The engine of a car is its heart, the foundation of smooth operation and long service life. Therefore, it is so important to check it at the first inspection of the car, this, in general, simple procedure will protect you from major problems and headaches in the future.
The right decision when buying a used car is to have it checked by specialists at a service station. You need to drive the car there immediately. If this is not possible, then you need to rely only on yourself. With the check of the interior and the integrity of the body, problems may not arise. But when making a purchase, checking the condition of the engine is not a trivial task. How can this be done?
It is necessary to check:
- gloves;
- a clean cloth;
- piece of paper.
First, look under the hood. You will not see oil stains and drips on a motor that is in good working order. Even the smallest sign of oil leakage will result in major problems later. The area around the fuel pump and ignition distributor needs special attention.
Decaying oil seals and rubber seals can easily provoke oil leakage, as well as clamps that are poorly tightened on the pipes. If there is a gap between the cover and the cylinder head, then this will most likely be one of the causes of the leak. Make sure that there are no oil traces or stains of the hermetic paste at the joint where the cap contacts the head.
When an owner sells a car, he usually brings the engine into more or less good condition, but he may miss some trifle. If the motor was previously disassembled, then small scratches will be visible on the bolts and nuts. Pay attention to this clear sign. Some sellers prefer to hide even about a routine inspection of the insides of the motor. Therefore, try to inspect everything very carefully (even on the inside of the hood, engine malfunctions could leave characteristic marks).
Check oil and coolant. Antifreeze is easy to check - unscrew the cap on the radiator or tank, and the oil by dipping a dipstick into it. Just look at the consistency of the oil - it's good if it is not viscous or with some impurities. It must also be transparent and free of air bubbles. There should be no plaque or streaks on the probe.
Antifreeze should be of the same quality as the oil: without bubbles and oil stains on the surface. In general, a good antifreeze is a clear liquid with a specific sugary odor. When it leaks from the tank, small bubbles form on the surface. Antifreeze leakage is a harbinger of a serious problem in the future. If a crack has formed in the head of the block or a gasket has leaked, then the cooling liquid will flow into the motor. This can cause serious damage to its condition by corroding the piston rings.
The engine has a hole through which oil is poured (oil filler neck). Take a look under its cover. If there is foam or plaque under it or on the walls of the neck, then this is a very bad symptom. If the antifreeze leaks into the engine, then you will definitely see a yellowish bloom and a dense consistency. We have already talked about the consequences of this for the engine.
Check candles and rubber products. Hoses and gaskets must be undamaged and free of cracks. Many defects may not be visible under a layer of dust and soot. Wear gloves and thoroughly wipe down all accessible inspection parts, even if the engine compartment has not been washed for several years.
Unscrew a few candles if possible. By their appearance, you can carry out a small diagnosis.
If the candles are normal, then they will be slightly oxidized (covered with a grayish or light yellow coating) and with a slightly worn electrode. The engine will knock during operation if the ceramic spark plug insulator is cracked. Low-quality engine oil leaves a lot of light-colored deposits on candles. Early ignition and poor fuel can melt the center electrode of the plug, but this is a recoverable problem. It will be worse if this is a symptom of a problem with the ignition distributor or valves. Fuel and engine oil manufacturers can use many additives. In this case, the electrode wears out a lot, and the candle becomes covered with an abundant layer of soot.
Worn piston rings, valve guides, and even abrasion of the cylinders can all lead to oiling the spark plug. Pay close attention to this. However, oiling can also occur for a more banal reason: oil is poured into the lubrication system in excess.
An old air filter or a problem with the air-fuel mixture will leave a layer of burning on the candles.
Start the car and click on the gas. The starter should not make any extraneous sounds or rattling. The air temperature or the degree of heating must not affect the engine. It should start on the first try.
If one of the cylinders is out of order, then the motor will triple. At the same time, the rhythm of its work becomes inconsistent, and the engine itself shudders from vibrations and twitches. There are several reasons for this: a piston that could burn out, a failed ignition, problems with spark plugs, and an overly saturated mixture. The motor must run smoothly. Talk to the owner if there are any problems.
Warm up the engine and take a close look at the instruments that measure oil temperature and pressure. Ideally, the sensor arrows should indicate the middle position. Instrument readings must be normal.
Take a closer look at the exhaust. If, when starting from the chimney, thick white smoke poured out, and immediately stopped, then you do not need to worry. It was just condensation.
In general, it is realistic to carry out diagnostics on your own, studying the exhaust.
When burning in the cylinders of the coolant, a white bluish smoke with a sweetish odor appears, which instantly dissolves.
A whitish blue smoke hanging in the air, a lilac haze hovering above the surface of the earth is a sign of burning more than necessary amount of oil.
If the fuel combustion has a low efficiency, then a black exhaust will appear from the muffler. Unfortunately, there are many reasons for this: clogged air nozzles, a failed air flow meter, depressurized nozzles, as well as a broken lambda probe. Highly toxic exhaust and accelerated engine wear are the consequences of malfunctions. Repairing these faults can cost a pretty penny. Therefore, try to identify them in advance.
Take a test drive. If the engine does not tell everything about itself, running idle, then the race will show everything. Do not be lazy to test the dynamics of the motor during acceleration and, of course, with loads. Feel how low and high revs affect the ride of the car. Pay close attention to suspicious noises, which exhaust system is emitting smoke, sudden loss of power, extraneous knocking, and whether the engine runs smoothly under such different conditions.
