Home Subaru EJ20 2.0L Engine

Subaru EJ20 2.0L Engine Specs, Problems & Reliability

The Subaru EJ20 is a 2.0-liter four-cylinder, gasoline boxer engine that firstly appeared in 1989 under the hood of Subaru Legacy. This two-liter version laid down the history of the EJ series. The EJ20 replaced the old EA82 1.8-liter engine and became the primary engine option for many Subaru models for a long time.

Like the predecessor, the EJ20 engine has an aluminum cylinder block with dry cast iron sleeves/liners installed inside. The most common version of the naturally aspirated engine, the EJ20E, has aluminum alloy cylinder heads with SOHC design (single overhead camshaft). EJ20 head features four valves per cylinder and centrally located spark plugs. The diameter of the intake valves is 36 mm, and of the exhaust valves - 32 mm. The camshafts are driven by the crankshaft via a timing belt. The timing belt requires changing every 60,000 miles. The EJ20E was produced in four history steps. Each generation has different power specs - 125hp, 135hp, 155hp and the last - 140 hp (at 5,600 rpm) engine used in Subaru Legacy BL. The naturally aspirated version with DOHC heads is EJ20D. This engine produces 150hp at 6,800rpm.

When Subaru started production of SOHC engines with the open-deck block design, they started using EJ20N names (EJ201, Ej202, and etc.). These engines also had new SOHC cylinder heads, lightweight pistons, and an intake manifold tuned at low RPMs. The power of the EJ201 engine is the same 125 hp at 5,600rpm. But the EJ202 is a more powerful version due to a light cylinder block, 4-2-1 exhaust headers, and another intake manifold. It produced 138 hp at 5,600rpm and 138 lb-ft (187 Nm) at 4,400rpm.

The EJ203 engine is characterized by the presence of MAF-sensor and an electronic throttle body. The EJ204 engine features double overhead camshafts and variable valve timing on the intake side (AVCS). The power of EJ204 is 155 hp (190 hp - high compression version).

The EJ series also includes other displacement versions - EJ15, EJ16, EJ18, EJ22, and EJ25. The 2.0L EJ20 was replaced by the new naturally-aspirated version in the Subaru FB engine family - the FB20 engine.

Engine Specs

Gunma Oizumi Plant
Production years
1989-present day
Cylinder block material
Cylinder head material
Fuel type
Fuel system
Fuel injection
Flat-4 (opposed)
Number of cylinders
Valves per cylinder
Valvetrain layout
Bore, mm
Stroke, mm
Displacement, cc
Type of internal combustion engine
Four-stroke, naturally aspirated and turbocharged versions
Compression Ratio
9.5 (EJ20X/EJ20Y)
9.7 (EJ20J)
10.0 (EJ204 Impreza II)
10.1 (EJ201/EJ202/EJ20D)
10.2 (EJ204 Impreza III)
Power, hp
125/5500 (EJ20E first version)
Torque, lb ft
127 lb-ft (172 Nm)/4,200 (EJ20E first version)
Engine weight
308 lbs (140 kg)
Firing order
Engine oil weight
0W-30, 5W-30, 5W-40, 10W-30, 10W-40
Engine oil capacity, liter
4.0 (1993-2007) and 4.2 (2007+)
Oil change interval, mile
Subaru Forester, Subaru Legacy, Subaru Impreza, Isuzu Aska, SAAB 9-2X

EJ20 Problems and Reliability

1. Knocking noise from EJ20 Engine. The engine has a problem in the 4th cylinder. This cylinder is hottest; the cooling is worse in this place of the engine. In this case, the piston or rod starts knocking then the engine is cold at first and all time after some period. That requires an engine rebuild.
2. Oil leaks. Most often, the oil leaks out of camshaft oil seals and gaskets of cylinder head covers.
Engine life of naturally aspirated EJ20 is around 150,000 miles (250,000 km) with proper maintenance.