Cylinder Head Assembly: Service and Repair
REMOVAL
1. Relieve fuel pressure according to procedure described in section 6.
2. Disconnect negative cable at battery.
3. Drain cooling system.
4. Remove air cleaner outlet hose as previously outlined.
5. Remove intake manifold rear stiffener bolt, generator adjust arm reinforcement bolt and right mounting bracket stiffener bolt from intake manifold.
6. Disconnect heated oxygen sensor coupler and release its clamps.
7. Remove exhaust manifold cover.
8. Remove exhaust No.1 pipe mounting nuts (3 pcs.).
9. Disconnect following electric wires:
^ Ignition coil
^ ECT sensor
^ Ground wire from intake manifold and throttle body
^ EGR valve
^ Injectors
^ TP sensor
^ IAC valve
^ Heated oxygen sensor
^ EVAP canister purge valve
^ MAP sensor
^ Tank pressure control solenoid vacuum valve
^ CMP sensor and then release above wire harnesses from clamps.
10. Disconnect vacuum hoses:
^ EVAP canister purge hose from solenoid purge valve
^ Brake booster hose from intake manifold
^ Tank pressure control solenoid vacuum hose from tank pressure control valve
11. Disconnect fuel feed hose from feed pipe and disconnect fuel return hose from fuel pressure regulator.
12. Remove cylinder head cover as previously outlined.
Loosen all valve lash adjusting screws fully.
13. Disconnect engine cooling water (coolant) hoses.
^ Radiator inlet hose
^ Heater inlet hose
^ IAC valve outlet hose
14. Remove timing belt and camshaft.
15. Loosen cylinder head bolts in such order as indicated in figure and remove them.
16. Check all around cylinder head for any other parts required to be removed or disconnected and remove or disconnect whatever necessary.
17. Remove cylinder head with intake manifold, exhaust manifold and ignition coil assembly, using lifting device.
DISASSEMBLY
1. For ease in servicing cylinder head, remove distributor gear case, intake manifold with throttle body and exhaust manifold from cylinder head.
2. Remove camshaft as previously outlined and remove rocker arms and washers by pulling its shaft out to transmission side.
3. Using special tool (Valve lifter), compress valve springs and then remove valve cotters by using special tool (Forceps) as shown.
Special Tools
(A): 09916-14510
(B): 09916-14910
(C): 09916-84510
4. Release special tool, and remove spring retainer and valve spring.
5. Remove valve from combustion chamber side.
6. Remove valve stem oil seal from valve guide, and then valve spring seat.
NOTE: Do not reuse oil seal once disassembled. Be sure to use new oil seal when assembling.
7. Using special tool (Valve guide remover), drive valve guide out from combustion chamber side to valve spring side.
Special Tool
(A): 09916-44910
NOTE: Do not reuse valve guide once disassembled. Be sure to use new valve guide (Oversize) when assembling.
8. Place disassembled parts except valve stem seal and valve guide in order, so that they can be installed in their original position.
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.
If bore gauge is not available, check end deflection of valve stem with a dial gauge instead.
Move stem end in directions (1. and 2.) to measure end deflection. If deflection exceeds its limit, replace valve stem and valve guide.
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.
^ Inspect valve stem end face for pitting and wear. If pitting or wear is found there, valve stem end may be resurfaced, but not so much as to grind off its chamfer. When it is worn so much that its chamfer is gone, replace valve.
^ Seating contact width:
Create contact pattern on 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.
^ 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.
1. EXHAUST VALVE SEAT: Use valve seat cutters to make two cuts as illustrated in 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)
2. INTAKE VALVE SEAT: Cutting sequence is the same as for exhaust valve seats.
Seat width for intake valve seat: 1.1 - 1.3 mm (0.0433 - 0.0512 inch)
3. 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 in intake and exhaust ports, combustion chambers, and head surface.
^ Flatness of gasketed surface:
Using a straightedge and thickness gauge, check surface at a total of 6 locations. If distortion limit, given below, is exceeded, correct gasketed surface with a surface plate and abrasive paper of about #400 (Waterproof silicon carbide abrasive paper): place 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.
Limit of distortion: 0.05 mm (0.002 inch)
^ Distortion of manifold seating faces:
Check seating faces of cylinder head for manifolds, using a straightedge and thickness gauge, in order to determine whether these faces should be corrected or cylinder head replaced.
Limit of distortion: 0.10 mm (0.004 inch)
Valve Springs
^ 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.
^ 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 below must be replaced.
Valve spring squareness limit: 2.0 mm (0.079 inch)
ASSEMBLY
1. Before installing valve guide into cylinder head, ream guide hole with special tool (11 mm reamer) so remove burrs and make it truly round.
Special Tools
(A): 09916-34541
(B): 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 by 11.5 mm (0.45 inch) from cylinder head.
Special Tools
(C): 09916-56011
(D): 09916-58210
NOTE:
^ Do not reuse valve guide once disassembled. Install now 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): 11.5 mm (0.45 inch)
3. Ream valve guide bore with special tool (5.5 mm reamer).
After reaming, clean bore.
Special Tools
(A): 09916-34541
(B): 09916-34550
4. Install valve spring seat to cylinder head.
5. Install new valve stem seal 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 Tools
(A): 09917-98221
(B): 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 to valve guide.
Before installing valve to valve guide, apply engine oil to stem seal, valve guide bore, and valve stem.
7. Install valve spring and spring retainer.
Each valve spring has top end (large-pitch end) and bottom end (small-pitch end). Be sure to position spring in place with its bottom end (small-pitch end) facing the bottom (valve spring seat side).
8. Using special tool (Valve lifter), compress valve spring and fit two valve cotters into groove in valve stem.
Special Tools
(A): 09916-14510
(B): 09916-14910
(C): 09916-84510
9. Install rocker arms, washers, rocker arm shaft and camshaft as previously outlined.
10. Install CMP sensor case, intake manifold and exhaust manifold.
INSTALLATION
1. Remove oil gasket and oil on mating surfaces and install new head gasket as shown in figure, that is, "TOP" mark provided on gasket comes to crankshaft pulley side, facing up (toward cylinder head side).
2. Check to make sure that oil jet (venturi plug) is installed and if it is. that it is not clogged.
When installing it, be sure to tighten to specified torque.
Tightening Torque (a): 5 Nm (0.5 kg-m, 4.0 ft. lbs.)
3. Apply engine oil to cylinder head bolts and tighten them gradually as follows.
1. Tighten all bolts to 35 Nm (3.5 kg-m, 25.0 ft. lbs.) according to numerical order in figure.
2. In the same manner as in 1., tighten them to 55 Nm (5.5 kg-m, 40.0 ft. lbs.).
3. In the same manner as in 1. again, tighten them to specified torque.
Tightening Torque (a): 68 Nm (6.8 kg-m, 49.5 ft. lbs.)
4. Reverse removal procedure for installation.
5. Adjust drive belt tension.
6. Adjust power steering pump belt tension or A/C compressor belt tension, if equipped.
7. Adjust intake and exhaust valve lashes as previously outlined.
8. Adjust accelerator cable play.
9. Check to ensure that all removed parts are back in place. Reinstall any necessary parts which have not been reinstalled.
10. Refill cooling system.
11. Connect negative cable at battery.
12. Inspect ignition timing referring to Ignition Systems; Ignition Timing.
13. Verify that there is no fuel leakage, water leakage and exhaust gas leakage at each connection.