Cylinder Head Assembly: Service and Repair
Valves and Cylinder Head Removal and Installation
Removal
1) Remove engine assembly from vehicle.
2) Remove timing chain cover.
3) Remove 2nd timing chain and 1st timing chain.
4) Remove camshafts and valve lash adjuster.
5) Remove intake manifold rear stiffener (1).
6) Disconnect coolant pipe (1) from intake manifold.
7) Remove engine RH mounting bracket (1).
8) Remove P/S pump bracket (1).
9) Loosen cylinder head bolts in such order as numbered in figure and remove them.
NOTE: Don't forget to remove bolt (M6) (3) as shown in figure.
10) Check all around cylinder head for any other parts required to be removed or disconnected and remove or disconnect whatever necessary.
11) Remove cylinder head with intake manifold, exhaust manifold and water outlet cap. Use lifting device, if necessary.
Installation
1) Match match mark (1) on crank timing sprocket and mating surface (2) of cylinder block and lower crankcase.
2) Clean mating surface of cylinder head and cylinder block (2). Remove oil, old gasket and dust from mating surface.
3) Install knock pins (3) to cylinder block.
4) Install new cylinder head gasket (1) to cylinder block. Top mark (6) provided on gasket comes to crankshaft pulley side (4), 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.
a) Tighten all bolts to 53 Nm (5.3 kgf-cm, 38.5 ft. lbs.).
b) In the same manner as in step a), retighten them to 84 Nm (8.4 kgf-cm, 61.0 ft. lbs.).
c) Loosen all bolts until tightening torque is reduced to 0.
d) Tighten all bolts to 53 Nm (5.3 kgf-cm, 38.5 ft. lbs.).
e) In the same manner as in step b), retighten them to specified torque.
Tightening torque
Cylinder head bolts (a): 105 Nm (10.5 kgf-cm, 76.0 ft. lbs.)
Cylinder head bolt (hex hole bolt) (b): 11 Nm (1.1 kgf-cm, 8.0 ft. lbs.)
NOTE: Be sure to tighten M8 bolt (3) after securing other bolts.
6) Install engine RH mounting bracket (1).
Tighten bracket bolts to specified torque.
Tightening torque
Engine RH mounting bracket bolts (a): 55 Nm (5.5 kgf-cm, 40.0 ft. lbs.)
7) Install P/S pump bracket.
8) Install camshafts and valve lash adjuster.
9) Install 1st timing chain.
10) Install 2nd timing chain.
11) Install timing chain cover.
12) Install engine assembly to vehicle.
Valves and Cylinder Head Disassembly and Assembly
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 (1) also by using special tool.
Special Tool
(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 (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.
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.
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 Tool
(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 contacts cylinder head.
After installing, make sure that valve guide protrudes by 13.5 mm (0.53 inch) from cylinder head.
Special Tool
(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 "a" (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
(A): 09916-34542
(B): 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
(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 (1)) and bottom end (small-pitch end (2)). 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 (1) into groove in valve stem.
Special Tool
(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.
Valves and Cylinder Head 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 and valve guide
Valve stem diameter
In
Standard 5.965 - 5.980 mm (0.2348 - 0.2354 inch)
Ex 5.940 - 5.955 mm (0.2339 - 0.2344 inch)
Valve guide I.D.
In & Ex
Standard 6.000 - 6.012 mm (0.2362 - 0.2366 inch)
Stem-to-guide clearance
In
Standard 0.020 - 0.047 mm (0.0008 - 0.0018 inch)
Limit 0.07 mm (0.0027 inch)
Ex
Standard 0.045 - 0.072 mm (0.0018 - 0.0028 inch
Limit 0.09 mm (0.0035 inch)
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 (1) of valve head. If measured thickness exceeds limit, replace valve.
Valve specification
In
Standard 1.0 mm (0.039 inch)
Limit 0.6 mm (0.024 inch)
Ex
Standard 1.2 mm (0.047 inch)
Limit 0.7 mm (0.028 inch)
^ 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.
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 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 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 in intake and exhaust ports, combustion chambers, and head surface at a total of 6 locations. If distortion limit 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, check to be sure that each spring is in standard 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
INNER
Standard 36.08 mm (1.4204 inch)
Limit 35.00 mm (1.3780 inch)
OUTER
Standard 40.44 mm (1.5921 inch)
Limit 39.22 mm (1.544 inch)
Valve Spring preload
INNER
Standard 6.9 - 7.9 kgf for 27.5 mm (15.2 - 17.4 lbs./1.08 inch)
Limit 6.2 kgf for 27.5 mm (13.6 lbs. /1.08 inch)
OUTER
Standard 15.4 - 17.8 kgf for 31.7 mm (33.9 - 39.2 lbs. /1.25 inch)
Limit 13.8 kgf for 31.7 mm (30.4 lbs. /1.25 inch)
^ 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 must be replaced.
Valve spring squareness limit: 2.0 mm (0.079 inch)