Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2021 Subaru WRX BaseFACTORY OEM SERVICE PROCEDURE
Section 13 (Engine Lubrication System (2.5L)): General Description: Specification
WARNING: This page is about a different variant/trim than selected.
| Lubrication method | Forced lubrication | |||
| Oil pump | Pump type | Trochoid type | ||
| Number of teeth | Inner rotor | 9 | ||
| Outer rotor | 10 | |||
| Outer rotor diameter x Thickness mm (in) | 78 x 11 (3.07 x 0.43) | |||
| Tip clearance between inner and outer rotors mm (in) | Standard | 0.04 - 0.14 (0.0016 - 0.0055) | ||
| Case clearance between outer rotor and pump case mm (in) | Standard | 0.10 - 0.175 (0.0039 - 0.0069) | ||
| Side clearance between inner rotor and pump case mm (in) | Standard | 0.02 - 0.07 (0.0008 - 0.0028) | ||
| Relief valve spring | Free length mm (in) | 73.7 (2.902) | ||
| Installed length mm (in) | 54.7 (2.154) | |||
| Load when installed N (kgf, lbf) | 93.1 (9.49, 20.93) | |||
| Performance (Oil temperature 80°C (176°F)) | 600 r/min | Discharge pressure kPa (kg/cm2 , psi) | 98 (1.0, 14) | |
| Discharge rate L (US qt, Imp qt)/min | 6.4 (6.8, 5.6) or more | |||
| 6, 000 r/min | Discharge pressure kPa (kg/cm2 , psi) | 392 (4.0, 56.8) | ||
| Discharge rate L (US qt, Imp qt)/min | 63.0 (66.6, 55.4) or more | |||
| Relief valve working pressure kPa (kg/cm2 , psi) | 538 (5.5, 78) | |||
| Oil filter | Filter type | Full-flow filter type | ||
| Filtration area cm2 (sq in) | Outer diameter: 68 mm (2.68 in) (black) | 800 (124) | ||
| Outer diameter: 67.4 mm (2.65 in) (blue) | 555 (86) | |||
| By-pass valve opening pressure kPa (kg/cm2 , psi) | 160 (1.63, 23.2) | |||
| Outer diameter x Width mm (in) | Outer diameter: 68 mm (2.68 in) (black) | 68 x 65 (2.68 x 2.56) | ||
| Outer diameter: 67.4 mm (2.65 in) (blue) | 67.4 x 65.3 (2.65 x 2.57) | |||
| Installation screw specifications | M 20 x 1.5 | |||
| Oil pressure switch | Type | Immersed contact point type 7 | ||
| Operating voltage - power consumption | 12 V - 3.4 W or less | |||
| Warning light operating pressure kPa (kg/cm2 , psi) | 14.7 (0.15, 2.1) | |||
| Proof pressure kPa (kg/cm2 , psi) | 981 (10, 142) or more | |||
| Engine oil | Total capacity (at overhaul) L (US qt, Imp qt) | 5.0 (5.3, 4.4) | ||
| When replacing engine oil and oil filter L (US qt, Imp qt) | 4.3 (4.5, 3.8) | |||
| When replacing engine oil only L (US qt, Imp qt) | 4.0 (4.2, 3.5) | |||
Specified oil:
CAUTION:
- Use 5W-30 (synthetic oil).
- It is acceptable to fill an engine with oil of another brand when replacing the oil, but make sure to use the following engine oil specified by Subaru.
| Engine oil standard | SAE viscosity No. |
|---|---|
|
Those with SN or SN PLUS "Resource Conserving" logo in case of API standard. or Those with GF-5 "starburst mark" displayed on top of the container in case of ILSAC standard. |
5W-30 (synthetic oil) |
NOTE:
The proper viscosity oil helps the engine maintain its ideal temperature, and cranking speed increased by reducing viscosity friction in hot condition.
Factory Service Tools
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.