ20K (turbo)

2nd generation GD, GG (2000–2007) – EJ201, EJ202, EJ204 (naturally aspirated), EJ205, EJ207 (turbo, WRX/STI)

3rd generation GH, GE, GR, GV (2007–2014) – EJ204 (naturally aspirated), EJ205, EJ207 (turbo, WRX/STI)

4th generation GP, GJ (2011–2016, only WRX STI in Japan) – EJ207

🔹 Subaru Forester

SF (1997–2002) – EJ20E, EJ20G, EJ205 (turbo)

SG (2002–2008) – EJ202, EJ204 (naturally aspirated), EJ205, EJ207 (turbo)

SH (2008–2013, in Japan) – EJ204, EJ205

SJ (2013–2018, in Japan) – EJ204

🔹 Subaru Outback

1st generation (1994–1999, Legacy Outback in Japan) – EJ20D

2nd generation (1999–2003) – EJ201, EJ202

3rd generation (2003–2009) – EJ204

🔹 Subaru WRX and WRX STI

All generations of WRX STI (1994–2020, JDM version) – EJ207 (best turbo EJ20, forged bottom, up to 400+ hp when modified).

🔹 Subaru Exiga

2008–2018 – EJ204, EJ205

🔹 Subaru Levorg

1st generation (2014–2020, JDM only) – EJ20DIT (turbo)

🚗 EJ20 engine types

✅ EJ20E/EJ201/EJ202 – naturally aspirated SOHC, the most reliable.

✅ EJ20D/EJ204 – naturally aspirated DOHC, a bit more capricious due to phase shifters.

✅ EJ20G/EJ20K – early turbocharged versions for Legacy, Impreza WRX.

✅ EJ205/EJ207 – turbo versions for WRX and STI, EJ207 is one of the best Subaru engines.

✅ EJ206/EJ208 – turbo with a two-shaft system (Twin-Scroll Turbo).

✅ EJ20Y/EJ20X (EJ20DIT) – new turbo engines with direct injection.

1. Cylinder head gasket 🔥

✅ What to look for:

Engine overheating.

White smoke from the exhaust pipe.

Oil in the coolant expansion tank.

Bubbles in the antifreeze.

📌 Solution: Replace the cylinder head gaskets with reinforced versions (for example, multilayer metal ones from EJ207).

2. Oil consumption (oil burner) 🛢

✅ What to look for:

A decrease in the oil level without visible leaks.

Soot on the spark plugs.

Bluish smoke from the exhaust.

📌 Solution: Use high-quality oil (5W-40, 10W-60 for turbo). Check the condition of the piston rings and valve stem seals.

3. Bearing rotation ⚠️

✅ What to look for:

Knocking in the lower part of the engine (especially when cold).

Metal particles in the oil.

Drop in oil pressure.

📌 Solution: Timely oil change (every 5-7 thousand km in turbo versions). Use high-quality oil and avoid overheating.

4. Turbine failure (for turbo versions EJ20G, EJ205, EJ207) 🌀

✅ What to look for:

Loss of thrust, delayed turbine response.

Whistling or howling during acceleration.

Oil leakage through the turbine seals.

📌 Solution: Monitor the oil condition, replace it regularly. Check the condition of the intercooler and intake system.

5. Timing belt wear ⏳

✅ What to pay attention to:

The engine starts with difficulty, unstable operation.

Extraneous sounds from the timing belt area.

Mileage over 100,000 km without replacing the belt.

📌 Solution: Replace the timing belt and rollers every 90,000 - 100,000 km. When the belt breaks, the valves bend!