13666806

Inspection

Cylinder Head

Inspect for flatness.

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

Flatness of cylinder head gasket surface

Standard : Less than 0.05 mm (0.0020 in)

Less than 0.02 mm (0.0008 in) / 100 x 100

Flatness of manifold gasket surface

Standard : Less than 0.1 mm (0.0039 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 valve stems and valve guides.

(1)

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

Valve guide I.D.

Intake / Exhaust :

5.500 ~ 5.512 mm (0.2165 ~0.2170 in)

(2)

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

Valve stem O.D.

Intake : 5.465 ~ 5.480 mm ( 0.2151 ~ 0.2157 in)

Exhaust : 5.448 ~ 5.460 mm (0.2144 ~ 0.2149 in)

(3)

Subtract the valve stem diameter measurement from the valve guide inside diameter measurement.

Valve stem-to-guide clearance

Intake : 0.020 ~ 0.047 mm (0.00078 ~ 0.00185 in)

Exhaust : 0.040 ~ 0.064 mm (0.00157 ~ 0.00251 in)

Inspect valves.

(1)

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

Valve face angle :

Intake/Exhaust : 45.25˚ ~ 45.75˚

(2)

Check that the surface of the valve for wear. If the valve face is worn, replace the valve.

(3)

Check the valve head margin thickness. If the margin thickness is less than minimum, replace the valve.

Margin

Intake : 1.4~ 1.6 mm (0.0551 ~ 0.0629 in)

Exhaust : 1.65 ~ 1.85 mm (0.0649 ~ 0.0728 in)

(4)

Check the valve length.

Length

Intake : 100.94 mm (3.9740 in)

Exhaust : 101.09 mm (3.9799 in)

(5)

Check the surface of the valve stem tip for wear. If the valve stem tip is worn, replace the valve.

Inspect 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 cylinder head.

(2)

Before reconditioning the seat, check the valve guide for wear. If the valve guide is worn, replace cylinder head.

(3)

Recondition the valve seat with a valve seat grinder or cutter. The valve seat contact width should be within specifications and centered on the valve face.

Valve seat contact width :

Intake : 0.85 ~ 1.15 mm ( 0.0334 ~ 0.0452 in)

Exhaust : 1.35 ~ 1.65 mm (0.0531 ~ 0.0649 in)

Valve seat angle :

Intake / Exhaust : 44.75˚ ~ 45.10˚

Inspect valve springs.

(1)

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

(2)

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

Valve spring

Free height : 47.9mm (1.8858in)

Out-of-square : 1.5˚ (MAX)

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
1. Temporary noise when starting a cold engine	Normal	This noise will disappear after the oil in the engine reaches the normal pressure.
2. 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 step 7 below.
3. Continuous noise when the engine is first started after rebuilding cylinder head.	Insufficient oil in cylinder head oil gallery.
4. 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.Insufficient oil in the HLA.
5. Continuous noise when the engine is running after changing the HLA.		Do not run engine at a speed higher than 3000 rpm, as this may damage the HLA.
6. 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.
7. Noise continues for more than 15 minutes.	Low oil pressure.	Check oil pressure and oil supply system of each part of engine.
7. 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. Be careful with the hot HLAS.