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Inspection

Cylinder Head

Inspect for flatness.

Using a precision straight edge and feeler gauge, measure the surface the contacting the cylinder block and the manifolds for warpage.

Flatness of cylinder head gasket surface :

Less than 0.03 mm (0.0012 in) for width

Less than 0.09 mm (0.0035 in) for lengthh

Less than 0.012 mm (0.0005 in) for a section of 50 mm x 50 mm (1.9685 in x 1.9685 in)

Flatness of manifold mating surface :

Less than 0.025 mm (0.0010 in) for width

Less than 0.160 mm (0.0063 in) for length

Less than 0.013 mm (0.0005 in) for a section of 25 mm x 25 mm (0.9843 in x 0.9843 in)

Inspect for cracks.

Check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.

If cracked, replace the cylinder head.

Valve And Valve Spring

Inspect the valve stems and valve guides.

(1)

Using a caliper gauge, measure the inner diameter of valve guide.

Valve guide inner diameter :

5.975 ~6.000 mm (0.2352 ~ 0.2362 in)

(2)

Using a micrometer, measure the outer diameter of valve stem.

Valve stem outer diameter

Intake : 5.933 ~ 5.953 mm (0.2336 ~ 0.2344 in)

Exhaust : 5.905 ~ 5.925 mm (0.2325 ~ 0.2333 in)

(3)

Subtract the valve stem outer diameter measurement from the valve guide inner diameter measurement.

Valve stem- to-guide clearance

Intake : 0.022 ~ 0.067 mm (0.0009 ~ 0.0026 in)

Exhaust : 0.050 ~ 0.095 mm (0.0020 ~ 0.0037 in)

If the clearance is greater than specification, replace the valve or the cylinder head.

Inspect the valves.

(1)

Check the valve is ground to the correct valve face angle.

(2)

Check that the surface of valve for wear.

If the valve face is worn, replace the valve.

(3)

Check the valve head margin thickness.

Margin

Intake : 1.25 mm (0.0492 in)

Exhaust : 1.25 mm (0.0492 in)

If the margin thickness is less than specification, replace the valve.

(4)

Check the valve length.

Length

Intake : 108.3 mm (4.2638 in)

Exhaust : 108.2 mm (4.2598 in)

(5)

Check the surface of valve stem tip for wear.

If the valve stem tip is worn, replace the valve.

Inspect the valve seats.

(1)

Check the valve seat for evidence of overheating and improper contact with the valve face.

If the valve seat is worn, replace the cylinder head.

(2)

Check the valve guide for wear.

If the valve guide is worn, replace the cylinder head.

Inspect the valve springs.

(1)

Using a steel square, measure the out-of-square of valve spring.

(2)

Using a vernier calipers, measure the free length of valve spring.

(3)

If the loads is not as specified, replace the valve spring.

Valve spring

Standard

Free height : 44.0 mm (1.7323 in)

Load : 19.9±1.0 kg (44±21 lb) / 36.6 mm (1.4409 in),

44.1±2.2 kg (97±5 lb) / 27.6 mm (1.0866 in)

Out of square : Less than 1.5° / 1.15 mm (0.0453 in)

HLA (Hydraulic Lash Adjuster)

With the HLA filled with engine oil, hold A and press B by hand.

If B moves, replace the HLA.

Problem	Possible cause	Action
Temporary noise when starting a cold engine	Normal	This noise will disappear after the oil in the engine reaches the normal pressure.
Continuous noise when the engine is started after parking more than 48 hours	Oil leakage of the high pressure chamber on the HLA, allowing air to get in	Noise will disappear within 15 minutes when engine runs at 2000-3000 rpm. If it doesn’t disappear, refer to the lowest step. note Do not run engine at a speed higher than 3000 rpm, as this may damage the HLA.
Continuous noise when the engine is first started after rebuilding cylinder head	Insufficient oil in cylinder head oil gallery
Continuous noise when the engine is started after excessively cranking the engine by the starter motor or band	Oil leakage of the high-pressure chamber in the HLA, allowing air to get in and insufficient oil in the HLA
Continuous noise when the engine is running after changing the HLA
Continuous noise during idle after high engine speed	Engine oil level too high or too low	Check oil level. Drain or add oil as necessary.
	Excessive amount of air in the oil at high engine speed	Check oil supply system.
	Deteriorated oil	Check oil quality. If deteriorated, replace with specified type.
Noise continues for more than 15 minutes	Low oil pressure	Check oil pressure and oil supply system of each part of engine.
Noise continues for more than 15 minutes	Faulty HLA	Remove the cylinder head cover and press HLA down by hand. If it moves, replace the HLA. caution Be careful handling the hot HLA.