Spring Squareness
WARNING: This page is about a different car, the 2007 Suzuki SX4. However, it is still accessible from the selected car via links, so may be relevant.
Use a square and surface plate to check each spring for squareness in terms of clearance between end of valve spring and square. Valve springs found to exhibit a larger clearance than limit must be replaced.
Valve spring squareness
Limit: 2.2 mm (0.087 in.)