Cylinder Head - Flatness Specification
File in Section: 6 - EngineBulletin No.: 57-61-37
Date: December, 1995
Subject:
Section 6A - Engine Mechanical - Cylinder Head Flatness Specification for 2.0L, 2.2L Engines (VINs 1, G, 4 - RPOs LL8, LM3, LN2)
Models:
1987-89 Buick Skyhawk
1993-96 Buick Century
1987 Cadillac Cimarron
1987-96 Chevrolet Beretta, Corsica, Cavalier
1987-88 Oldsmobile Firenza
1993-96 Oldsmobile Cutlass Ciera
1987-93 Pontiac Tempest (GM of Canada Only)
1995-96 Pontiac Sunfire
1994-96 Chevrolet and GMC Truck S Models with 2.0L, 2.2L Engines (VINs 1, G, 4 - RPOs LL8, LM3, LN2)
The cylinder head flatness specification was omitted in some of the service manuals for the above vehicles.
Cylinder Head Flatness Specification
The cylinder head can be reused if the cylinder head warpage is less than 0.05 mm (0.002 in.) within any 152 mm (6.0 in.) area of the cylinder head sealing surface or 0.1 mm (0.004 in.) over the entire length of the cylinder head.
Resurface the cylinder head if warpage is over 0.05 mm (0.002 in.) within any 152 mm (6.0 in.) area, or more than 0.1 mm (0.004 in.) and less than 0.25 mm (0.010 in.) over the entire length of the cylinder head. The cylinder head must be replaced if warpage is over 0.25 mm (0.010 in.).