Test the cylinder compression of an engine

 PROCEDURE 

1} Check the water level in the radiator and top up if needed. 

2} Check the engine oil level and top up, if needed. 

3} Check the electrolyte level in the battery and top up with distilled water if needed.

 4} Insert the key in the main switch  and press fully in and turn the key to the `ON' position.  

5} Observe the ammeter  on the instrument pannel. The indicator of the meter will show slightly on the discharge side (-ve side) of the meter and the ignition bulb  will glow red and also the oil pressure indicator  will glow.

 6} Observe the fuel gauge . The indicator indicates the fuel in the tank from empty to full. Note down the quantity of fuel in the fuel tank

. 7} Depress the accelerator lever fully.

 8} Press the starter `button' or turn the ignition key further and crank the engine

9} Release the starter button /key as soon as the engine has started. 

                  Once the engine starts do not touch the starter switch. 

10} If the engine does not start immediately do not keep the starter button pressed or key turned beyond   10 seconds otherwise, the battery will get discharged or the teeth of the flywheel ring and pinion will get damaged or the self-starter motor will get damaged.

 11} Raise the engine r.p.m. steadily and allow the engine to warm up.

 12} Observe the ammeter. The indicator on the positive side shows charging of the battery. 

13} Observe the oil pressure indicator.

14} Note down the temperature of the water on the temperature gauge. 

15} Note down the oil pressure at full throttle.

 16}Compare the observations made with the manufacturer’s specification.

17} Depress the accelerator steadily to full throttle, and observe the exhaust smoke. 

18} Note down the colour of the smoke as black/white/ blue. 

19} Run it at idle speed for a few minutes to bring it to operating temperature.

20} Loosen the injector one or two turns and crank the engine to blow off the carbon and dust around the injectors.

 21} Remove all the injectors.

Dry test 

22} Install the compression gauge `1' on the first cylinder. 

23} Press the accelerator lever. 

24} Crank the engine with the starter motor and read the highest pressure on the compression gauge.

 25} Note the reading and release the pressure from the compression gauge. 

 26} Repeat the procedure for all the remaining cylinders and note down the reading.

Wet test

 27} Put 10 ml of engine oil in the first cylinder

. 28} Crank the engine to circulate the oil around the piston and piston rings

. 29} Repeat the procedure to take the compression pressure reading as given in the above steps.

 30} Take the reading for all cylinders by pouring oil in each cylinder.

 31}Note down the difference of the readings in the dry and wet tests.

32} Put back all the injectors and tighten at the recommended torque.

33}Fit the fuel pipe lines and bleed it. 

34} Start the engine and check for leakage at the injectors.

 35} Check vibration of engine in idle speed.

36} Overhaul the injectors to improve the performance of the engine. If needed.

37} Refit the injectors and connect the fuel lines and start the engine. 38 Adjust and set idle speed of the engine.

Requirements

 Tools/Instruments 

 Trainee’s tool kit - 1 No.

 • Compression gauge - 1 No.

 Equipments/Machineries

• Multi cylinder diesel engine - 1 No.

 Materials/Components

 • Tray - 1 No. 

• Cotton cloth - as reqd.

• Kerosene - as reqd. 

• Soap oil - as reqd.

 • Lube oil - as reqd.

 • Diesel - as reqd.