Cylinder Head Assembly: Service and Repair
Removal1. Relieve fuel pressure.
2. Disconnect negative (-) cable at battery.
3. Drain engine oil.
4. Drain coolant.
5. Remove CMP sensor, camshaft and valve lash adjuster.
6. Remove exhaust manifold.
7. Remove water outlet cap.
8. Loosen cylinder head bolts in such order ("1" - "8") as shown in the figure and remove them.
NOTE: Don't forget to remove 2 hex bolts (1) shown in the figure.
9. Remove cylinder heads.
Installation
1. Clean mating surface on cylinder head and cylinder block. Remove oil, old gasket and dust from mating surface.
2. Install knock pin (4) to cylinder block.
3. Apply sealant "A" to cylinder head gasket (1) as shown in the figure.
"A": Sealant 99000-31150
Sealant amount
Width "w": 4 mm (0.158 inch)
4. Install new cylinder head gasket (1) to cylinder block as shown in the figure, carved lot number (5) on cylinder head gasket (1) should face up (toward cylinder head side).
5. Install cylinder head to block.
After applying oil to cylinder head bolts, tighten them gradually as follows.
a. Tighten all bolts to 53 Nm (5.3 kgf-m, 38.5 ft. lbs.) according to numerical order in the figure.
b. In the same manner as in a), tighten them to 84 Nm (8.4 kgf-m, 61.0 ft. lbs.).
c. Loosen all bolts until tightening torque is reduced to 0 in reverse order of tightening.
d. In the same manner as in a), tighten them to 53 Nm (5.3 kgf-m, 38.5 ft. lbs.).
e. In the same manner as in a) again, tighten them to specified torque.
Tightening torque
Cylinder head bolt (a): 105 Nm (10.5 kgf-m, 76.0 ft. lbs.)
Cylinder head bolt (hex hole bolt) (b): 11 Nm (1.1 kgf-m, 7.5 ft. lbs.)
NOTE: Don't forget to install hex hole bolts (1) as shown in the figure.
6. Install water outlet cap.
7. Check timing mark on crankshaft as shown in the figure.
8. Install valve lash adjuster, camshaft, CMP sensor and RH bank 2nd timing chain.
9. Install 1st timing chain.
10. Install LH bank 2nd timing chain.
11. Install timing chain cover.
12. Install oil pan and oil pump strainer.
13. Install cylinder head cover.
14. Install exhaust manifold.
15. Install radiator outlet pipe, radiator, cooling fan and water hose.
16. Install throttle body and intake manifold.
17. Adjust water pump drive belt tension.
18. Adjust power steering pump drive belt tension.
19. Adjust accelerator cable play and A/T throttle cable play.
20. Check to ensure that all removed parts are back in place. Reinstall any necessary parts which have not been reinstalled.
21. Refill engine with engine oil.
22. Refill cooling system.
23. Refill front differential housing with gear oil if drained.
24. Connect negative cable at battery.
25. Check ignition timing and adjust as necessary.
26. Verify that there is no fuel leakage, water leakage, oil leakage and exhaust gas leakage at each connection.
27. Check wheel alignment.
Disassembly
1. Using special tools (A), (B) and (C), compress valve springs and then remove valve coffers (1) by using special (D)
2. Release special tool and remove spring retainer and valve spring.
Special tool
(A): 09916-14510
(B): 09916-14910
(C): 09919-28610
(D): 09916-84511
3. Remove valve from combustion chamber side.
4. Remove valve stem seal (1) from valve guide, and then valve spring seat (2).
NOTE: Do not reuse seal once disassembled. Be sure to use new seal when assembling.
5. Using special tool (E) (Valve guide remover), drive valve guide out from combustion chamber side to valve spring side.
Special tool
(E): 09916-44910
NOTE: Do not reuse valve guide once disassembled. Be sure to use new valve guide (Oversize) when assembling.
6. Place disassembled parts except valve stem seal and valve guide in order so that they can be installed in their original positions.
Reassembly
1. Before installing valve guide into cylinder head ream guide hole with special tool (11 mm reamer) so as to remove burrs and make it truly round.
Special tool
(E): 09916-34542
(F): 09916-38210
2. Install valve guide to cylinder head.
Heat cylinder head uniformly at a temperature of 80 to 100°C (176 to 212°F) so that head will not be distorted, and drive new valve guide into hole with special tools. Drive in new valve guide until special tool (Valve guide installer) contacts cylinder head.
After installing, make sure that valve guide protrudes (1) by 13.5 mm (0.53 inch) from cylinder head.
Special tool
(G): 09916-58210
(H): 09917-87810
NOTE:
^ Do not reuse valve guide once disassembled. Install new valve guide (Oversize).
^ Intake and exhaust valve guides are identical.
Valve guide oversize 0.03 mm (0.0012 inch)
Valve guide protrusion (In and Ex) 13.5 mm (0.53 inch)
3. Ream valve guide bore with special tool (6.0 mm reamer). After reaming, clean bore.
Special tool
(E): 09916-34542
(I): 09916-37810
4. Install valve spring seat to cylinder head.
5. Install new valve stem seal (1) to valve guide.
After applying engine oil to seal and spindle of special tool (Valve guide installer handle), fit oil seal to spindle, and then install seal to valve guide by pushing special tool by hand.
After installing, check to be sure that seal is properly fixed to valve guide.
Special tool
(J): 09917-98221
(K): 09916-58210
NOTE:
^ Do not reuse seal once disassembled. Be sure to install new seal.
^ When installing, never tap or hit special tool with a hammer or else. Install seal to guide only by pushing special tool by hand. Tapping or hitting special tool may cause damage to seal.
6. Install valve (1) to valve guide.
Before installing valve to valve guide, apply engine oil to stem seal, valve guide bore, and valve stem.
7. Install valve springs (inner and outer) and spring retainer.
Each valve spring has top end (large-pitch end (1) and bottom end (small-pitch end (2). Be sure to position spring in place with its bottom end (valve spring retainer side (3) facing the bottom (valve spring seat side (4).
8. Using special tool (Valve lifter), compress valve spring and fit 2 valve coffers (1) into groove in valve stem.
Special tool
(A): 09916-14510
(B): 09916-14910
(C): 09916-84511
(D): 09919-28610
Inspection
Valve Guides
Using a micrometer and bore gauge, take diameter readings on valve stems and guides to check stem-to-guide clearance. Be sure to take reading at more than one place along the length of each stem and guide. If clearance exceeds limit, replace valve and valve guide.
Valve stem-to-guide clearance
Valves
^ Remove all carbon from valves.
^ Inspect each valve for wear, burn or distortion at its face and stem and, as necessary, replace it.
^ Measure thickness of valve head. If measured thickness exceeds limit, replace valve.
Valve specification
^ Inspect valve stem end face for pitting and wear. If pitting or wear is found there, valve stem end may be resurfaced, but not too much to grind off its chamber. When it is worn out too much that its chamber is gone, replace valve.
^ Check each valve for radial runout with a dial gauge and "V" block.
To check runout, rotate valve slowly. If runout exceeds its limit, replace valve
Valve head radial runout limit 0.08 mm (0.003 inch)
^ Seating contact width
Create contact pattern one each valve in the usual manner, i.e., by giving uniform coat of marking compound to valve seat and by rotatingly tapping seat with valve head. Valve lapper (tool used in valve lapping) must be used.
Pattern produced on seating face of valve must be a continuous ring without any break, and the width of pattern must be within specified range.
Standard seating width revealed by contact pattern on valve face
Intake and Exhaust: 1.1 - 1.3 mm (0.0433 - 0.0512 inch)
^ Valve seat repair
A valve seat not producing a uniform contact with its valve or showing width of seating contact that is out of specified range must be repaired by regrinding or by cutting and regrinding and finished by lapping.
a. Exhaust valve seat
Use valve seat cutters (1) to make two cuts as illustrated in the figure. Two cutters must be used: the first for making 15° angle, and the second for making 45° angle. The second cut must be made to produce desired seat width.
Seat width for exhaust valve seat 1.1 - 1.3 mm (0.0433 - 0.0512 inch)
b. Intake valve seat
Use valve seat cutters (1) to make three cuts as illustrated in figure. Three cutters must be used: the 1st for making 15° angle, the 2nd for making 60° angle, and the 3rd for making 45° angle. The 3rd cut (45°) must be made to produce desired seat width.
Seat width for intake valve seat 1.1 - 1.3 mm (0.0433 - 0.0512 inch)
c. Valve lapping
Lap valve on seat in two steps, first with coarse size lapping compound applied to face and the second with fine size compound, each time using valve lapper according to usual lapping method.
Cylinder Head
^ Remove all carbon from combustion chambers.
NOTE: Do not use any sharp-edged tool to scrape off carbon. Be careful not to scuff or nick metal surfaces when decarboning. The same applies to valves and valve seats, too.
^ Check cylinder head for cracks on intake and exhaust ports, combustion chambers, and head surface.
Using straightedge (1) and thickness gauge (2), check flatness of gasketed surface at a total of 6 locations. If distortion limit given, is exceeded, correct gasketed surface with a surface plate and abrasive paper of about #400 (Waterproof silicon carbide abrasive paper): Place abrasive paper on and over surface plate, and rub gasketed surface against paper to grind off high spots. Should this fail to reduce thickness gauge readings to within limit, replace cylinder head.
Leakage of combustion gases from this gasketed joint is often due to warped gasketed surface: such leakage results in reduced power output.
Cylinder head gasketed surface distortion limit 0.05 mm (0.002 inch)
^ Distortion of manifold seating faces
Check seating faces of cylinder head for manifolds, using a straightedge (1) and thickness gauge (2), in order to determine whether these faces should be corrected or cylinder head replaced.
Manifold seating surface distortion limit 0.10 mm (0.004 inch)
Valve Spring
^ Referring to data given, check to be sure that each spring is in sound condition, free of any evidence of breakage or weakening. Remember, weakened valve springs can cause chatter, not to mention possibility of reducing power output due to gas leakage caused by decreased seating pressure.
Valve spring free length
Valve spring preload
^ Spring squareness
Use a square and surface plate to check each spring for squareness in terms of clearance between end of valve spring and square. Valve springs found to exhibit a larger clearance than limit given must be replaced.
Valve spring squareness limit
Inner spring: 1.6 mm (0.063 inch)
Outer spring: 1.8 mm (0.071 inch)