Cleaning/Inspection
CLEANING AND INSPECTION PROCEDURES:1. Clean cylinder head and gasket face.
2. When applicable, remove senders.
Cylinder Head Distortion:
Cylinder Head Height Check:
Check Cylinder Head For Distortion:
1. Use a steel ruler and feeler gauge.
- Distortion must not exceed 0.5 mm (0.02 in) longitudinally and 0.25 mm (0.O1 in) across cylinder head.
2. If distortion is greater, cylinder head should be machined.
CAUTION: If distortion is greater than 1.0 mm (0.04 in) longitudinally, or 0.5 mm (0.02 in) crosswise, cylinder head must be replaced.
3. Measure cylinder head height:
- new = 146.1 mm (5.752 in)
- Min = 145.6 mm (5.732 in)
Valve & Seat Inspection:
Clean/inspect Valves And Valve Seats:
1. Use a cutter to clean valve seats.
2, Remove carbon deposits from combustion chamber and valves.
3. Replace valve seats if they are fractured or show signs of excessive wear.
4. Clean and check spark plug threads for damage.
Valve Guide Wear Measurement:
Check Valve Guides For Wear:
1. Use magnetic stand and dial indicator.
2. Use new valves.
3. Lift valves 1-2 mm with finger when measuring.
Intake:
- Clearance, with new valve and new guide: 0.030-0.060 mm (0.0012-0.0024 in)
- Max. clearance, measured with new valve and old guide: 0.15 mm (0.006 in).
Exhaust:
- Clearance, with new valve and new guide: 0.060-0.090 mm (0.0024-0.0035 in)
- Max. clearance, measured with new valve and old guide: 0.15 mm (0.006 in).
Tappet Wear Inspection:
Check Tappets (Valve Depressors):
1. Check for scoring and other visible damages.
Valve Spring:
Valve Spring Length With Different Loadings:
Test Valve Springs:
1. Use a spring tester:
Length Load
mm(in) N (lbs)
L 45.5 (1.79) 0 (0)
L1 38.0 (1.50) 280-320 (62-70)
L2 27.5 (1.08) 702-782 (154-172)
Camshaft End Float:
Check Camshaft End Float:
1. Position camshaft in cylinder head.
2. Fit rear bearing cap.
3. Slide camshaft back and forth.
- End float should be 0.1-0.4 mm (0.OO4-0.O16 in). Use feeler gauge for measuring.
4. If end float is too large, replace rear bearing cap.
Timing Belt Tensioner:
Check Timing Belt Tensioner:
1. Bearing must not be worn.
2. Roller running face must not be damaged. If surface is damaged, both roller and timing belt must be replaced.