Hyundai Accent Manuals

Hyundai Accent: Inspection - Cylinder Head. Repair procedures - Cylinder Head Assembly - Engine Mechanical SystemHyundai Accent: 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
Standard :
Less than 0.05mm (0.0020in) for total area
Less than 0.02mm (0.0008in) for a section of 100mm (3.9370in) X 100mm (3.9370in)

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

Valve guide inner diameter :
5.500 ~ 5.512mm (0.2165 ~ 0.2170in)

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

Valve stem outer diameter
Intake : 5.465 ~ 5.480mm (0.2152 ~ 0.2157in)
Exhaust : 5.458 ~ 5.470mm (0.2149 ~ 0.2154in)

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

Valve stem- to-guide clearance
Intake : 0.020 ~ 0.047mm (0.0008 ~ 0.0019in)
Exhaust : 0.030 ~ 0.054mm (0.0012 ~ 0.0021in)

If the clearance is greater than specification, replace the valve or the cylinder head.
Inspect the valves.
Check the valve is ground to the correct valve face angle.
Check that the surface of valve for wear.
If the valve face is worn, replace the valve.
Check the valve head margin thickness.
If the margin thickness is less than minimum, replace the valve.

Intake : 1.10mm (0.0433in)
Exhaust : 1.26mm (0.0496in)

Check the length of valve.

Valve length
Intake : 93.15mm (3.6673 in)
Exhaust : 92.60mm (3.6457 in)

Check the surface of valve stem tip for wear.
If the valve stem tip is worn, replace the valve.
Inspect the valve seats.
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.
Check the valve guide for wear. If the valve guide is worn, replace the cylinder head.
Inspect the valve springs.
Using a steel square, measure the out-of-square of valve spring.
Using a vernier calipers, measure the free length of valve spring.

Valve spring
Free height : 45.1mm (1.7756in)
Out of square : Less than 1.5°

Inspect the cam height.
Using a micrometer, measure the cam height.

Cam height
Intake : 44.15mm (1.7382in)
Exhaust : 43.55mm (1.7146in)

If the cam lobe height is less than specified, replace the camshaft.
Check the cranshaft journal for wear.
If the journal is worn excessively, replace the camshaft.
Inspect the camshaft journal clearance.
Clean the bearing caps and camshaft journals.
Place the camshafts on the cylinder head.
Lay a strip of plastigage across each of the camshaft journal.

Install the bearing caps and tighten the bolts with specified torque.

Tightening torque
1st step
M6 bolt :
5.9 N.m (0.6 kgf.m, 4.3 lb-ft)
M8 bolt :
9.8 N.m (1.0 kgf.m, 7.2 lb-ft)
2nd step
M6 bolts :
11.8 ~ 12.7N.m (1.2 ~ 1.3kgf.m, 8.7 ~ 9.4lb-ft)
M8 bolts :
18.6 ~ 22.6N.m (1.9 ~ 2.3kgf.m, 13.7 ~ 16.6lb-ft)

Do not turn the camshaft.
Remove the bearing caps.
Measure the plastigage at its widest point.

Bearing oil clearance
Standard : 0.027 ~ 0.058mm (0.0011 ~ 0.0023in)
Limit : 0.1mm ( 0.0039in)

If the oil clearance is greater than specified, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
Inspect the camshaft end play.
Install the camshafts.
Using a dial indicator, measure the end play while moving the camshaft back and forth.

Camshaft end play
Standard : 0.1 ~ 0.2mm (0.0039 ~ 0.0079in)

If the end play is greater than specified, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
Remove the camshafts.
Continuous Variable Valve Timing (CVVT) Assembly
Inspect the Continuous variable valve timing (CVVT) assembly.
Fix the Continuous variable valve timing (CVVT ) with its camshaft in a vice.
Check that the CVVT assembly will not turn. If it is not turned, it is in normal condition.
Apply vinyl tape to all the parts except the one hole.
Using an air gun, apply the pressure, 147.10kpa (1.5kg/cm², 21.33psi) in the hole. This makes the lock pin in maximum retarded state released.
Wrap around it with a shop rag, because the oil can splash out..
After releasing the pin, you can turn the CVVT assembly for advance by hand.
If there was too much air leakage, the pin can not be released.
Under the condition of 3), turn the CVVT assembly to the advance angle side with your hand.
Depending on the air pressure, the CVVT assembly will turn to the advance side.
Also, if the air pressure that wasapplied was insufficient because of the air leakage from the port, the lock pin may not release properly.
Except the position where the lock pin meets at the maximum delay angle, let the CVVT assembly turn back and forth and check the movable range and that there is no interference.

Standard : Movable smoothly in the range about 25°

Turn the CVVT assembly with your hand counterclockwise and lock it at the maximum delay angle position.

Identify MLA(Mechanical lash adjuster), valves, valve springs as they are removed so that each item can be reinstalled in ...

• Thoroughly clean all parts to be assembled. • ...

See also:

Before starting
Close and lock all doors. Position the seat so that all controls are easily reached. Adjust the inside and outside rearview mirrors. Be sure that all lights work. Check all gauges. Check ...

1. Measure the output voltage between the terminal of the wheel speed sensor and the body ground. ...

1. Check signal waveform of CKPS and CMPS using a GDS. Specification: Refer to “Waveform” ...

Hyundai Accent Manuals

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