Cylinder Head Assembly: Service and Repair
REMOVAL
1. Relieve fuel pressure according to procedure. Refer to Powertrain Management; Fuel Delivery and Air Induction.
2. Disconnect negative cable at battery.
3. Drain engine oil.
4. Drain coolant.
5. Remove ignition coil cover.
6. Remove air cleaner case with air cleaner outlet hose.
7. Disconnect accelerator cable from throttle body.
8. Remove accelerator cable from bracket.
9. Disconnect the following hoses:
^ Brake booster hose from intake manifold
^ Coolant hose from throttle body
^ Fuel feed hose from delivery pipe
^ Fuel return hose from fuel return pipe
^ Heater hose from water outlet cap
^ Radiator inlet hose from water outlet cap
^ Vacuum hose from EVAP canister purge valve
10. Disconnect the following electric lead wires:
^ IAC valve coupler
^ TP sensor coupler
^ MAF sensor coupler
^ EGR valve coupler
^ EVAP canister purge valve coupler
^ MDP sensor coupler
^ Ground terminals from cylinder head and throttle body
^ ECT sensor coupler
^ CMP sensor coupler
^ Injector wire harness coupler
^ Ignition coil couplers
^ Wire harness clamps
11. Remove intake manifold rear stiffener.
12. Disconnect coolant pipe from intake manifold.
13. Remove timing chain cover.
14. Remove 1st timing chain.
15. Remove camshafts and valve lash adjuster.
16. Remove engine RH mounting bracket.
17. Disconnect P/S pump and generator from P/S pump bracket. If mounting bolts of P/S pump cannot be removed, remover front torque bush and rear mounting from mounting member and raise engine by using lifting device and remove bolts.
CAUTION: Do not raise engine excessively. That may cause damage to engine, transmission, etc.
18. Remove P/S pump bracket.
19. Install engine rear mounting No.2 bracket front torque bush and rear mounting to mounting member to stabilize engine if removed.
Loosen cylinder head bolts in such order as numbered in figure and remove them.
NOTE: Don't forget to remove bolt (M6) as shown In figure.
20. Check all around cylinder head for any other parts required to be removed or disconnected and remove or disconnect whatever necessary.
21. Remove cylinder head with intake manifold, exhaust manifold and water outlet cap.
NOTE: Be careful not to damage fins of radiator.
DISASSEMBLY
1. When servicing cylinder head, remove intake manifold, injectors, exhaust manifold and water outlet cap from cylinder head.
2. Using special tools, compress valve springs and then remove valve cotters also by using special tool.
Special Tools
(A): 09916-14510
(B): 09916-14910
(C): 09919-28610
(D): 09916-84511
3. Release special tool, and remove spring retainers and valve springs.
4. Remove valve from combustion chamber side.
5. Remove valve stem seal from valve guide, and then valve spring seat.
NOTE: Do not reuse seal once disassembled. Be sure to use new seal when assembling.
6. 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.
7. Place disassembled parts except valve stem seal and valve guide in order so that they can be installed in their original positions.
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.
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 chamber. When it is worn out so 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.
Limit on valve head radial runout: 0.08 mm (0.003 inch)
^ 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 cuffing 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 valve seat: 1.1 - 1.3 mm (0.0433 - 0.0512 inch)
2. INTAKE VALVE SEAT: Use valve seat cutters 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 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)
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 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 chaffer, 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 as to remove burrs and make it truly round.
Special Tools
(A): 09916-34542
(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 13.5 mm (0.53 inch) from cylinder head.
Special Tools
(A): 09916-58210
(B): 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 Tools
(A): 09916-34542
(B): 09916-37810
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): 09919-28610
(D): 09916-84511
9. Install intake manifold, injectors, exhaust manifold and water outlet cap to cylinder head.
INSTALLATION
1. Match match mark on crank timing sprocket and mating surface of cylinder block and lower crankcase.
2. Clean mating surface of cylinder head and cylinder block.
Remove oil, old gasket and dust from mating surface.
3. Install knock pins to cylinder block.
4. Install new cylinder head gasket to cylinder block. Top mark provided on gasket comes to crankshaft pulley side, facing up (toward cylinder head side).
5. Install cylinder head to cylinder block.
Apply engine oil to cylinder head bolts and tighten them gradually as follows.
1. Tighten all bolts to 53 Nm (5.3 kg-m, 38.5 ft. lbs.) according to numerical order in figure.
2. In the same manner as in (1), retighten them to 84 Nm (8.4 kg-m, 61.0 ft. lbs.).
3. Loosen all bolts until tightening torque is reduced to 0 according to numerical order in figure.
4. Tighten all bolts to 37 Nm (3.7 kg-m, 27.0 ft. lbs.) according to numerical order in figure.
5. In the same manner as in (4), retighten them to specified torque.
Tightening Torque
(a): 105 Nm (10.5 kg-m, 76.0 ft. lbs.)
(b): 11 Nm (1.1 kg-m, 8.0 ft. lbs.)
NOTE: Be sure to tighten M6 bolt after securing other bolts.
6. Install engine RH mounting bracket.
Tighten bracket bolts to specified Torque.
Tightening Torque (a): 55 Nm (5.5 kg-m, 40.0 ft. lbs.)
7. Install P/S pump bracket.
8. Install P/S pump and generator to P/S pump bracket.
9. Install camshafts and valve lash adjuster.
10. Install 1st timing chain.
11. Install 2nd timing chain.
12. Install timing chain cover.
13. Reverse removal procedure for installation.
14. Adjust accelerator cable play.
15. Check to ensure that all removed parts are back in place.
Reinstall any necessary parts which have not been reinstalled.
16. Refill engine with engine oil.
17. Refill cooling system.
18. Connect negative cable at battery.
19. Check ignition timing and adjust as necessary, referring to Ignition System; Ignition Timing.
20. Verify that there is no fuel leakage, coolant leakage, oil leakage and exhaust gas leakage at each connection.