Serviceable engine should work smoothly and rhythmically, without extraneous sounds, the extra shaking and vibration. Share secrets check working motor.
Start the engine
The test engine should start with its launch. It is desirable that the engine was cold, unheated. On how to start a cold engine, you can determine its condition and to detect hidden defects.
Sometimes the sellers knew about the problems of the engine, periodically heated to facilitate starting. In this case you should wait for the motor to cool and ask to have it cold.
Before you run please note on the dashboard. After switching on the ignition, the indicators of the oil pressure gauge and lack of battery charging (usually red) should be illuminated. If not, ask the owner of the car, serviceable bulbs in the indicators, or it may be faulty sensors?
The engine is in working condition should start almost immediately, while the starter when you run a healthy engine should not exceed 2-3 seconds. After the engine is started all the red lights on the instrument panel goes out.
Allow the engine to run for 15-20 seconds, and then stop it.Turn off and again turn on the ignition, if the indicator oil pressure switch, therefore the oil pressure in the lubrication system fell below 0.3 kg/cm2. The serviceable engine oil working pressure in the system must be kept for at least 5 seconds. If it is not, therefore the engine order is worn and there is a rapid leakage of engine oil into the crankcase through the gaps of the bearings of the crankshaft.
Check the wear of piston group
After the engine warms up to operating temperature and will operate in the mode of idling, gently open the oil fill cap and carefully look inside the engine. The presence of oil mist inside and single drops of oil jumping out through the mouth is normal.
Ask the owner of the machine slightly press on the accelerator pedal. If from the oil filler neck come out the exhaust gases, so the combustion chamber they break in Karter the engine, creating excessive pressure. Hence, the compression rings of the pistons, and possibly the entire piston group — are worn,
The excess pressure in the crankcase, you can define another way. At idle the engine remove oil fill cap, turn it upside down and put on the neck. Bouncing cap will witness the excess pressure in the crankcase. Conclusion – the motor is worn out order.
what will tell you the exhaust fumes
Note the color of exhaust gases. In a car with a warmed up engine in warm weather, the exhaust gases should be almost invisible.
White smoke will indicate leakage to the combustion chamber of the engine coolant through the damage in the gasket between head and cylinder block.
In bluish-gray color of the exhaust gases stains the engine oil entering the combustion chamber due to worn valve seals or oil rings of the pistons.
Black color smoke from the exhaust pipe may be due to poor fuel quality, lousy adjustment of the carburettor or injectors, improper operation of the vehicle.
Tightly cover with the engine running the exhaust pipe with the palm of the hand. If the engine stalled after a few seconds — look in the muffler, resonator, catalyst, or in places of their joints cracks and holes through which the exhaust gases are vented to the outside.
By smooth pressing a pedal of an accelerator the engine speed should gradually increase when you release the gas pedal, they should also gradually decrease. By sharp pressing on the accelerator there should be no gaps or pauses in the set engine rpm. If this is true and the engine on all modes works without vibrations, knocks or noise, with high probability it can be argued that he is serviceable.
Good luck to you! No nail, no wand!