Cylinder Head Assembly: Service and Repair
REMOVAL - CYLINDER HEAD1. Perform fuel system pressure release procedure before attempting any repairs.
2. Disconnect battery negative cable.
3. Drain cooling system.
4. Remove air filter housing and inlet tube.
5. Remove intake manifold.
6. Remove heater tube support bracket from cylinder head.
7. Disconnect radiator upper and heater supply hoses from water outlet connections.
8. Remove accessory drive belts.
9. Raise vehicle and remove exhaust pipe from manifold.
10. Remove power steering pump and set aside. Do not disconnect lines.
11. Remove accessory drive bracket
12. Remove ignition coil and wires from engine.
13. Disconnect cam sensor and fuel injector wiring connectors.
14. Remove timing belt and camshaft sprockets.
15. Remove timing belt idler pulley and rear timing belt cover.
16. Remove cylinder head cover.
17. Remove camshafts.
NOTE: Identify rocker arm position to ensure correct reinstallation in original position, if reused.
18. Remove rocker arms.
19. Remove cylinder head bolts in REVERSE sequence of tightening.
20. Remove cylinder head from engine block.
21. Inspect and clean cylinder head.
CLEANING
To ensure engine gasket sealing, proper surface preparation must be performed, especially with the use of aluminum engine components and multi-layer steel cylinder head gaskets.
NOTE: Multi-Layer Steel (MLS) head gaskets require a scratch free sealing surface.
Remove all gasket material from cylinder head and block. Be careful not to gouge or scratch the aluminum head sealing surface.
Clean all engine oil passages.
INSPECTION
1. Cylinder head must be flat within 0.1 mm (0.004 inch) (Fig. 7).
2. Inspect camshaft bearing journals for scoring.
3. Remove carbon and varnish deposits from inside of valve guides with a reliable guide cleaner.
4. Using a small hole gauge and a micrometer, measure valve guides in 3 places top, middle and bottom (Fig. 8). Replace guides if they are not within specification.
5. Check valve guide height (Fig. 9).
INSTALLATION - CYLINDER HEAD
NOTE: The Cylinder head bolts should be examined BEFORE reuse. If the threads are necked down, the bolts must be replaced (Fig. 10).
Necking can be checked by holding a scale or straight edge against the threads. If all the threads do not contact the scale, the bolt should be replaced.
1. Before installing the bolts, the threads should be coated with engine oil.
2. Position cylinder head gasket on engine block (Fig. 11).
3. Install cylinder head on engine block.
4. Tighten the cylinder head bolts in the sequence shown in (Fig. 12). Using the 4 step torque turn method, tighten according to the following values:
^ First All to 34 Nm (25 ft. lbs.)
^ Second All to 68 Nm (50 ft. lbs.)
^ Third All to 68 Nm (50 ft. lbs.)
CAUTION: Do not use a torque wrench for the following step.
^ Fourth Turn an additional 1/4 Turn,
5. Install rocker arms.
6. Install camshafts.
7. Install cylinder head cover.
8. Install timing belt rear cover and timing belt idler pulley.
9. Install timing belt and camshaft sprockets.
10. Connect cam sensor and fuel injectors wiring connectors.
11. Install ignition coil and wires. Connect ignition coil wiring connector.
12. Install accessory drive bracket.
13. Install power steering pump to cylinder head.
14. Raise vehicle and install the exhaust pipe to the manifold.
15. Install accessory drive belts.
16. Install heater tube support bracket to cylinder head.
17. Install intake manifold.
18. Connect all vacuum lines, electrical wiring, ground straps and fuel line.
19. Fill cooling system.
20. Connect battery negative cable.