Cylinder Head Assembly: Service and Repair

Fig. 61 Exhaust Manifold Bolt Loosening Sequence. 1989 300ZX:

Fig. 62 Exhaust Manifold Bolt Loosening Sequence Maxima:

DISASSEMBLY
1. Remove exhaust manifolds, then the rocker shafts with rocker arms. Loosen exhaust manifold attaching bolts in sequence, Figs. 61 and 62, in 2 or 3 steps.

Fig. 64 Cylinder Head Exploded View. Except 1990-92 300ZX & 1992 Maxima w/VE30DE Engine:

Fig. 65 Securing Valve Lifters To Valve Guide.:

2. Remove hydraulic valve lifters and lifter guide, Fig. 64, noting the following:
a. Secure lifters with safety wire to prevent them from falling out of guide, Fig. 65.
b. Do not invert lifters to prevent air from entering them.
c. Valve lifters are serviced as an assembly only and must not be disassembled.
d. Mark lifters so they may be reinstalled in their original positions.
3. Remove camshaft and camshaft oil seal.
4. Remove valves and valve components using a suitable valve spring compressor.

Fig. 70 Exhaust Manifold Bolt Tightening Sequence.:

Fig. 71 Exhaust Manifold Bolt Tightening Sequence.:

ASSEMBLY
1. Install valves and valve components. Install outer valve springs with narrow pitch side towards cylinder head.
2. Install camshaft, then the camshaft oil seal. Apply clean engine oil to seal prior to installation.
3. Install hydraulic valve lifters and lifter guide.
4. Install rocker shaft assemblies, then the exhaust manifolds. Tighten manifold attaching bolts to specifications in sequence, Figs. 70 and 71.