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Home >> Subaru >> 2019 >> WRX STI Limited >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 13 (Engine Mechanical System (Except For STI)) >> Cylinder Head >> Inspection >> Valve Spring

Valve Spring

WARNING: This page is about a different variant/trim than selected.
  1. Check the valve spring for damage and deformation.
  2. Using a caliper gauge, valve spring tester, surface plate and try square, check the valve spring free length (reference), tension/spring height and squareness. If it is not within the standard, replace the valve spring.
    NOTE:
    • Measurement should be performed at a temperature of 20°C (68°F).
    • The free length of the valve spring is described as a reference. There is no need to replace the valve spring if the free length of the valve spring alone is out of standard.
    • To check the squareness of the valve spring, stand the valve spring on a surface plate and check its deflection at the top of the valve spring using a try square.
    G08317135Courtesy of SUBARU OF AMERICA, INC.

    Valve spring free length (reference): 

    CVT model 

    Standard 

    41.68 mm (1.6409 in)

    MT model 

    Standard 

    41.06 mm (1.6165 in)

    Valve spring tension/spring height: 

    CVT model

    Set

    Standard 

    182 - 210 N (18.56 - 21.41 kgf, 40.92 - 47.22 lbf)/33.0 mm (1.2992 in)

    Lift

    Standard 

    502 - 554 N (51.19 - 56.49 kgf, 112.87 - 124.56 lbf)/22.0 mm (0.8661 in)

    MT model

    Set

    Standard 

    182 - 210 N (18.56 - 21.41 kgf, 40.92 - 47.22 lbf)/33.0 mm (1.2992 in)

    Lift

    Standard 

    552 - 610 N (56.29 - 62.20 kgf, 124.11 - 137.15 lbf)/22.0 mm (0.8661 in)

    Valve spring squareness: 

    Standard 

    2.5°, 1.8 mm (0.0709 in) or less