Kia Carens: Cylinder Head Assembly / CVVT & Camshaft Description and operation

Kia Carens RP (2013-2018) Service Manual / Engine Mechanical System / Cylinder Head Assembly / CVVT & Camshaft Description and operation

Description

Continuous Variable Valve Timing (CVVT) system advances or retards the valve timing of the intake and exhaust valve in accordance with the ECM control signal which is calculated by the engine speed and load.

By controlling CVVT, the valve over-lap or under-lap occurs, which makes better fuel economy and reduces exhaust gases (NOx, HC) and improves engine performance through reduction of pumping loss, internal EGR effect, improvement of combustion stability, improvement of volumetric efficiency, and increase of expansion work.

This system consist of

–	the CVVT Oil Control Valve (OCV) which supplies the engine oil to the cam phaser or runs out the engine oil from the cam phaser in accordance with the ECM PWM (Pulse With Modulation) control signal,

–	the CVVT Oil Temperature Sensor (OTS) which measures the engine oil temperature,

–	and the Cam Phaser which varies the cam phase by using the hydraulic force of the engine oil.

The engine oil getting out of the CVVT oil control valve varies the cam phase in the direction (Intake Advance/Exhaust Retard) or opposite direction (Intake Retard/Exhaust Advance) of the engine rotation by rotating the rotor connected with the camshaft inside the cam phaser.

Operation Principle

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.

[CVVT System Mode]

(1) Low Speed / Low Load	(2) Part Load

(3) Low Speed / High Load	(4) High Speed / High Load

Driving Condition	Exhaust Valve		Intake Valve
Driving Condition	Valve Timing	Effect	Valve Timing	Effect
(1) Low Speed /Low Load	Completely Advance	* Valve Under-lap * Improvement of combustion stability	Completely Retard	* Valve Under-lap * Improvement of combustion stability
(2) Part Load	Retard	* Increase of expansion work * Reduction of pumping loss * Reduction of HC	Retard	* Reduction of pumping loss
(3) Low Speed /High Load	Retard	* Increase of expansion work	Advance	* Prevention of intake back flow (Improvement of volumetric efficiency)
(4) High Speed /High Load	Advance	* Reduction of pumping loss	Retard	* Improvement of volumetric efficiency

CVVT & Camshaft Components and components location

Components 1. Exhaust camshaft 2. Intake camshaft 3. Exhaust CVVT 4. Intake CVVT 5. Camshaft bearing cap 6. Camshaft front bearing cap 7. O-rin ...

CVVT & Camshaft Repair procedures

Removal 1. Remove the cylinder head cover. (Refer to Cylinder Head Assembly - "Cylinder Head Cover") 2. Turn the cran ...

Other information:

Kia Carens RP (2013-2018) Owners Manual: Vehicle stability management (VSM)

This system provides further enhancements to vehicle stability and steering responses when a vehicle is driving on a slippery road or a vehicle detected changes in coefficient of friction between right wheels and left wheels when braking. VSM operation When the VSM is operating: ESC (Electronic ...

Kia Carens RP (2013-2018) Owners Manual: Manual type

To adjust the headlight beam level according to the number of the passengers and the loading weight in the luggage area, turn the beam leveling switch. The higher the number of the switch is positioned, the lower the headlight beam level. Always keep the headlight beam at the proper leveling posi ...