Cylinder Head Assembly: Service and Repair
CYLINDER HEADRemoval
1. Remove timing belt, belt cover and related parts. (Refer to "Timing Belt and Belt Cover".)
2. Remove turbo cooling pipe together with union screws and gaskets from cylinder head. [TURBO model]
3. Remove camshaft cases, lash adjuster and related parts. Service and Repair
4. Remove plug attaching EGR pipe to cylinder head. [Except TURBO model]
5. Remove bolt attaching alternator bracket to cylinder head. [Except air conditioner model]
6. Remove bolt attaching adjusting bar to cylinder head. [Except air conditioner model].
7. Remove bolts attaching intake manifold to cylinder head, and then lift intake manifold from cylinder head.
8. Remove bolt attaching water by-pass pipe bracket to cylinder head.
9. Remove spark plugs.
10. Remove cylinder heads and gaskets from cylinder block.
VALVE AND VALVE SPRING
Removal
1. Using VALVE SPRING PRESS ASSY (899724100), compress the valve spring and remove the valve spring retainer key. Remove each valve and valve spring.
a. Mark each valve to prevent confusion.
b Use extreme care not to damage the lips of the intake valve oil seals and exhaust valve oil seals.
INTAKE AND EXHAUST VALVE
1. Inspect the flange and stem of valve, and replace if damaged, worn, or deformed, or if "H" is less than the specified limit.
H:
TURBO Intake & Non-TURBO Standard
1.3 mm (0.051 in).
Limit
0.8 mm (0.031 in).
TURBO Exhaust
Standard
1.8 mm (0.071 in).
Limit
1.3 mm (0.051 in).
VALVE OVERALL LENGTH:
TURBO Intake & Non-TURBO 107.58 mm (4.235 in).
TURBO Exhaust 108.1 mm (4.256 in).
2. If the contact surface of valve is damaged, or if the stem end is recessed, correct with a valve refacer, grinding as little as possible. The contact surface should be at right angle with the Valve axis. [Intake valve only].
3. Put a small amount of grinding compound on the seat surface and lap the valve and seat surface. Also refer to Cylinder Head Inspection, Step # 3, below) at this time. Install a new intake valve oil seal after lapping.
VALVE SPRINGS
1. Check valve springs for damage, free length, and tension. Replace valve spring if it is not to the specifications presented below.
2. To measure the squareness of the valve spring, stand the spring on a surface plate and measure its deflection at the top using a try square.
INSPECTION
CYLINDER HEAD
1. Make sure that no crack or other damage exists. In addition to visual inspection, inspect important areas by means of red check.
2. Measure the warping of the cylinder head surface that mates with crankcase by using a straight edge and thickness gauge. If the warping exceeds 0.05 mm (0.0020 in), regrind the surface with a surface grinder.
Warping limit:
0.05 mm (0.0020 in).
Grinding limit:
0.3 mm (0.012 in).
Standard height of cylinder head:
90.6 mm (3.567 in).
Uneven torque for the cylinder head nuts can cause warping. When reassembling, pay special attention to the torque so as to tighten evenly.
3. Inspect intake and exhaust valve seats, and correct the contact surfaces with valve seat cutter if they are defective or when valve guides are replaced.
W:
Intake:
1.2 - 1.8 mm (0.047 - 0.071 in).
Exhaust:
1.5 - 2.0 mm (0.059 - 0.079 in).
Wear limit of valve seat (measured in direction of valve axis): 0.5 mm (0.020 in) for both intake and exhaust valves.
VALVE GUIDE
1. Check the clearance between valve guide and stem. The clearance can be checked by measuring the outside diameter of valve stem and the inside diameter of valve guide with outside and inside micrometers respectively.
2. If the clearance between valve guide and stem exceeds the specification, replace guide as follows:
a. Place the cylinder head on the CYLINDER HEAD TABLE with the combustion chamber upward so that valve guides enter the holes in the CYLINDER HEAD TABLE.
b. Insert VALVE GUIDE REMOVER into valve guide and press it down to remove guide.
c. Turn cylinder head upside down and place VALVE GUIDE ADJUSTER as shown in the figure.
d. Before installing new valve guide, make sure that neither scratches nor damages exist on the inside surface of the valve guide holes in cylinder head.
5. Put new valve guide, coated with sufficient oil in cylinder, and insert VALVE GUIDE REMOVER into valve guide. Press in until the valve guide upper end is flush with the upper surface of VALVE GUIDE ADJUSTER.
6. Check the valve guide protrusion.
Valve guide protrusion: L
17 - 18.5 mm (0.689 - 0.728 in).
7. Ream the inside of valve guide with VALVE GUIDE REAMER (399762104). Gently rotate the reamer clockwise while pressing it lightly into valve guide, and return it also rotating clockwise. After reaming, clean valve guide to remove chips.
a. Apply engine oil to the reamer when reaming.
b. If the inner surface of the valve guide is torn, the edge of the reamer should be slightly ground with an oil stone.
c. If the inner surface of the valve guide becomes lustrous and the reamer does not cut chips, use a new reamer or remedy the reamer.
8. Recheck the contact condition between valve and valve seat after replacing valve guide.
INTAKE AND EXHAUST VALVE OIL SEAL
Replace oil seal with new one, if lip is damaged or spring is out of place, or when the surfaces of intake valve and valve seat are reconditioned or intake valve guide is replaced.
Press in oil seal to the specified dimension indicated in the figure, using OIL SEAL INSTALLER (398852100).
a. Apply engine oil to oil seal before force-fitting.
b. Differentiate between intake valve oil seal and exhaust valve oil seal by noting their difference in height.
ASSEMBLY
1. Install the oil seal to the valve guides using OIL SEAL INSTALLER (398852100).
2. Coat the stem of each valve with engine oil and insert the valve into the valve guide. Attach the valve springs and retainer. Then compress the valve springs using VALVE SPRING PRESS (899724100) and fit the valve spring retainer key.
a. After installing, tap the valve spring retainers lightly with a wooden hammer for better seating.
b. When inserting the valve into the valve guide, use special care not to damage the oil seal lip.
c. Be sure to install the valve springs with their close-coiled end facing the seat on the cylinder head.
Cylinder Head:
3. Install cylinder heads to cylinder block with new gaskets. When tightening bolts, apply oil to the threads and tighten them in two or three successive steps until the final tightening is at the specified torque. In each step, tighten them in the specified sequence
1st step:
29 N.m (3.0 kg-m, 22 ft-lb).
2nd step:
59 N.m (6.0 kg-m, 43 ft-lb.
3rd (final) step:
64 N.m (6.5 kg-m, 47 ft-lb)
4. Install spark plugs.
Tightening torque:
18 - 24 N.m (1.8 - 2.4 kg-m, 13 - 17 ft-lb).
5. Install bolt attaching water by-pass pipe bracket to cylinder head.
6. Install bolts attaching intake manifold to cylinder head.
Tightening torque:
18 - 22 N.m(1.8 - 2.2 kg-m, 13 - 16 ft-lb),
7. Install plug attaching EGR pipe to cylinder head. [Except TURBO model]
Tightening torque:
31 - 37 N.m (3.2 - 3.8 kg-m, 23 - 27 ft-lb).
8. Install TURBO cooling pipe together with union screws and gaskets to cylinder head. [TURBO model).
Tightening torque:
21.1 - 24.0 N.m (2.15-2.45 kg-m, 15.6 - 17.7 ft-lb).
9. Install bolt attaching adjusting bar to cylinder head.
Tightening torque:
16 - 22 N.m (1.6 - 2.2 kg-m, 12 - 16 ft-lb).
10. Install bolts attaching alternator bracket to cylinder head.
Tightening torque:
36 - 42 N.m (3.7 - 4.3 kg-m, 27 - 31 ft-lb).
11. Install camshaft cases, lash adjustor and related parts.
12. Install timing belt, belt cover and related parts. (Refer to "Timing Belt and Belt Cover".) Service and Repair
After completing engine ASSY and mounting engine on car, he sure to retighten cylinder head bolts.
RETORQUING
1. Warm up engine.
2. After engine has cooled down, remove right and left valve rocker covers.
3. Loosen intake manifold (No.1 and No.3 cylinders side) mounting bolts (three) by 60°. Do not loosen mounting bolts of manifold for No.2 and No.4 cylinders. See TSB 02-85-91.
Do not loosen the mounting bolts mare than 90°, or water. may leak.
4. Loosen bolt at position #1 in Figure, and apply oil to the thread. Repeat "loosen and tighten" operation four to five times within the 60° range for a better fit, then tighten bolt to the specified torque.
Specified torque:
64 N.m (6.5 kg-m, 47 ft-lb).
5. Similarly, retighten each bolt in the sequence from #2 to #9 as shown in Figure.
Finally, retighten bolt # 1 to the specified torque without loosening.
6. After retightening right and left cylinder head bolts, tighten six mounting bolts of intake manifolds (No.1 and No.3) (No.2 and No.4). See TSb 02-85-91.