The main signs of a malfunction of spark plugs: the list, the reasons, features of repair

Spark plugs are an integral part of the engine of any gasoline car. It is this part that provides the necessary spark, which then ignites the mixture of air and fuel in the combustion chamber. Like all other engine parts, they can fail, and if there are even the slightest signs of malfunction of the spark plugs, they must be eliminated.

If the part fails, the load on the ignition coil also rises , which can also break down as a result. The cost of a candle is incomparable with the price of a reel. If you continue to drive on faulty candles, the driver will observe the unstable operation of the power unit at idle. Often, when everything is in good order, the motor's work at 1000 rpm. Smooth and soft. If the spark plugs fail, the tachometer needle will jump, and the motor will vibrate and produce unpleasant hard sounds. Today to detect signs of malfunction of spark plugs to the motorist will help the computer. A few decades ago this was not yet, and those who independently serviced their cars had to conduct diagnostics of these elements. In order to make the correct diagnosis, you need to know the typical problems with candles and be able to detect them visually.

What are the symptoms of the malfunction of the spark plugs?

So, when the plugs are out of order, the motor is broken. The engine refuses to perform the functions assigned to it. Let's give a list of signs that require urgent intervention of a specialist. If the engine starts with serious and visible difficulties, it is a signal for the owner to diagnose and replace the spark plug. Also about the failed candle will tell the nature of the motor: if the unit is trod, twitching, and thrust and power is not, then this is another sign. Along with this, often with malfunctions of the spark plugs , the fuel consumption increases several times , and the CO predominates in the exhaust gases. If there is low power or the motor does not want to gain momentum when the accelerator pedal is pressed, then this also indicates the need for diagnostics.

If you pay attention in time to these basic signs of malfunction of spark plugs, then the situation can be solved. If you do not pay attention to these signals, then the result will be deplorable.

Consequences of faulty candles

In the cylinders, detonation arises, resulting in a powerful shock wave. It can provoke a detonation of the charge that has remained in the cylinder. After that, the motor will completely lose its power. In the process of this impact, due to severe overheating, the crankshaft, pistons and connecting rods suffer. Also burn small parts and destroy the oil film on the cylinder.

When it is necessary to change candles

Each auto-adviser recommends a scheduled replacement during maintenance. But experienced drivers disagree with these statements. Most motorists perform replacement of candles by mileage - every 20-30 thousand km. Producers of candles recommend changing the classic candles for 15 thousand km. Details from platinum can be changed less often - their term leaves on 100 thousand in km. Do not wait until the first signs of malfunction of the spark plugs appear. If low-quality fuel is regularly poured into the tank, the candles will start to accumulate the carbon deposits, and the failure will be earlier than the producers established by the terms.

Diagnosis: we are looking for a candle with a defect

Problems can be defined visually even with the naked eye. However, the breakdown is obvious when the car runs unevenly and stalls. It is worth remembering that faults of this kind make it impossible to ignite the fuel-air candle in the cylinder.

As a result of the fact that the fuel does not burn, it can get into the catalyst. In this case, there will be a strong smell of gasoline. Another clear sign of a malfunction of the candle is a significant increase in fuel consumption. This happens because the mixture burns incompletely due to misfiring.

For effective combustion in gasoline engines, it is necessary that the temperature in the cylinders reach 400-500 degrees or more. This is possible by compressing the fuel mixture, which further increases the temperature. Only so the mixture is easy, and most importantly - completely, will ignite and burn.

However, high temperatures do not have the best effect on the resource of candles. Most often on old details are found layers. Also on the electrodes, one can see deposits that affect the quality of the spark. It should be remembered that the spark plug has a homogeneous color and a uniform shape, and there are no deposits.

Testing of spark plugs

The normal part has practically no burn-up at the electrode. With such a candle, the motor will work like a clock. It is important to know what may be the malfunctions of the spark plugs. This will help novice motorists.

Diesel soot

If the plaque is seen on the grounding element, as well as the electrode and the candle body, then such a candle is malfunctioning. The reason for this is improper preparation of the mixture. For example, the composition may be too much air or, conversely, a little. Also, these deposits can appear as a result of contaminated air filters, malfunctions in the operation of the injection system, failure of temperature sensors or a lambda probe.

Butter on candles

In this case, the grounding element, housing and electrode are covered with a uniform oil coating. These signs of a malfunction of spark plugs are shown because of excess quantity of oil in engine cylinders. This phenomenon occurs due to overflow of oil in the motor. In addition, this feature can talk about worn piston rings, pistons themselves or valve guides. On cars with a turbo-compressor, candles in oil can talk about problems in the operation of the compressor.

Lacquer deposits

If deposits of a brownish-yellow or green hue are observed on the candle, the most popular reason is the presence of additives in gasoline or in oil. These are symptoms of the engine running on a too lean fuel mixture or gas.

Slag deposits

They can be observed on the grounding element, as well as not electrodes. These are large deposits of fuel and oil. The reason for this may be the presence of additives in the oil, which are becoming more popular with lubricant manufacturers. This can also be the cause of the malfunctioning of both the motor itself and the ignition system. Often you can observe such signs of malfunction of spark plugs VAZ-2110.

The central electrode is molten

You can see the molten central electrode and the melted edge on the grounding element. The reason for this may be overheating of the spark plug as a result of incorrect operation of the ignition system. These are signs of malfunction of spark plugs VAZ-2114. On such cars it is often possible to observe problems with the ignition module.

Electrode of a candle very quickly worn out

On electrodes and grounding elements it is possible to observe the raised deterioration as a result of which the material of critical elements of a candle was damaged. The reason for this is low-quality gasoline with a lot of additives. Also, oil with additives can lead to this. Quick wear of the candle can be observed with detonations or overheating.

Candle melted

This is indicated by strong deposits on the grounding element and on the electrode. This happens due to the presence in the chamber of combustion products of various deposits that can self-ignite. It may also be a sign of an improper valve operation. Well, the most popular reason is bad fuel.

Worn connector

Often, the wear of the candle occurs in the place where a spark is created. However, damage can also occur on the other side, where the high-voltage wire is connected. The cause of this malfunction is the old connector on the wire or overheating.

Check of spark plugs

In turn, the candles are unscrewed with a special key and listen to the work of the motor. If the engine has not broken the rhythm and continues to work stably with normal sound, then at the moment the idle candle is pulled out. It is also possible to disconnect the wire from the spark plug and touch it to the cylinder block. If there is no spark, then the candle needs to be changed. Also, the electronic control unit can inform about malfunctions. Take, for example, the French car "Peugeot Partner Tipi". Spark plugs, the signs of malfunction which can be recognized not only during a visual inspection, the owner can check with the help of the computer. Apparently, this is not so difficult. In fact, knowing this is very important. Defective spark plugs - improper operation of the motor, damage to critical components and expensive motor repairs. And if you know how the spark plugs work, and their signs of malfunction, big problems with the motor can be avoided.