Hyundai i-30: Cylinder Head Assembly / CVVT & Camshaft
Description and operation
The continuous variable valve timing (CVVT) system advances or retards the opening
of an intake or exhaust valve according to the ECM signals that are determined
based on engine RPM and load.
Due to CVVT control, a valve overlap or underlap occurs between the intake valve
and exhaust valve, resulting in the reduction of pumping loss, recirculation
of exhaust gas, improvement in combustion stability and volumetric efficiency,
and increase in expansion work. This in turn improves fuel efficiency and engine
performance and reduces emission gases (NOx and HC).
The CVVT system is composed of a CVVT oil control valve (OCV), CVVT oil temperature
sensor (OTS), and a cam phaser; The OCV receives a pulse width modulation signal
from the ECM and controls the flow of oil to supply oil to the cam phaser, the
OTS measures the temperature of the engine oil, and the cam phaser changes the
phase of the camshaft using the engine oil pressure.
The oil supplied from the CVVT OCV rotates the rotor connected to the camshaft
inside the cam phaser. The rotor, in turn, rotates the camshaft in the direction
of engine rotation (intake advanced / exhaust retarded) or in the opposite direction
of engine rotation (intake retarded / exhaust advanced) to change the phase
angle of the cam.
The CVVT has the mechanism rotating the rotor vane with hydraulic force generated
by the engine oil supplied to the advance or retard chamber in accordance with
the CVVT oil control valve control.
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A separate solenoid valve is installed on the chain cover in
the intake side for closing and releasing a separate lock pin.
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1. |
Intake CVVT
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2. |
Exhaust CVVT
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(1) Low Speed / Low Load
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(2) Part Load
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(3) Low Speed / High Load
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(4) High Speed / High Load
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Driving
Condition
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Exhaust Valve
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Intake Valve
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Valve
Timing
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Effect
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Valve
Timing
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Effect
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(1) Low Speed
/Low Load
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Completely
Advance
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* Valve Under-lap
* Improvement of combustion stability
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Middle
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* Valve Under-lap
* Improvement of combustion stability
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(2) Part Load
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Retard
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* Reduction of HC
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Retard
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* Delays the closing time of intake valve to reduce pumping loss
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(3) Low Speed
/High Load
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Completely Advance
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* Reduction of pumping loss
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Advance
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* Improvement of volumetric efficiency
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(4) High Speed
/High Load
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Completely Advance
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* Reduction of pumping loss
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Advance
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* Improvement of volumetric efficiency
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Repair procedures
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Use fender covers to avoid damaging painted surfaces.
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•
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To avoid damage, unplug the wiring connectors carefully while
holding the connector portion.
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•
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Mark all wiring and hoses to avoid misconnection.
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•
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Turn the crankshaft pulley so that the No. 1 piston is at top
dead center.
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1. |
Remove the cylinder head cover.
(Refer to Cylinder Head Assembly - "Cylinder Head Cover")
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2. |
Turn the crankshaft damper pulley and align its groove with the timing
mark of the timing chain cover to set the piston of No.1 cylinder to
the top dead center on compression stroke.
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3. |
Remove the timing chain cover.
(Refer to Timing System - "Timing Chain Cover")
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4. |
Before removing the timing chain, mark the timing chain with an identification
based on the location of the sprocket (CVVT) because the identification
mark on the chain for TDC (Top Dead Center) can be erased.
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5. |
Remove the timing chain.
(Refer to Timing System - "Timing Chain")
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6. |
Remove the intake CVVT assembly (A) and exhaust CVVT assembly (B).
• |
To prevent impurities from entering OCV & center bolt.
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• |
Do not use any dropped OCV & center bolt.
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• |
When removing and installing the intake/exhaust OCV
& Center bolt, hold the camshaft with a wrench to prevent
the camshaft from rotating.
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7. |
Remove the front camshaft bearing cap (A) and the camshaft bearing caps
(B).
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8. |
Remove the CVVD assembly.
• |
After removing the CVVD unit, make sure that the parts
such as lifter, cam, etc are not separated.
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• |
Ensure that the CVVD components are not damaged.
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Use the CVVD fixture
(1) |
Install the CVVD fixture (A) over the CVVD assembly.
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(2) |
Remove the CVVD assembly.
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Do not use the CVVD fixture
(1) |
Remove the CVVD assembly.
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9. |
Remove the exhaust camshaft (A).
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Camshaft
1. |
Inspect the cam lobes.
Using a micrometer, measure the cam lobe height.
Cam height
Intake : 36.125 mm (1.4222 in.)
Exhaust : 35.73 mm (1.4067 in)
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If the cam lobe height is less than standard, replace the camshaft.
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2. |
Check the surface of the camshaft journal for wear.
If the journal is worn excessively, replace the camshaft.
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3. |
Inspect the camshaft journal clearance.
(1) |
Clean the bearing caps and camshaft journals.
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(2) |
Place the camshafts on the cylinder head.
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(3) |
Lay a strip of plastigage across each of the camshaft journals.
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(4) |
Install the front camshaft bearing cap and the camshaft bearing
caps as following method with specified torque.
Tightening torque
A(M8) : 18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6
lb-ft)
B(M6) : 11.7 - 13.7 N.m (1.2 -1.4 kgf.m, 8.6 - 10.1
IB-ft)
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• |
Do not turn the camshaft.
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• |
When cam caps are installed, the arrows on top
of caps must point outward from the engine.
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(5) |
Remove the bearing caps.
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(6) |
Measure the plastigage at its widest point.
Bearing oil clearance
Standard
Intake :
0.032 - 0.062 mm (0.0013 - 0.0024 in) (No.1,2,3,4,5
journal)
Exhaust :
0.032 - 0.062 mm (0.0013 - 0.0024 in) (No.1,2,3,4,5
journal)
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If the oil clearance is greater than maximum, replace the camshaft.
If necessary, replace cylinder head.
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(7) |
Completely remove the plastigage.
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(8) |
Remove the camshafts.
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4. |
Inspect the camshaft end play.
(1) |
Install the camshafts.
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(2) |
Install the front camshaft bearing cap and the camshaft bearing
caps as following method with specified torque.
Tightening torque
A(M8) : 18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6
lb-ft)
B(M6) : 11.7 - 13.7 N.m (1.2 -1.4 kgf.m, 8.6 - 10.1
IB-ft)
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• |
Do not turn the camshaft.
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• |
When cam caps are installed, arrows on the top
of caps must point to out side of engine.
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(3) |
Using a dial indicator, measure the end play while moving the
camshaft back and forth.
Camshaft end play
Intake : 0.1 - 0.2 mm (0.0039 - 0.0078 in)
Exhaust : 0.1 - 0.2 mm (0.0039 - 0.0078 in)
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If the end play is greater than maximum, replace the camshaft.
If necessary, replace cylinder head.
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(4) |
Remove the camshafts.
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1. |
Install the exhaust camshaft (A).
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2. |
Install the CVVD assembly (A).
• |
After installing the CVVD, check whether the swing arm
is separated or is installed correctly.
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• |
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.
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• |
For installation, the timing mark (A) of the intake
CVVT and the timing chain mark (B) should be matched.
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• |
During the installation, there should be no artifical
rotation or movement of the guide bracket and control
shaft.
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When removing the CVVD fixing jig, be sure to securely
tighten the M6 bolts.
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• |
If CVVD fixing jig is available, be sure to work by
using it.
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Use 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)
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2) |
Remove the CVVD fixture (A).
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3) |
Tighten the CVVD assembly mounting bolts (M8) according
to the tightening sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)
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4) |
Remove the CVVD assembly mounting bolts (M6) (A).
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5) |
Tighten the CVVD assembly mounting bolts (M6) according
to the tightening sequence shown below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)
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6) |
Tighten the CVVD assembly mounting bolts (M8) according
to the tightening sequence shown below.
Tightening torque :
18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6
lb-ft)
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7) |
Tighten the CVVD assembly mounting bolts (M6) according
to the tightening sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)
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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.)
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Do not use the CVVD fixture
1) |
Tighten the CVVD assembly mounting bolts (M6) according
to the tightening sequence shown below.
Tightening torque :
4.9 - 6.9 N.m (0.5 - 0.7 kgf.m, 3.6 - 5.1 lb-ft)
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2) |
Tighten the CVVD assembly mounting bolts (M8) according
to the tightening sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)
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|
3) |
Tighten the CVVD assembly mounting bolts (M8) according
to the tightening sequence shown below.
Tightening torque :
18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6
lb-ft)
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4) |
Tighten the CVVD assembly mounting bolts (M6) according
to the tightening sequence shown below.
Tightening torque :
9.8 - 11.8 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb-ft)
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5) |
Release the torque of control shaft bearing cap bolt
(A).
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6) |
Push the control shaft bearing cap as close as possible
in the direction of the arrow.
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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)
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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.)
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3. |
Install the intake CVVT assembly (A) and exhaust CVVT assembly (B).
Tightening torque :
Intake : 22.5 - 26.4 N.m (2.3 - 2.7 kgf.m, 16.6 - 19.5 lb-ft)
+ 28 - 32°
Exhaust : 22.5 - 26.4 N.m (2.3 - 2.7 kgf.m, 16.6 - 19.5 lb-ft)
+ 32 - 36°
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• |
To prevent impurities from entering OCV & center bolt.
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• |
Do not use any dropped OCV & center bolt.
|
• |
When removing and installing the intake/exhaust OCV
& Center bolt, hold the camshaft with a wrench to prevent
the camshaft from rotating.
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• |
When installing OCV & center bolt, temporarily install
by hand, and then fully install by using a tool.
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• |
When installing OCV & center bolt, install to the specified
tightening torque.
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• |
When installing OCV & center bolt, use the hand operated
tool and do not use the power tool or air tool to prevent
the part from getting damaged.
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4. |
Install the front camshaft bearing cap and the camshaft bearing caps
as following method with specified torque.
Tightening torque :
A(M8) : 18.6 - 22.6 N.m (1.9 - 2.3 kgf.m, 13.7 - 16.6 lb-ft)
B(M6) : 11.7 - 13.7 N.m (1.2 -1.4 kgf.m, 8.6 - 10.1 IB-ft)
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5. |
Install the other parts in the reverse order of removal.
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Components and components location
Components
1. Cylinder head
cover
2. Engine oil cap
3. Cylider head cover gasket
4...
Description and operation
Description
CVVD (Continuous Variable Valve Duration) System is a device to control the
optimum open and close timing according to the driving mode by changing the
valve opening section...
Other information:
➀ Cruise indicator
➁ Set speed
➂ Vehicle-to-vehicle distance
To see the SCC screen on the LCD
display in the cluster, select ASSIST
mode (). For more information,
refer to “LCD Display Modes” in
chapter 3.
The Smart Cruise Control System
allows you to program the vehicle to
maintain constant speed and minimum
distance between the vehicle
ahead...
WARNING
An Anti-Lock Braking System
(ABS) or an Electronic Stability
Control (ESC) system will not
prevent accidents due to
improper or dangerous driving
manoeuvres. Even though vehicle
control is improved during
emergency braking, always
maintain a safe distance
between you and objects ahead
of you...
Categories
Operating door locks from
outside the vehicle
Mechanical key
Turn the key toward the rear of the
vehicle to unlock and toward the front
of the vehicle to lock.
If you lock/unlock the driver's door
with a key, a driver’s door will
lock/unlock automatically.
read more