Vigor Equipment V4461, Руководство по эксплуатации

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3 Design and Function
3.2 Application: Compression test in petrol engines
Follow the instructions provided by the vehicle
manufacturer during any work you do!
3.2.1 Before starting the operation
• The engine of the vehicle must be in an operating temperature state for all works.
Risk of burns when the engine is at operating state temperature, do not touch any hot parts.
• Allow engine to warm up. Apply the vehicle handbrake.
• The engine is switched off!
• Disassemble all of the cabling of the ignition system, ignition coils and the injection nozzles.
Hinweis: Only the removal of the high voltage ignition cable can cause damage to the
ignition system!
Caution: With live parts there is a danger of electric shock!
• Remove the spark plugs, observe the installation / removal sequence.
• If necessary, clean the thread of the spark plug.
3.2.2 Application: Compression test in petrol engines
• Remove a suitable adapter if necessary and screw the manometer with hose finger-tight
into the spark plug thread.
• Start the engine and at the same time give it full power until the pointer of the manometer
no longer rises and no further compression is built up.
• Make a note of the displayed values and perform the test on the remaining cylinders.
• To do this, proceed as previously described.
3.2.3 Test results
• Observe the vehicle manufacturer‘s instructions.
• With intact cylinders, the maximum compression should be reached immediately
after starting.
• The piston must be checked for damage if there is no compression on the cylinder
and the spark plug is oily. A combustion temperature that is too high and uncontrolled
combustion can damage the piston.
• If the compression is lower for two opposing cylinders than for the rest of the cylinders, the
cause may be the result of a defective cylinder head gasket in the transition area. For this
reason, the spark plug must also be checked for oil and water residue. This also indicates a
defective cylinder head gasket.
• If the compression of a cylinder is lower than that specified by the manufacturer, add a little
oil into the combustion chamber and check the compression again. If a significantly higher
compression is achieved, the cause may be worn piston rings. If the compression remains
unchanged, a valve may be damaged or there may be a defect in the camshaft.
• If the measured compression for all cylinders is below the manufacturer‘s specifications, this
may be a result of age-related wear of the engine. The engine can be disassembled and
surveyed for the exact diagnosis.
• After completing the compression test, assemble the spark plugs and disassembled ignition
components again in the prescribed sequence. Follow the instructions provided by the
vehicle manufacturer!