You will need
  • gloves
  • - clean cloth
  • - a white sheet of paper
The external examination. Lift the hood of the car and inspect the engine compartment. Here you should pay attention to oil spots and stains: on a healthy engine shouldn't be. Even slight traces of oil may in the future mean for you, the problems related to his leak. Pay special attention to the areas around the distributor and fuel pump. Ifthe reason for the drip tip can become as leaky gaskets and rubber seals and is loose clamps on the hoses. Another reason for the traces of oil can be a loose fitting cap cylinder head: inspect the junction, make sure it has no traces of oil, no sealant. Even if the current owner before the sale brought the engine in order, he could have something to miss. For example, traces of faulty motor could stay on the inside of the hood, so carefully inspect it.Inspect bolts and nuts: if you are around or you will find scratches, albeit small, it can serve as a clear sign that the motor is at least opened. And well, if in this case the seller to inform you, that the engine recently had a routine overhaul.
Inspect condition of oil and antifreeze. Check the oil using the dipstick, the antifreeze - just unscrewing the cap of the appropriate tank or radiator. The oil should be transparent, have a normal, not too viscous and the smell. The oil must be free of impurities or air bubbles, and on the dipstick there should be no divorces or outside of the RAID. The same applies to antifreeze: liquid should be clear, have a characteristic sweet smell and no oil stains or bubbles on the surface.The bubbles in the liquid - the first sign of leaks, remember: this is a very serious problem. In the case of, for example, antifreeze, air bubbles can indicate a coolant leak in the engine because of a leaky gasket or crack in the cylinder head, which is completely unacceptable. The antifreeze corrodes the piston rings and causes the condition of the motor permanent damage.
Unscrew the oil fill cap neck. Inspect the cover: in any case, under it or on the edge of the mouth should not be foam or plaque. Dense plaque characteristic white-yellow color means that the engine gets the coolant. About the consequences of such a failure we have already discussed in the previous step.
Inspect rubber products and candles. The seals and hoses must not be external signs of damage and cracks.
If in the engine compartment dusty and dirty, please wear gloves and arm with a cloth to inspect all nodes: years of grime can hide many defects.
If possible, remove one or two candles, their appearance can be very telling.
Under normal circumstances, the spark will cover a very thin layer of light gray or light yellow coating, and the electrode may be slightly frayed. Candles with a crack on the insulator surface means that the engine will operate with a thud, and the candle with light rich sediments talking about incorrectly chosen oil. Melted Central electrode of a candle can signal a whole bunch of issues: from early ignition and poor fuel until the fault of the valves or ignition distributor. The formation of a kind of glaze consisting of carbon black, or strong wear of the electrodes means that used fuel or oil with lots of additives. Oily plugs can be a sign of too much oil in the lubricating system, and the more serious wear of rings, cylinders and valve guides. Finally, the soot on the plugs indicates that the mixture or the air filter, which have not changed.
Start the engine and pagesuite on the spot. The cranking motor should not make extraneous sounds and screeching. Not to say that the engine should start on the first attempt, regardless of the degree of heating and the weather conditions. To work the motor should smoothly, without interruption. If the engine jerks, there are extraneous vibration, and the rhythm can be called inconsistent, it is likely that the motor troit. This means that not working some of the cylinders. Whilethe reason may be a fault with the ignition system, incorrect operation of one of the candles, burned piston or rich mixture. In any case, the problem should be discussed with the owner.
Read the readings. When the engine is running after warming up the arrows of the pressure sensors and oil temperature must be within normal limits, is in the middle position.
Look at the smoke from the exhaust pipe. If when starting the engine white smoke appeared abundant, but then after a short period of time is completely gone, it is likely that it was just condensation and not to worry. If the smoke continues to pour out of the exhaust pipe, by its color and smell, you can conduct a rapid diagnosis. So, white smoke, or smoke with a slight bluish tinge, which dissipates quickly and leaves in the air a sweet smell - a clear sign of the presence of antifreeze in the cylinders of the engine. Blue or grey smoke (maybe with a hint of white), which for a time hangs in the air light purple or grey smoke means that the combustion chamber gets the oil. The elimination of both faults can cost you dearly, so it is better not to take chances. Finally, the black smoke means that the fuel and air is burned inefficiently. Ifthe reason can be many faults: SamAccountName air nozzles, leaking injectors, faulty lambda probe or MAF sensor. The consequences are that the engine wear is considerably accelerated, and the exhaust becomes highly toxic.
Go for a test drive. It needs to identify those flaws that you might not notice when the engine is idling. Check how the motor responds to the drive of the high and low the motor as it accelerates and behaves in dynamics under load. Alert you need background noise, knock, rough running and loss of power and, of course, the smoke from the exhaust system.