Oil leaks and broken cylinder head bolts may occur if the head bolts are not properly tightened. The newest level of cylinder head gasket and cylinder head bolts are recommended any time cylinder head service is performed. The new cylinder head gasket and bolts require a different service procedure for all 1992 and earlier 2.3L engines. If cylinder head service is required, refer to the following procedures for cylinder head gasket replacement and cylinder head bolt “Torque Plus Angle” steps to provide more uniform sealing.
The new head gasket and bolts are uniquely different from the production designed parts. Because of the difference, the new cylinder head bolts are the only bolts that can be used with the new head gasket. If a previous head gasket is to be used, or if head bolts are not available for the new gasket, the previous head gasket and bolts must be used. Failure to properly torque the cylinder head gasket can lead to an improper sealing surface, which can result in a leaking condition and broken head bolts.
With the cylinder block and head properly prepared, install the new head gasket. The camshaft must be properly positioned to ensure proper timing alignment.
Install all 10 head bolts into the block, finger tight.
Use the new “Torque Plus Angle” procedure as follows only for new head gasket and bolts.
Tighten all 10 cylinder head bolts in sequence shown in service manual to 51 ft.lbs. (70 Nm).
Retighten all 10 head bolts in sequence to 51 ft.lbs. (70 Nm).
Tighten all 10 head bolts in sequence an additional 90-100°.
Courtesy of ENGINE BUILDER TECH SOLUTIONS GUIDE.