Deck Flatness Inspection

WARNING: This page is about a different car, the 2007 Suzuki XL7. However, it is still accessible from the selected car via links, so may be relevant.

Fig 1: Checking Deck Flatness

Courtesy of SUZUKI OF AMERICA CORP.

Ensure the engine block decks are clean and free of gasket material.
Inspect the surface for any imperfections or scratches that could inhibit proper cylinder head gasket sealing.
Place a straight-edge diagonally across the cylinder block deck face surface.
Measure the clearance between the straight-edge and the cylinder block deck face using a feeler gauge at 4 points along the straight-edge.
If the warpage is less than 0.05 mm (0.002 in), the cylinder block deck surface does not require resurfacing.
If the warpage is between 0.05-0.20 mm (0.002-0.008 in) or any imperfections or scratches that could inhibit proper cylinder head gasket sealing are present, the cylinder block deck surface requires resurfacing.
If resurfacing is required the maximum amount that can be removed is 0.25 mm (0.010 in).
If the cylinder block deck surface requires more than 0.25 mm (0.010 in) material removal the block must be replaced.

Reference: ENGINE BLOCK ASSEMBLE .