Subaru EJ20 Engine Problems And Reliability

The EJ20 engine is a 2.0-liter four-cylinder gasoline engine that first appeared in 1989 under the hood of the Subaru Legacy. This two-litre version laid the foundation for the history of the EJ series.

The EJ20 engine replaced the old 1.8-liter EA82 engine and became the main engine for many Subaru models for a long time. Like its predecessor, the EJ20 engine has an aluminum cylinder block with cast iron liners installed inside.

The most common version of the engine, the EJ20E , has aluminum alloy cylinder heads with SOHC (single overhead camshaft) design. The EJ20 head has four valves per cylinder and centrally located spark plugs.

ICE Features and Benefits

The diameter of the intake valves is 36 mm. The camshafts are driven by the crankshaft via a toothed belt. The belt needs to be replaced every 96560 km. The EJ20 was created in four phases of history.

Each generation has different power specifications – 125 hp, 135 hp, 155 hp. and the last – 140 hp. (5600 rpm) used in the Subaru Legacy BL. Naturally aspirated version with DOHC heads – EJ20D has 150 hp. at 6800 rpm.

When Subaru began manufacturing open platform block SOHC engines, they started using the EJ20N names. These engines also featured new SOHC cylinder heads, lightweight pistons, and a low-rpm tuned intake manifold.

The EJ20 Engine was installed

  • Subaru Impreza (WRX/STI)
  • Subaru Forester
  • Subaru Legacy
  • Isuzu Aska
  • SAAB 9-2X

EJ20 Engine Specifications

Volume (cm3)1994
Power (hp)115-155
Torque165-195 Nm
Timing driveBelt
Environmental classEuro 2/3/4
Fuel typeAI92/AI95
ICE featuresSOHC
Supply systemInjector
hydraulic liftersYes (until 1994)
Cylinder blockAluminum H4
cylinder headaluminum 16v
Cylinder diameter92 mm.
Stroke75 mm.
Compression ratio9.5-10
Phase regulatorNo
Engine oil4 l. 5w30
Average resource300 000 km.

Problems and disadvantages of Subaru EJ20 engines

The motors of this series are not perfect and have a number of some problems, below we will see which ones.

  1. Knock EJ20. Very often there is a knock in the 4th cylinder. This is the hottest cylinder, it cools the worst and it is there that the piston begins to knock, first on the cold, then always. This problem is solved by overhauling the motor.
  2. Oil leaks. Most often, camshaft seals and valve cover gaskets leak (most often).
  3. Zhor oil. It’s a common thing for EJ20 turbos, the reason is the occurrence of piston rings. Change the oil in time (every 7500 km) and do not skimp on it.

To maximize the resource for both the atmosphere and the EJ20 turbo, you need to pour exclusively original engine oil every 7500 km, use only high-quality 95-98 gasoline, calmly drive for bread and then there will most likely be no problems.

Naturally, WRX and STI are bought for other purposes, therefore, their engines may require overhaul even before the 100 thousand km mark. The resource of the atmospheric EJ20 engine is often much higher and can reach up to 250 thousand km or more.

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