Page 78 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

EXERCISE 2.26: Practice on checking and setting variable

valve timing

Objectives

At the end of this exercise you shall be able to
• check cam shaft drive parts
• check variable valve timing components
• check operation of variable valve timing mechanism.

Requirements

Tools/Equipments/Materials

• Trainees tool kit • Scan tool
• Timing gear puller • Timing belt/chain
• Torque wrench • Engine oil
• Socket set • Spare VVT solenoid valve
• Digital multimeter • Timing gears/sockets
• Engine with VVT mechanism
• Vehicle with VVT mechanism

Procedure

• Remove the alternator drive belt from the crank shaft pulley.
• Lock the flywheel.
• Remove the crank shaft pulley.

• Remove the timing belt cover.
TASK 1: Check the cam shaft drive parts

1 Check the condition of timing belt or chain. If excessive slackness on chain/belt having
cracks, missing teeth and worn out condition is found, replace them.
2 Visually check the condition of gears and drive sprocket. If any war found on teeth or hub, replace the parts.

3 Check the chain or belt tensioner. Replace if necessary.

TASK 2: Check variable valve timing components

1 Inspect the variable valve timing components (VVT assembly on cam shaft hub) for any leakage, cracks and
damage on mountings of VVT controller assembly.
2 If any defects found, replace VVT controller assembly.

Note: after completion of task 1 & 2, reassemble the removed parts of engine.

TASK 3: Check the operation of variable valve timing mechanism
1 Start the engine/vehicle and check the MIL lamp.

2 If you found the following problems
• Rough idling/failure to start

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CITS : Automotive - Mechanic Diesel - Exercise 2.25