Page 207 - CTS - Mechanic Diesel - TP

MECHANIC DIESEL - CITS

EXERCISE 12.3 : Checking of positive crankcage

ventilation system

Objectives

At the end of this exercise you shall be able to
• inspect PCV hose
• inspect PCV valve.
Requirements

Tools/Instruments Equipments/Machines
• Trainee’s tool kit - 1 No. • Diesel Vehicle -1No.
• Digital multimeter - 1 No. Materials
• 12V battery - 1 No. • PCV solvent / lacquer thinner - as reqd.
• Scan tool - 1 No.
• Baniyan cloth - as reqd.
• PCV valve - 1 No.
• EVAP - 1 No.

Procedure

TASK 1: PCV HOSE Inspection
1 The PCV valve is usually located next to the valve cover of the engine, or in the intake manifold.
2 If you cannot identify it quickly, check with the work shop manual.
3 Check hoses for connection, leakage, clog and deterioration. Replace as necessary.

TASK 2: PCV valve inspection
1 Switch on the ignition and start the engine. With the engine idling, pinch the hose attached to the PCV valve
hard enough to shut off the supply of air through it. If the valve is working correctly, the idle speed should drop
enough for you to be able to hear the change.
2 Or Disconnect PCV valve from cylinder head cover and install plug to head cover hole. (Fig 1)

3 Run engine at idle speed.
4 Place your finger over end of PCV valve (1) as shown in Fig 2 to check for vacuum. (Fig 2)

Fig 1 Fig 2

5 If there is no vacuum, check for clogged valve.
6 Try cleaning it and to observe if it is working by with PCV solvent or lacquer thinners or immersing it in
carburetor cleaner. There should be no gummy deposits or discoloration on a clean valve.
7 If your PCV valve must be replace, buy a new valve, remove the old one, and insert the new one in its place.

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