Valve Spring

Check the valve spring for damage and deformation.
Using a caliper gauge, valve spring tester, surface plate and try square, check the valve spring free length, 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).
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.

Fig 1: Checking Valve Spring Free Length

Courtesy of SUBARU OF AMERICA, INC.

Valve spring free length:

Standard

44.03 mm (1.733 in)

Valve spring tension/spring height:

Set

Standard

182 - 210 N (18.56-21.41 kgf, 40.92-47.22 lbf)/33.0 mm (1.299 in)

Lift

Standard

440 - 486 N (44.87-49.56 kgf, 98.93-109.27 lbf)/22.0 mm (0.866 in)

Valve spring squareness:

Standard

2.5°, 1.9 mm (0.075 in) or less