Skylark L4-138 2.3L DOHC VIN D MFI (1988)
10.
Replace the oil flow check valve (see Figure 5) in 1988 through 1989 model year vehicles. Refer to the applicable 1991 model year service
manual. The check valve does not need to be replaced in 1990 or newer vehicles or those vehicles where the check valve has been previously
replaced.
IMPORTANT:
To determine if the check valve has been previously replaced on 1988 through 1989 vehicles, shine a flashlight into the oil check valve. If there
are three dimples immediately above the check ball, it is the new style oil flow valve and should not be replaced (figure 5).
11.
Apply clean engine oil SPARINGLY to the threads and the bottom side of the flange of the bolt (Figure 6).
NOTICE:
THE TIGHTENING PROCEDURE MUST BE USED TO ASSURE GASKET LIFE. FAILURE TO FOLLOW THIS PROCEDURE EXACTLY
MAY RESULT IN CYLINDER HEAD GASKET LEAKAGE.
