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The condition of the candles will tell a lot about the car – even if one of them fails, the car will not like it, expect problems and malfunctions in the engine. Therefore, when conducting a technical inspection, independent or in a car service, do not forget to evaluate their condition. Nagar or plaque on candles will tell you about a particular problem.
Together with an auto expert, we will tell you where the candles are located, what they are for, how to change them correctly and how much they cost.
What are spark plugs for?
– A candle in a car is a device for igniting the fuel-air mixture in heat engines. In simple terms, this is what gives a spark to the engine, explains car mechanic and auto parts store owner Nikolai Voronin. The car cannot run without spark plugs.
The engine starts when the air-fuel mixture ignites due to a spark formed between the spark plug electrodes. There will be no spark without candles, which means that candles can be safely called the heart of the engine, a lot depends on them.
Where are the spark plugs
Engine 8-valve
In these engines, the spark plugs are screwed into the side and go into the cylinders. All four candles have armored wires – just the same they give a spark to the candle, and the engine starts.
Engine 16-valve
Compared to the 8-valve engine in the 16-valve engine, the spark plugs are screwed into the cylinders and they are not on the side, but at a right angle. There is also another difference – in this engine, four separate ignition modules go to the spark plugs, and on the 8-valve one – one large one.
How to test spark plugs for performance
When the car starts to “troit” or work unevenly, motorists, before contacting a car service, look under the hood to assess the condition of the candles. There are several ways to test spark plugs for performance.
We remove the wires from the spark plugs in turn with the engine running.
This must be done very carefully, the car must be running. We remove one wire from the candles and carefully listen to the sound of the motor. If after you removed the wire, the motor does not change its sound of work, then this candle is faulty. Most likely, a failed candle will have to be replaced, and sometimes it is enough just to clean it.
Checking spark plugs with a gun
Auto shops sell a special “gun” for self-checking spark plugs. We insert the candle into a special hole and see if there is a spark. If not, then the spark plug needs to be replaced.
Checking spark plugs with a piezo lighter
If you do not want to spend money on a gun, you can check it with a piezo lighter. This is also easy to do – you need to take the wire that comes from the piezoelectric module, lengthen it and attach it to the tip of the candle that you just removed from the car. Further, everything is knurled: there is a spark – wonderful, absent – a candle for replacement.
– It is important and necessary to check the candles for performance, since faulty candles are fraught with a lot. For example, a car may increase fuel consumption, reduce power, the car will go slower, it will be hard to drive. The engine may also be unstable – it “troit”, hard to start – all due to the fact that with worn candles the distance between the electrodes increases. First, a motorist can be overtaken by misfires, and then completely – the absence of a spark, the car simply will not start, – the expert comments.
Also, faulty spark plugs can bring more serious and “expensive” problems to your car. For example, the catalytic converter may fail. The air-fuel mixture that has not burned out is burned out in the exhaust: the temperature in the converter rises because of this, burnout occurs in the honeycombs, and this expensive part fails. Also piston rings can say goodbye to the car. A faulty spark plug has a very high temperature, leading to pre-ignition. The air-fuel mixture explodes before the piston reaches the required point in the cylinder, and the protective “oil wedge” on the cylinder walls is destroyed.
How long does it take to change the spark plugs
The expert advises not to blindly believe the regulations – everything is individual in this matter. In general, ideally, replace old candles with new ones every 30 km. But, if the candles are still working properly, without bringing problems to your car, what’s the point? Just a waste of money. Some candles can last 000, and 60 km, and even more. Just check the spark plugs every 000 km and, of course, if you notice that the car has started to run unevenly.
“On “charged” engines (sports, racing cars), if you don’t change the spark plugs for a long time, you can say goodbye to the engine, because the spark plug insulator tends to break off and fly into the cylinder, says Nikolai Voronin.
How to replace spark plugs
— In fact, the spark plugs are very easy to replace. But still, it’s better to stick to the algorithm, especially if you are changing candles for the first time, the expert continues:
- It is necessary to remove the protective cover from the engine and other elements that interfere with access to the candles.
- The second step is to remove the dirt around the candle. This can be done with a compressor or brush. It is impossible for this dirt to get into the candle well.
- With your hand, you need to grab the cap of the wire as close as possible to the motor, and then gently pull it towards you to remove the terminal from the candle. Do not pull sharply so as not to damage the wires or the cap.
- Prepare a socket wrench with an extension and a candle head in advance. With it, you will need to unscrew the candle. Immediately put a new one in its place, do the same with the rest of the candles and connect the wires so as not to get confused. Be careful not to twist the candles!
- Connect the plug to the spark plug.
- Replace all previously removed protective elements and protective cover.
Popular questions and answers
Popular questions about replacing candles and the price will be answered by Nikolai Voronin, car mechanic and owner of the AutoLiga 116 auto parts store in Rostov-on-Don.