The ignition candle is an important constructive component in the car ignition system. It is responsible for the direct ignition of the air-fuel mixture in the gasoline engine. The ignition of the mixture occurs during the passage of the spark between the candle electrodes, so its other name is the spark candle. About this further in the article.

Spark plugs, device and action principle

The main components of the ignition candle elements:

• The sealing ring - prevents hot gases from entering, which are in the combustion chamber.
• Electrodes (central and lateral) - skip the spark that ensures the ignition of the mixture.
• Insulator ribs do not allow electricity to affect the surface of the insulator.

  

• The insulation sector is responsible for the quality of the device, helps to avoid overheating.
• Contact Output - Connecting an item to an individual ignition coil either to high-voltage ignition system contacts.

The principle of operation of the spark plug is as follows: The high voltage current is supplied from the ignition coil through the high-voltage wire distributor to the candle. A spark discharge is created between the side and central electrodes of the candle, the fuel mixture is flammified from it, which is in the combustion chamber of the power unit at the end of the compression tact.

How to find the place of installation of spark plugs in your car

Immediately after opening the hood of your car or removing the casing, you will see the harness of 4-8 wires that lead to different parts of the engine. Spark plugs are in DVS and attached to the ends of these wires under the candle caps. On 4-cylinder power units, the ignition candles are located in a row on the side or upper side of the motor. In the row 6-cylinder, they are located on the side or upper side of the motor head. On V6- and V8-cylinder power units, the candles are divided into both sides of the motor. It is worth noting that plastic protective caps are mounted on the engines of some cars that need to be dismantled to access the candle wires - you are traced on them and track the location of the candles.

Why should I study the car operating manual

First of all, it is necessary to read the instructions for using the vehicle, where you find the location of the candles, their number, as well as the size and "depth" of the key to unscrewing them.

Why you need to numbered the ends of the wires

Be sure to check the ends of the wires corresponding to each cylinder, so as not to forget their correct sequence of connection after replacing the candles. At the same time, it is desirable to inspect the wires and try to detect any cracks and damage, upon the presence of which the wires must be replaced.

Safety and protective equipment

Before replacing the candles, you need to make a motor cool. If the power unit has already worked for a certain time, the exhaust system manifold and candles can be hot. You need to unscrew the candles only when the power unit is cooled enough. All operations should be performed in gloves.

Tools, fixtures and consumables

While the engine is cooled, prepare the required tools:

1. Extension.
2. Candle head.
3. Ratchet key with ratchet mechanism.
4. A set of probe to measure a spark gap or a ignition candle gap meter with graduation.

How to remove an old spark plug, tips and recommendations

Remove the first spark plug. To do this, it is necessary to grab the cap of the wire as close as possible to the power unit and pull on itself, carefully removes its terminal from the head. It is impossible to pull for the wire, otherwise there is a big risk of tearing the wire of the cord candles. Using an end spanner with a ratchet and extension gently and slowly remove the spark plug from the landing place.

When checking the candles onto the suitability, you must remove one of the socket and check the candle clearance. If you see a frightened electrode, then you turn this into place before unscrewing the rest of the candles, tighten with the required effort and go to the automotive spare parts store for new candles. You have to unscrew all the candles at once, while remembering the procedure for connecting the wires. It should be known that the candles ignite the fuel mixture in a particular order, so the incorrect connection of the wires can lead to interruptions or a complete failure of the power unit and damage.

If you have twisted a few candles at the same time, you need to mark the sequence of connecting the wires and the corresponding candles them by gluing small pieces of insulating tape. Start the desired number of slices. Isol first on the wire, after which the same number on the corresponding candle.

What is a candle gap, how to determine the size of the candle clearance

The spark gap of the candle is the distance between the lower and the upper electrodes, which is necessary for optimal work, as well as the ignition of the fuel mixture. It is measured by a special tool. Nowadays, most candles are sold in adjusted according to a certain marking of the form, but it is desirable to double-check. Look at the user's manual and find out the normal candle distance. Take advantage of the ignition candle gap meter with a graduation or a set of probes to check it.

What a gap is considered the norm

This distance should be in the range of 0.71-1.52 millimeters with a small error, depending on the model of your car and a set of certain probe.

What tool is measured by the gap

Before replacing the candles, you need to buy a gap measurement tool - a set of special probe. To check the gap, as a rule, a gap gap meter is used with a graduation with which you can adjust the distance required for the appearance of the spark. Check using a set of probe gives a more accurate result. In addition, the set of probe has a wider range of use.

How to adjust the gap

If the gap of the candle is more necessary, however, the candle performs its work well and can be adjusted, you can try to change the size of the gap, cautiously pressed to the wooden surface of the side electrode with a candle inserted into the clearance of the required thickness, begging it to the desired distance, or you can simply Buy new candles. Most often, the candles are recommended to change after every 20,000 mileage kilometers or in accordance with the period specified in the instruction manual for your car. Spark plugs are not very expensive, so it is advisable to regularly change them in order to obtain a good spark and uninterrupted vehicle work.

How to determine that the spark plug must be replaced by which signs

Small contamination of the candle, which works in this range of characteristics, is considered the norm. The replacement is subject to spark plugs with white nagar around the electrode, or when the part of the electrode is missing or melted. The presence of broken, smoky or bent candles can talk about the mechanical problems of the motor and requires urgent consultation of a qualified mechanic or checking the vehicle in the repair shop.

How to choose new candles, selection criteria

Pick up the candles suitable for a certain brand of machine and year of release will help the instruction manual for the car or a brochure from the automobile spare parts store. There are hundreds of different types of candles from platinum, Iridia, Yttria and so on with various spark gaps, the cost of which ranges in the range of $ 2-15 per piece. As a rule, candles, the coating of which is made of precious metals, are more expensive and much better opposed wear. If there are doubts, consult with your auto parts manager or refer to the acquisition of original spark plugs to an authorized dealer.

It is advisable to find the same candles as installed on your car at present. Do not buy cheap candles or try to repair what works well. The manufacturer did not just install such candles so much, so it is not necessary to complicate your life and, if possible, simply choose exactly the same, but provided that the ignition candles are mounted correspond to the vehicle specifications.

Spark plugs with a fixed gap and spark plugs with adjustable gap, what is the difference, which is better

You can buy candles with both adjustable gap and fixed. If you select Candles with a adjustable gap, then with the next diagnostics you can make the required adjustments. Most importantly - make sure that the value of the established gap meets the requirements of your car power unit. In this you will be assured only if the personal check, so remove from the packaging, and plug directly measure the size of the clearance.

How to check wiring wear and clean the terminals

When replacing candles, you will have a great opportunity to clean the terminals and checking wiring. Use compressed air or wire brush to clean the seat of the candle and wire connector.

When you need to replace the wires

Wires are replaced if they have any damage and cracks. Detect defects by their visual inspection.

Installing new candles with your own hands, tips and recommendations (step by step)

• With the help of the candle head, turn out all the candles from the motor and change them to new ones.
• Slightly tighten with a ratchet (about 1/8 turns), but only an effort of one hand.
• Do not delay the candles too much, because it can be easily damaged by the thread on the power unit, which will lead to time consuming and expensive repair.
  
• Wires must be connected to those ignition candles to which they were originally connected.
• Remove tags from the tape.

Why and why professionals advise lubricate candles before installing

Before installing the candle, it is necessary to lubricate. When mounting into an aluminum motor block, try putting a little lubricant for fasteners on the carving of the candle. Lubrication for fastening compounds prevents chemical reactions between metals of various types. You can also use a small amount of silicone dielectric compound - apply it to the wire connectivity terminal to the candle to ensure easy disconnection in the future. If the new spark plug does not go on a thread, unscrew it back and place at a correct angle relative to the landing place, which will save the candle and the head of your power unit from damage.

Tips Prof.

1. When removing, it is necessary to pull and turn only the tip, however, not a high-voltage wire. If the wire breaks away from the tip, you will have to buy new high-voltage wires. There are special tools intended for this event.
2. To definitely not confuse the wires when connected, change the candles one, so that the other wires remain in their places.
3. Diesel power aggregates have no ignition candles.
   
4. Candle heads differ from the usual end heads in that inside them there is a special seal that locks the candle in the head. If you still decide to use the usual head, there is a risk to drop a candle. In this case, the electrode will actually be brightening, which will lead to a change in the gap, and you will have to clean the candle from dirt and exhibit the gap again.
5. If you want to be sure that the candles are not tightened too much and do not hang out, twist them using a torque wrench.