Hyundai Elantra: Inspection - Cylinder Head. Repair procedures - Cylinder Head Assembly - Engine Mechanical System - Hyundai Elantra MD 2010-2018 Service manualHyundai Elantra: Inspection


Cylinder Head
1.
Inspect for flatness.

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

Flatness of cylinder head gasket surface:
Less than 0.05 mm (0.0020 in.) for total area
Less than 0.02 mm (0.0008 in.) for a section of 100 mm (3.9370 in.) X 100 mm (3.9370 in.)


Flatness of manifold mounting surface:
Less than 0.10 mm (0.0039 in.)

2.
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
1.
Inspect valve stems and valve guides.
(1)
Using a caliper gauge, measure the inside diameter of the valve guide.

Valve guide inner diameter
Intake: 5.500 ~ 5.512 mm (0.21654 ~ 0.21701 in.)
Exhaust: 5.500 ~ 5.512 mm (0.21654 ~ 0.21701 in.)

(2)
Using a micrometer, measure the diameter of the valve stem.

Valve stem outer diameter
Intake: 5.465 ~ 5.480 mm (0.21516 ~ 0.21575 in.)
Exhaust: 5.458 ~ 5.470 mm (0.21488 ~ 0.21535 in.)

(3)
Subtract the valve stem diameter measurement from the valve guide inside diameter measurement.
If the clearance is greater than specification, replace the valve or the cylinder head.

Valve stem-to-guide clearance
[Standard]
Intake : 0.020 ~ 0.047 mm (0.00079 ~ 0.00185 in.)
Exhaust : 0.030 ~ 0.054 mm (0.00118 ~ 0.00213 in.)

2.
Inspect the valves.
(1)
Check the valve is ground to the correct valve face angle.
(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 specification, replace the valve.

Margin
[Standard]
Intake: 1.30 mm (0.0512 in.)
Exhaust: 1.26 mm (0.0496 in.)

(4)
Check the valve length.

Valve length
[Standard]
Intake: 102.22 mm (4.0244 in.)
Exhaust: 104.04 mm (4.0961 in.)
[Limit]
Intake: 101.97 mm (4.0146 in.)
Exhaust: 103.79 mm (4.0862 in.)

(5)
Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, replace the valve.
3.
Inspect the valve seats and the valve guides.
(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.
4.
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.
If the free length is not as specified, replace the valve spring.

Valve spring
[Standard]
Free height: 45.93 mm (1.8083 in.)
Out-of-square : Less than 1.5

Camshaft
1.
Inspect the cam lobes.
Using a micrometer, measure the cam lobe height.
If the cam lobe height is less than specification, replace the camshaft.

Cam height
Intake: 39.0 mm (1.5354 in.)
Exhaust: 38.7 mm (1.5236 in.)

2.
Check the surface of the camshaft journal for wear.
If the journal is worn excessively, replace the camshaft.
3.
Inspect the camshaft journal clearance.
(1)
Clean the bearing caps and camshaft journals.
(2)
Place the camshafts on the cylinder head.
(3)
Lay a strip of plastigage across each of the camshaft journal.

(4)
Install the bearing caps and tighten the bolts with specified torque.

Tightening torque
M6 bolts:
11.8 ~ 13.7 N.m (1.2 ~ 1.4 kgf.m, 8.7 ~ 10.1 lb-ft)
M8 bolts:
18.6 ~ 22.6 N.m (1.9 ~ 2.3 kgf.m, 13.7 ~ 16.6 lb-ft)

Do not turn the camshaft.
(5)
Remove the bearing caps.
(6)
Measure the plastigage at its widest point.
If the oil clearance is greater than specification, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.

Bearing oil clearance
Standard:
0.032 ~ 0.062 mm (0.00126 ~ 0.00244 in.)

4.
Inspect the camshaft end play.
(1)
Install the camshaft bearing caps.
(2)
Using a dial indicator, measure the end play while moving the camshaft back and forth.
If the end play is greater than specification, replace the camshaft.
If necessary, replace the bearing caps and cylinder head as a set

Camshaft end play
Standard:
0.10 ~ 0.19mm (0.0039 ~ 0.0075 in.)

(3)
Remove the camshafts.
CVVT (Continuous Variable Valve Timing) Assembly
1.
Inspect CVVT assembly.
(1)
Fix the camshaft using a vise.
Be careful not to damage the cam lobe and journal.
(2)
Check that the CVVT assembly will not turn.
(3)
Apply vinyl tape to the retard hole like the one indicated by the arrow in the illustration.
Verify that the tape holds and put air through the port of the camshaft.

(4)
Wind tape around the tip of the air gun and apply air of approx. 150 kPa (1.5 kgf/cm², 21 psi) to the port of the camshaft.
Perform this in order to release the lock pin for the maximum delay angle locking.
Wrap around it with a shop rag and the likes to prevent oil from splashing.
(5)
With air applied, as in step (3), turn the CVVT assembly to the advance angle side (the arrow marked direction in the illustration) with your hand.
Depending on the air pressure, the CVVT assembly will turn to the advance side without applying force by hand. Also, under the condition that the pressure can be hardly applied because of the air leakage from the port, there may be the case that the lock pin could be hardly released.

(6)
Turn the CVVT assembly back and forth and check the movable range and that there is no disturbance.

Standard:
Should move smoothly in a range from about
25.0 (Intake) / 20.0 (Exhaust)

(7)
Turn the intake CVVT assembly with your hand and lock it at the maximum retard angle position (counter clockwise).
(8)
Turn the exhaust CVVT assembly with your hand and lock it at the maximum advance angle position (clockwise).
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 doesnt 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.
Faulty HLA
Remove the cylinder head cover and press HLA down by hand.
If it moves, replace the HLA.


    Disassembly
    Identify, valves and valve springs as they are removed so that each item can be reinstalled in its original position. ...

    Reassembly
    Thoroughly clean all parts to be assembled. Before installing ...