Hyundai Elantra Owners and Service Manuals

Hyundai Elantra: Cylinder Head Assembly / CVVT & Camshaft

Hyundai Elantra (CN7) 2021-2025 Service Manual / Engine Mechanical System / Cylinder Head Assembly / CVVT & Camshaft

Repair procedures
Removal
1.
Disconnect the battery negative terminal.
2.
Remove the cylinder head cover.
(Refer to Cylinder Head Assembly - "Cylinder Head Cover")
3.
Turn the crankshaft damper pulley so that No. 1 piston is at top dead center.
(1)
Turn the crankshaft damper pulley and align its groove with the timing mark on the timing chain cover

(2)
Check the timing chain, be sure that the timing mark (A) of each sprocket is matched with the timing mark (B) (color link) of the timing chain.
If not, turn the crankshaft damper pulley by one revolution (360°).
[Intake CVVT]

[Exhaust CVVT]

4.
Remove the intake and exhaust variable force solenoid (VFS) valves (A).

5.
Remove the cam to cam guide (A).

6.
Remove the fuel pump bracket (A).

7.
Remove the camshaft front bearing cap (A) and camshaft bearing caps (B).

8.
Loosen the service hole bolt (A).

9.
Install the jack to the edge of oil pan
10.
Lift the engine using the jack to obtain space.
11.
Release the lock by putting down rachet plate (B) of timing chain tensioner with using back of tiny awl (A).

12.
Remove the intake oil control valve (OCV) & center bolt (A).

   
•
To prevent impurities from entering intake oil control valve (OCV) & center bolt, wear rubber gloves.
•
Intake oil control valve (OCV) and center bolt, hold the hexagonal portion on the camshaft with a wrench to prevent the camshaft from rotating.

13.
Remove the exhaust oil control valve (OCV) and center bolt (A).

   
•
To prevent impurities from entering exhaust oil control valve (OCV) & center bolt, wear rubber gloves.
•
When removing the exhaust oil control valve (OCV) and center bolt, hold the hexagonal portion on the camshaft with a wrench to prevent the camshaft from rotating.

14.
Remove the CVVD assembly.
   
•
After removing the CVVD unit, make sure that the parts such as lifter, cam, etc are not separated.
•
Ensure that the CVVD components are not damaged.
When Using the CVVD fixture
(1)
Install the CVVD fixture (A) over the CVVD assembly.

(2)
Remove the CVVD assembly.

When not using the CVVD fixture
(1)
Remove the CVVD assembly.

15.
Remove the Intake CVVT (A).

16.
Remove the exhaust camshaft (A).

17.
Remove the exhaust CVVT (A).

   
•
Fasten the timing chain to the engine hanger with a cable tie or strap not to allow the timing chain to fall down when removing the intake and exhaust CVVT & camshaft.

Inspection
Camshaft
1.
Measure the height of the cam.
Check the surface of the cam lob for wear and tear. If necessary, replace the camshaft.
Cam height
Intake : 37.33 mm (1.4697 in.)
Exhaust : 37.44 mm (1.474 in.)

2.
Inspect the camshaft journal clearance.
(1)
Clean the camshaft journals and bearing caps.
(2)
Place the camshafts on the cam carrier.
(3)
Lay a strip of plasticgauge across each of the camshaft journals.

(4)
Install the camshaft front bearing cap (A) and camshaft bearing caps (B).

1)
Install the camshaft front bearing cap and camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

2)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

3)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

4)
Install the camshaft front bearing cap and camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

5)
Install the camshaft front bearing cap and camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6 lb-ft)

6)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
11.8 - 13.7 N.m (1.2 - 1.4 kgf.m, 8.7 - 10.1 lb-ft)

7)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
11.8 - 13.7 N.m (1.2 - 1.4 kgf.m, 8.7 - 10.1 lb-ft)

(5)
Remove the camshaft bearing caps.
(6)
Measure the plasticgauge at the widest point.
If the oil clearance is greater than the specification, replace the camshaft.
If necessary, replace the bearing caps and cam carrier.
Cam height
No.1 : 0.040 - 0.071 mm (0.0016 - 0.0028 in.)
No.2, 3, 4, 5 : 0.035 - 0.065 mm (0.0014 - 0.0026 in.)

(7)
Remove the plasticgauge.
(8)
Remove the camshafts.
3.
Inspect the camshaft end play.
(1)
Install the camshafts.
(2)
Measure the end play while moving the camshaft back and forth using a dial gauge.
Camshaft end play
Standard value : 0.10 - 0.19 mm (0.0039 - 0.0075 in.)

If the end play is greater than the specification, replace the camshaft. If necessary, replace the cylinder head.
Installation
1.
Install the intake CVVT (A).

2.
Install the CVVD assembly (A).

   
•
After installing the CVVD, check whether the swing arm is separated or is installed correctly.
•
When installing the intake camshaft, spray the engine oil to the camshaft journal installing part (A) of the cam carrier.
The amount of application should be enough to flow down both the front and back sides when it is applied to the center.
•
For installation, the timing mark (A) of the intake CVVT and the timing chain mark (B) should be matched.

   
•
During the installation, there should be no artifical rotation or movement of the guide bracket and control shaft.
•
When removing the CVVD fixing jig, be sure to securely tighten the M6 bolts.
•
If CVVD fixing jig is available, be sure to work by using it.
When Using the CVVD fixture
1. When installing the CVVD assembly mounting bolts (M6), tighten sequence shown.
Tightening torque :
1ST
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)
2nd
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

2. Remove the CVVD fixture (A).

3. Provisionally tighten the CVVD assembly mounting bolts (M8) in sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

4. Remove the CVVD assembly mounting bolts (M6) (A).

5. Provisionally tighten the CVVD assembly mounting bolts (M6) in sequence shown below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

6. Tighten the CVVD assembly mounting bolts (M8) in sequence shown below.
Tightening torque :
18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6 lb-ft)

7. Tighten the CVVD assembly mounting bolts (M6) in sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

8. Measure the clearance between the control shaft bearing cap and the end of control shaft using a clearance gauge.
Clearance : 0.0 - 0.05 mm (0.0 - 0.002 in.)

When not using the CVVD fixture
1. Provisionally tighten the CVVD assembly mounting bolts (M6) in sequence shown below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

2. Provisionally tighten the CVVD assembly mounting bolts (M8) in sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

3. Tighten the CVVD assembly mounting bolts (M8) in sequence shown below.
Tightening torque :
18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6 lb-ft)

4. Tighten the CVVD assembly mounting bolts (M6) in sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

5. Release the torque of control shaft bearing cap bolt (A).

6. Push the control shaft bearing cap as close as possible in the direction of the arrow.

7. Install the control shaft bearing cap mounting bolts (A).
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

8. Measure the clearance between the control shaft bearing cap and the end of control shaft using a clearance gauge.
Clearance : 0.0 - 0.05 mm (0.0 - 0.002 in.)

3.
Install the intake OCV & center bolt (A).
Tightening torque :
22.6 - 26.5 N.m (2.3 - 2.7 kgf.m, 16.6 - 19.5 lb-ft) + 32 - 36°

   
•
To prevent impurities from entering intake oil control valve (OCV) & center bolt, wear rubber gloves.
•
intake oil control valve (OCV) and center bolt, hold the hexagonal portion on the camshaft with a wrench to prevent the camshaft from rotating.

4.
Compress the timing chain tensioner piston.
(1)
With a pry bar (A), compress the timing chain tensioner piston (B).

(2)
With a thin gimlet (A), raise the ratchet plate (B) of the timing chain tensioner and fix the piston.

   
•
Do not remove the pick (A).
5.
Install the exhaust CVVT (A).

   
•
When installing the timing chain, be sure that the timing mark (A) of each sprocket is matched with the timing mark (B) (color link) of the timing chain.
[Exhaust CVVT Timing Mark]

6.
Install the exhaust camshaft (A).

   
•
After installing exhaust camshaft, check whether the swing arm is separated or is installed correctly.
•
When installing the exhaust camshaft, spray the engine oil to the camshaft journal installing part of the cam carrier.
The amount of application should be enough to flow down both the front and back sides when it is applied to the center..
7.
Install the exhaust oil control valve (OCV) and center bolt (A).
Tightening torque :
22.6 - 26.5 N.m (2.3 - 2.7 kgf.m, 16.6 - 19.5 lb-ft) + 32 - 36°

   
•
To prevent impurities from entering exhaust oil control valve (OCV) & center bolt, wear rubber gloves.
•
When installing the exhaust oil control valve (OCV) and center bolt, hold the hexagonal portion on the camshaft with a wrench to prevent the camshaft from rotating.

8.
Install the camshaft front bearing cap (A) and camshaft bearing caps (B).

   
•
If there is enough engine oil on the camshaft front bearing cap and camshaft bearing cap installing bolt and bolt hole, tighten to the minimum required tightening torque.
•
Apply engine oil the upper part of the intake / exhaust camshaft journal, then install the camshaft front bearing cap and camshaft bearing cap. The amount of application should be enough to flow down both the front and back sides when it is applied to the center.
1)
Install the camshaft front bearing cap and camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

2)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

3)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)

4)
Install the camshaft front bearing cap and camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

5)
Install the camshaft front bearing cap and camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6 lb-ft)

6)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
11.8 - 13.7 N.m (1.2 - 1.4 kgf.m, 8.7 - 10.1 lb-ft)

7)
Install the camshaft bearing cap installing bolt with direction from back of engine to the front of engine according to the procedure at down below.
Tightening torque :
11.8 - 13.7 N.m (1.2 - 1.4 kgf.m, 8.7 - 10.1 lb-ft)

9.
Remove the fine gimlets (A) that hold the timing chain tensioner.

10.
When installing the timing chain, be sure that the timing mark (A) of each sprocket is matched with the timing mark (B) (color link) of the timing chain.
[Intake CVVT Timing Mark]

[Exhaust CVVT Timing Mark]

11.
Install the fuel pump bracket (A).
Tightening torque :
18.6 - 23.5 N.m (1.9 - 2.4 kgf.m, 13.7 - 17.4 lb-ft)

12.
Install the cam to cam guide (A).
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

13.
Install the intake and exhaust variable force solenoid (VFS) valves (A).
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)

14.
Install the cylinder head cover.
(Refer to Cylinder Head Assembly - "Cylinder Head Cover")

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