Spark plug diagnostics
If you suddenly feel that your car is having problems starting the engine or the engine is no longer running smoothly even at idle, then the spark plugs may be to blame.
Taking into account the fact that they need to be changed every 35-45 thousand km, you need to know how to check the spark plugs and remember that defective spark plugs may stop working much earlier than this.
If interruptions in the operation of the car begin to occur, then first check their operation.
Inspect your spark plugs regularly
Causes and first signs of dirty spark plugs
In an idealized world that does not yet exist, spark plugs are replaced every 35-45 thousand kilometers. But we live in the real world, in which we have to solve problems that arise out of nowhere every day.
If, as usual, winter comes unexpectedly and you have to change the tires to summer ones, the engine will go haywire.
In this case, when the car starts to start intermittently or starts idling rough, the owner will definitely need to get under the hood and diagnose the operation of the spark plugs.
Video: spark plugs, checking
Those who brush off problems should think about whether they should ignore interruptions in the ignition system and wait until the problem goes away on its own? After all, a machine is not a person; no cases of magical healing are known yet!
Therefore, if interruptions in the operation of the engine begin to occur, it begins to “triple”, you need to get ready for work and, using a special testing device, begin to inspect the spark plugs. Additionally, you can do another useful thing - check the compression in the engine.
Diagnostics of spark plugs - removing the root cause
Typically, spark plugs for cars that are used in difficult conditions (for example, on the roads of Ukraine or Russia) are designed for a mileage of up to 35 thousand kilometers. This means that with constant use of the car, you need to replace the spark plugs at least twice a year - before the spring and autumn periods begin.
1 - normal spark plug, 2 - high fuel consumption, 3 - weak air-fuel mixture, 4 - excessive amount of additives, 5 - poor condition of oil seals, 6 - destruction of one of the valves or breakage of the partitions between the piston rings, 7 - long-term engine operation with detonation or the use of fuel with a low octane number, or very early ignition, 8 - oil combustion due to wear or sticking of the oil scraper piston rings
There is no need to be afraid if you do not know how to check the performance of spark plugs and think that this is a complex process. Even a blonde, who is so fond of being ridiculed in jokes, can do this, so not knowing how to check spark plugs should not be an excuse or be perceived as a joke.
How to check if a spark plug is working properly
Before starting the test, make sure the ignition system is turned off.
After this, inspect the marks on the high-voltage wires; the cylinder numbers should be indicated on them; if there are no such marks, then each high-voltage wire must be marked with tape or a marker.
Then carefully remove the tips from the spark plugs, to which the high-voltage wires are connected; pulling the wire while performing this operation is strictly prohibited.
When unscrewing the spark plugs, it is necessary to blow through the area around them with compressed air, this will prevent dust and dirt from entering the cylinders.
You can now unscrew and remove the spark plugs using a spark plug wrench or a suitable socket wrench.
If you need to unscrew the spark plugs in a six-cylinder V-engine, you must use a deep socket wrench that rotates on a flexible drive or on a universal joint.
After these operations are completed, you can proceed directly to checking the spark plugs. It must be remembered that there must be a gap between the electrodes strictly equal to 0.7 mm. You can measure it using a probe. If necessary, you need to adjust the gap with a special tool, which is used to bend the electrode up or down, depending on the degree of its displacement.
One of the methods for checking the serviceability of the spark plug
When checking the condition of the spark plugs, you need to pay attention to the color of the deposit on the electrodes; a working spark plug will have a light grayish-brown deposit. If dry black deposits are noticeable on the surface of the electrode, this means that you need to check the engine power supply system, because it receives a mixture that is too rich.
Before installing a new or tested clean old spark plug, be sure to check the size of the electrode gap and, if necessary, set the desired gap. It is necessary to adjust the gap using the method described above, bending the side electrode; bending the central electrode or using a lever to bend the side electrode is strictly prohibited.
Only the manual method of installing spark plugs is allowed at the screwing stage, after which you can use a spark plug wrench. The final tightening of the spark plug should be done with a torque wrench; if it is not available, the spark plug should be tightened with a wrench 1/16 of a turn until its conical part comes into contact with the cylinder head.
Using a probe
Before checking the functionality of the spark plugs and determining their functionality, you need to unscrew them from the engine cylinder block. A special spark plug wrench will help in this matter.
To check the functionality, you can use a diagnostic tester or a piezoelectric probe.
Not every car enthusiast has such equipment, and often it is only available in auto repair shops, but there is a way out - use a homemade tool.
Video: spark plug diagnostics
A simple probe for registering the supply of a spark is made from a conventional piezo lighter. Disassemble it and remove the piezoelectric unit. Extend the wire coming from the block to 15 cm. The probe is ready. Now you can start checking.
This can be done using a manufactured probe. Connect the extended wire to the top contact of the spark plug and lean the piezoelectric unit itself against its body. Press the block button until it clicks and make sure that a clear spark appears between the contacts. This indicates its perfect serviceability.
Spark plug tester
You can't throw it away, clean it!
If you installed new spark plugs, which after a month of use began to cause interruptions in engine operation, you need to think about it.
We will assume that how to check the performance of spark plugs is known and the necessary procedures have already been completed. It remains to find out the root causes of this problem.
If it is not found and eliminated, then problems with the car will constantly arise, mainly with the engine.
There may be several reasons:
- excessive loads placed on the car engine;
- incorrect installation of spark plugs: incorrectly set gap, does not match the connector or machine;
- low-quality gasoline or oil is poured;
- spark plugs are very dirty.
It is necessary to check and adjust the gap between the electrodes at the same frequency as a complete replacement.
The gap must be adjusted by bending the side electrodes or using a cylindrical feeler gauge or a suitable piece of wire.
Spark plugs must be periodically inspected, changed and occasionally cleaned, if necessary. Cleaning can be done in two ways: mechanical and chemical.
Cleaning spark plugs at home
The mechanical method involves removing carbon deposits using some abrasive tools, such as a knife or files, but the performance may be deteriorated. When metal rubs against metal, scratches inevitably occur, which over time will heat up strongly and quickly, so you need to carefully clean it by wrapping the hard object in a cloth.
Chemical cleaning is more effective, but the process takes longer. First you need to degrease, wash in gasoline, dry and leave for 30 minutes. place in ammonium acetate solution. After the candle is removed from the solution, it must be cleaned with a soft brush, dried and screwed into place. In this case, you must remember to control the gap in the spark plugs.
Constantly monitor the engine's performance and remember how often you need to check the spark plugs. This will help ensure smooth operation of the car engine.
Source: http://AvtoMotoSpec.ru/remont-avtomobilya/kak-proverit-svechi-zazhiganiya-periodichnost-metodika.html
Checking and replacing spark plugs – Automotoguru
If the engine starts to run unstably and loses power, suspicion often falls on a faulty spark plug. This is especially true at idle speed. Increased fuel consumption also indicates that it is worth checking the spark plugs.
Reasons for spark plug failure
- Natural wear and aging (on average, their service life is 30-50 thousand km). If the spark plug fails very quickly, the reason may lie in low-quality fuel or oil with additives. Significant spark plug wear can occur when the engine detonates and/or overheats.
- The presence of a large amount of soot on the electrodes . Typically, this is the result of either an unbalanced fuel-air mixture or poor quality fuel.
- Presence of oil on the electrodes . In turn, the reason for this may be: excess oil in the engine, wear of piston rings, wear of pistons, cylinder block, valve guides. If the engine is equipped with a turbine, then it may be partially damaged.
- Varnish deposits . They appear due to the presence of additives in the fuel or oil.
- Slag deposits . They are the result of additives in the engine oil.
- Failure of the central electrode . This can happen due to an incorrectly set ignition. In addition, there may be deposits in the combustion chamber, valve malfunction, low fuel quality, or incorrect tightening torque of the spark plug in the cylinder head.
- Melting candle . Typically, the electrodes straighten out due to the fact that there are deposits in the combustion chamber that constantly self-ignite. Also, a similar situation can arise due to faulty valves or the use of low-quality fuel.
- Wear of the spark plug connector . This may occur due to aging contacts or overheating.
How to check spark plugs
Spark plugs with high voltage wires
Method 1. The simplest test method is to remove the wires from the spark plugs one by one with the engine running.
In this case, you need to listen closely to the operation of the engine - if, after removing the wire from the spark plug, the rumbling of the engine does not change, then it is the spark plug that has failed.
It may have to be replaced, but it is worth carefully inspecting the faulty spark plug - it may need to be cleaned enough.
Method 2. Another fairly simple, but more effective method. You need to unscrew the spark plug, put a wire on it, put the spark plug on the valve cover and turn it with the starter. On a working spark plug, a spark will be visible, optimally clear and bright.
"Gun" for checking spark plugs
Method 3. Checking spark plugs using a “gun”. Spark plugs can also be checked using a special “gun”, which is sold in automotive stores. The spark plug needs to be inserted into a special hole and see if there is a spark. If it is not there, the candle can be thrown away. But if there is a spark, it is still not a fact that it will work in the well under a different pressure.
Method 4. Essentially, the principle is the same as in the previous method. You can only make a device for checking a candle yourself, having a piezo lighter on hand.
The wire that comes from the piezoelectric module must be extended and then attached to the tip of the removed spark plug. The piezoelectric block itself must be pressed against the body of the candle and the button on the block must be pressed.
If there is no spark, the spark plug needs to be replaced.
Checking the spark plug under pressure in a self-propelled device
Method 5. Checking the spark plug under pressure. You can check the spark plug under pressure using a simple device using a 20 cc medical syringe and a suitable goujon. Thus, it will be possible to reproduce the pressure on the spark plug close to the working one, and, accordingly, carry out a more accurate test.
How to check spark plugs under pressure with your own hands
How to check a spark plug with a multimeter
The correct answer is no. Unless you can determine if there is a short circuit in the spark plug. To do this, you need to touch the spark plug input with one wire, and the thread with the second. The spark should strike about 4 mm. Use a multimeter to check high-voltage wires.
Here's how to check your spark plugs. In some cases, the candle may still work. Perhaps it is enough to clean it or adjust the gap of the electrodes by bending them.
since the part is not the most expensive, to be sure, the suspicious spark plug can be replaced.
It is also worth taking into account that spark plugs have their own replacement interval. The frequency of replacing spark plugs varies depending on the engine, but on gasoline engines they are changed approximately every 30,000 km. mileage
Source: https://avtomotoguru.ru/proverka-i-zamena-svechey-zazhiganiya/
Honda Civic. Checking the condition and replacing spark plugs
Checking the condition and replacing spark plugs
| If the original spark plugs are reinstalled on the engine after checking their condition, they must be screwed strictly into the previous cylinders and make the appropriate markings. |
All car models discussed in this Manual are equipped with transverse engines. Spark plugs are installed at the top of the engine.
Tools needed when replacing spark plugs
| 1. Spark plug head - Equipped with a special soft liner that eliminates the possibility of accidental damage to the porcelain insulator when turning the spark plug out. 2. Torque Wrench - Although not required, provides reliable assurance that the spark plugs are being tightened to the correct torque. 3. Ratchet drive - Used in conjunction with a spark plug head and a torque wrench. 4. Extension - Depending on the model and its accessories, access to the spark plugs may be limited to varying degrees, so the use of extensions of the appropriate shape and design will greatly facilitate the procedure. 5. Tool for measuring and adjusting the interelectrode gaps of spark plugs - Several types of such tools are available; make sure that the tool is equipped with a probe that matches the size of the spark plug gaps of your car. |
In most cases, to replace spark plugs, you need a special spark plug head (with a soft liner inside) complete with a ratchet drive, as well as a set of key drive extensions and tools for checking and adjusting the interelectrode gaps (see.
illustration above). To safely disconnect the explosive wire tips from the spark plug shanks, a special tool is also available, although its use is not strictly necessary.
Using a torque wrench will ensure the correct spark plug torque is achieved.
It is best to always keep a set of replacement spark plugs in your car with a correctly adjusted interelectrode gap. When purchasing new spark plugs, make sure that they meet the parameters of your car's engine.
The necessary information is given in the Specifications for this Chapter, as well as on the VECI label attached under the hood (in case of discrepancies, preference should be given to the requirements of the latter).
|
Spark plug condition map
| Normal condition of the spark plug Symptoms: Gray-brown color and slight wear of the electrodes. The glow number of spark plugs corresponds to the type of engine and its general condition. Recommendations: When replacing spark plugs, install spark plugs of the same type. |
| Wear Symptoms: Rounding of electrodes with slight accumulation of deposits at the working end. The color is normal. Leads to difficulty starting the engine in cold wet weather and increased fuel consumption. Recommendations: Replace the spark plugs with new ones of the same type. |
| Carbon deposits Symptoms: The presence of soot indicates an over-rich fuel-air mixture or weak spark intensity. Causes misfires, makes starting difficult and leads to engine instability. Recommendations: Check if the air cleaner is clogged, if the fuel level in the float chamber is too high, if the air damper is stuck and if the contacts are too worn. Try using plugs with a longer insulator, which increases resistance to fouling. |
| Ash Formation Symptoms: Soft brownish deposits on one or both spark plug electrodes. The source of their formation is the additives used for oil and/or fuel. Excessive buildup can cause the electrodes to insulate and cause misfire and rough running of the engine under acceleration. Recommendations: If deposits accumulate quickly, change the oil seals, which will prevent oil from entering the combustion chambers. Try changing the brand of fuel. |
| Oiling Symptoms: Oiling of the spark plug is caused by wear of the oil seals. Oil enters the combustion chamber through worn valve guides or piston rings. Causes misfires, makes starting difficult and leads to engine instability. Recommendations: Carry out mechanical restoration work and replace the spark plugs. |
| Short circuit of electrodes Symptoms: Waste combustion products enter the interelectrode space. Solid deposits accumulate, forming a bridge between the electrodes. Leads to ignition failure in the cylinder. Recommendations: Remove deposits from the interelectrode space. |
| Overheating Symptoms: Porous, white insulator, electrode erosion and absence of any deposits. Leads to a reduction in the service life of the spark plug. Recommendations: Check whether the heat number of the installed spark plugs meets the requirements of the Specifications , whether the ignition timing is set correctly, whether the fuel-air mixture is supplied too lean, whether there are any vacuum leaks in the intake pipeline and whether the valves are jammed. Also check the coolant level and whether the radiator is clogged. |
| Ignition too early Symptoms: Electrodes are melted. The insulator is white, but may be dirty due to misfires or foreign particles entering the combustion chambers. May cause engine failure. Recommendations: Check the heat number of the installed spark plugs, the ignition timing, the quality of the mixture (is it too lean), whether the cooling system is clogged and whether the lubrication system is functioning normally. |
| Conductive Gloss Symptoms: The insulator has a yellowish color and a polished appearance. Indicates a sudden increase in temperature in the combustion chambers during sudden acceleration. In this case, ordinary deposits are melted, taking on the appearance of a varnish coating. Leads to misfires at high speeds. Recommendations: Change the spark plugs (colder ones, while maintaining your driving style). |
| Detonation Symptoms: Insulators may become chipped or cracked. Damage to the insulator can also be caused by inaccurate spark plug gap adjustment techniques. May cause damage to pistons. |
| Mechanical Damage Symptoms: May be caused by foreign material entering the combustion chamber or may occur when the piston hits a plug that is too long. Causes cylinder failure and piston damage. Recommendations: Remove foreign particles from the engine and/or replace. Since the service life of spark plugs is usually 15,000 km, it is enough to clean them every 8,000 km. |
Source: http://sinref.ru/avtomobili/Honda/001_Honda_Civic_1994_2000/051.htm
How to check spark plugs yourself
In an ideal world, spark plugs should be changed every 35-45 thousand kilometers. Gasoline is cheap, all drivers follow traffic rules, pedestrians do not run when red lights are on, and the roads are smooth even in the most remote village.
Unfortunately, we do not live in an ideal world - reality constantly strives to give us another problem. Then winter has suddenly arrived and you need to change your summer tires. Then the car's spark plugs are acting up.
In a situation where the car starts to have difficulty starting or the engine begins to idle nervously, you will have to crawl under the hood and diagnose the spark plugs.
Those who like to give up on the problem should think about whether they should joke with the ignition system and wait until it goes away on its own? A car is not a living organism and cases of miraculous healing do not happen to it even in fairy tales! Therefore, if the engine begins to “trouble”, you need to pull yourself and the spark plug tester together and get to work. In addition to checking the spark plugs, you can perform another useful manipulation - check the compression in the engine.
Spark plug diagnostics - eliminating the root cause
All spark plugs usually do not fail at once. Usually the cause of interruptions is one or two faulty spark plugs. Therefore, the first diagnostic measure is to find the one that has stopped working.
The service life of spark plugs for ordinary cars operating in difficult conditions (for example, on the roads of Russia, Ukraine) corresponds to a mileage of 25-35,000 km. That is, if the vehicle is used frequently, spark plugs need to be replaced at least 2 times a year - before the start of the spring season and at the beginning of September.
However, the characteristics of spark plugs are not the same for all cars; for example, the VAZ ignition system is too hot and has too powerful a spark discharge. For their drivers, a common problem is that there is no spark from the ignition coil. On such models, electrodes, spark plugs, and coils quickly deteriorate and require replacement every 15,000 km.
Even the blonde from the jokes can check the spark plugs, so the excuse: “I don’t know how to check the spark plug” cannot be taken seriously.
Simple ways to check spark plugs
How to check the spark plugs yourself, let's look at different methods.
The easiest way to check a car's spark plugs is for the driver to alternately remove the wire running from the spark plug to the distributor.
After the wire is removed, you need to listen to the rumbling of the engine at idle. If its rhythm has not changed, then this particular candle has failed and needs either repair or replacement.
It should be said right away that replacing is easier than repairing. On the other hand, spark plugs often fail due to low-quality gasoline or improper initial installation. Since not everyone has a device for checking spark plugs, we will describe ways to check the system that do not require its use.
The second method is no less simple and effective. We remove the wire from the spark plug itself and bring it closer to the cylinder block. Based on the resulting spark, we can judge whether the ignition system is working well.
Rough engine operation may be due to a crack in the wire insulation. Therefore, you need to check their integrity. Turn off the car and carefully, preferably with a magnifying glass, inspect the high-voltage wires. Once you find a crack, you can simply wrap the wire with electrical tape. Although it is better to replace it immediately.
The reason for the wear of spark plugs is that they cannot be thrown away, they must be cleaned!
If a spark plug hasn’t worked for even a month and has already caused interruptions in engine operation, it’s worth thinking about. And try to find the reason for this state of affairs. Otherwise, you will have to constantly tinker with the car, in which one or another part will alternately begin to fail. And the engine is no joke!
The reason may lie in:
- excessive loads to which the car engine is exposed;
- unsuccessful installation: the gap in the spark plugs is incorrectly set, the spark plug does not fit in the connector or is too weak for the vehicle;
- low quality gasoline and oil are used;
- Heavy contamination of the spark plugs is allowed.
It is necessary to adjust the gap between the electrodes with the same frequency as a complete replacement of spark plugs. Adjustment is carried out by bending the side electrodes using a cylindrical probe or a piece of wire.
But the spark plugs need to not only be changed, but also cleaned at least occasionally. Cleaning is carried out in two ways: mechanical and chemical.
Mechanical involves the use of sharp objects to remove carbon deposits from a spark plug, but this may impair the performance of the spark plugs. Because the metal leaves scratches, which subsequently begin to heat up stronger and faster. Therefore, you need to clean it carefully - wrapping a screwdriver or an awl in a piece of cloth.
The chemical method is more effective, but takes longer. The candle is degreased, washed in gasoline, dried and immersed in an ammonium acetate solution for half an hour. After which the candle needs to be cleaned with a nylon thread or a soft hair brush, dried and put in place. Don't forget to adjust the gap in the spark plugs!
Video - “Spark plug spark power”
Source: http://autoremka.ru/dvigatel/kak-proverit-svechi-zazhiganiya-samomu.html
How to properly replace spark plugs?
The spark plug plays a vital role in igniting the combustible mixture in an internal combustion engine.
It doesn’t matter whether you own a new car or not, spark plugs require periodic inspection, cleaning and replacement.
In modern cars from foreign manufacturers, the engine is covered with a plastic partition, but don’t let this scare the car owner - replacing the spark plugs yourself is also possible in this case.
Spark plug selection
Choosing a new spark plug for a car owner is a responsible task, since the quality of engine operation will largely depend on it. Pay attention to the manufacturer's brand and do not hesitate to check the functionality of the elements with the seller.
Especially in car markets or in small shops where faulty spark plugs are sold under the guise of new ones. Large car dealerships that value their reputation offer spark plug testing themselves.
They use catalogs to simplify the selection of spark plugs for your car model.
If you are new to choosing candles, focus on two main components - geometric shape and heat rating. Everything is clear about the shape - minimal differences from the previous shape, otherwise you won’t be able to screw it in or the electrodes won’t reach the chambers in the engine. A spark plug that is too long is also detrimental to the engine, since it will damage either the spark plug or the internal combustion engine.
The heat number displays the heating mode of the element - with a low value, the spark plug quickly overheats. The recommended parameters are specified in the service book for the car.
The classic version of a candle is a ceramic body, a metal glass with a carving and two petals at the bottom.
There are candles with a large number of petals, which are easy to recognize - there is a central electrode in the middle, which is surrounded by three or four electrodes on the sides.
This allows the fuel in the cylinder to ignite evenly and burn well. In addition, engine power increases, as do environmental performance indicators.
Safety precautions when replacing spark plugs
There are no special safety rules for replacing ignition elements in a car. It is recommended to start it with a cooled engine to avoid burns.
Since spark plugs operate at extremely high temperatures, it is better not to try to replace them immediately after stopping the car, but to wait two to three hours for the engine to finally return to normal temperature.
Preparing to replace spark plugs
For those who have never changed spark plugs, it will not hurt to know that there is nothing complicated in this procedure - the main thing is to do it carefully, in the correct order of actions.
The first step is to find candles. On engines with four cylinders they are usually located on one side of the internal combustion engine or on top, in V8 engines - on the side so that there is one spark plug for each cylinder. When looking for spark plugs, look for wires surrounded by black insulation. Once you find them, you will easily find what you are looking for.
The next step will be preparing the necessary tools. Prepare a car key with a special attachment for working with spark plugs and a couple of new ignition elements.
To make the job easier, take a can of compressed air, a rag and technical alcohol.
If in the future you do not want problems with unscrewing the spark plugs at the next replacement, apply a little aerosol lubricant to the threads before screwing in the spark plugs.
To prevent dirt from penetrating inside the cylinder, it must be removed before removing the old spark plug, so clean the engine near the ignition element before starting the procedure. Debris and dust are removed using compressed air, which makes cleaning much easier. If there is a lot of dirt, use a rag soaked in industrial alcohol.
Removing old spark plugs
The spark plugs themselves are connected to the block that distributes the ignition by wires that need to be disconnected. To do this, grab its cap and pull with slight force until the wire is disconnected.
Remove the wire from only one spark plug to avoid getting tangled, since they are connected by special connectors that cannot be mixed up when connecting. Put the spark plug attachment on the key, secure it on top of the element and twist it counterclockwise.
After removing the candle, you need to clean the dirt from the place where it stood. To do this, you will need a rag soaked in industrial alcohol.
Be sure to inspect the spark plug electrodes. Make sure that the space between them is not clogged with dirt. Possible problems with the rings are indicated by an excessive amount of oil on the spark plug. In this case, it is a good idea to show the car to a mechanic. If the old spark plug has a brownish tint, there are no problems with the engine.
Installing new spark plugs
Before installation, be sure to visually compare the old spark plug and the new element. They must match. The size of the thread on the spark plug and its pitch must also be identical, as well as the gaps on the ignition elements.
Lubricate the threads with a small amount of lubricant, but do not get it on the electrodes themselves, as this may damage the performance of the spark plug. After this, twist the element clockwise by hand until you have enough strength.
Use a wrench to tighten, but do not overtighten, as this can also damage the spark plug. Make sure that the washer on the spark plug is below the level of the head on the engine.
After installing the spark plugs, attach the previously removed high-voltage wires to them. The caps should fit tightly. To make sure of this, pull the wire towards you. It should not easily jump off the installed spark plug. After completing the procedure with one, repeat it with the rest of the candles.
Every car enthusiast can carry out the procedure for replacing spark plugs, but if you are not confident in your abilities, any service station will readily undertake this, so the choice is yours - change it yourself or trust a car mechanic.
Source: https://xn--80aqfgda6as.xn--p1ai/blog/zamena-svechey-zajiganiya
How to determine the condition of a spark plug
Spark plugs are an integral element of the ignition system and serve to ignite the fuel-air mixture in the engine cylinders from an electric spark that is formed between the electrodes of the spark plug. Spark plugs must be changed every 30-90 thousand km, which directly depends on the operating conditions of the engine, the type of spark plugs installed and the materials used to make them.
We also recommend reading the article on how to choose spark plugs based on your car make. From this article you will learn about the features of selecting spark plugs according to the car model, as well as choosing the optimal material for making spark plugs for a specific engine.
Why is it best to change spark plugs ahead of schedule?
Engine malfunctions indicate the need to check the spark plugs. As already mentioned, spark plugs last from 30 thousand km, but this is only a theory that is based on ideal operating conditions of the internal combustion engine. In practice, the average service life of budget single-electrode spark plugs is no more than 15-20 thousand km. mileage
The reduction in the planned life of spark plugs is greatly influenced by the quality of domestic fuel, city driving at low speeds, and frequent and long idling of the engine.
For this reason, even the most expensive multi-electrode iridium or platinum spark plugs are recommended to be changed every 15-20 thousand km. before the stated service life.
Also on sale may be fake spark plugs or low quality products that usually do not last even 10 thousand km.
Signs of faulty spark plugs
Let's start with the fact that a serviceable engine should operate stably, smoothly and steadily both at idle and under load.
Difficulty starting the engine, unstable engine operation at idle and while driving, increased fuel consumption, decreased power, the appearance of noise and vibration during engine operation is a list of the main symptoms that may indicate problems with the spark plugs.
Regular inspections are necessary to monitor the condition of the spark plugs. It is advisable to carry out this procedure in parallel with changing the oil during maintenance, that is, after 10-15 thousand km. As for the average driver who drives about 30 thousand km. for 12 months, in this case, conventional single-electrode spark plugs should be changed at least 2 times a year.
How to check spark plugs
Signs of contamination or failure of spark plugs appear in the form of interruptions in engine operation; an engine with dirty or problematic spark plugs will suffer.
This happens because all the candles usually do not fail at once. Interruptions begin in only one or two cylinders. The first step is to identify the spark plug that has failed.
There are several ways to check spark plugs:
- using a device or tester to check spark plugs;
- independent checking of spark plugs;
To check the spark plugs, you need to remove them, although there are also ways to diagnose spark plugs on a car. Before starting the procedure that involves removal, you should turn off the ignition and prepare a special spark plug or socket wrench. You will need a tool to unscrew the spark plugs.
Then you need to inspect the high-voltage armored ignition wires. These wires usually have special markings that contain information about the cylinder number.
If there is no such marking, you will need to mark the high-voltage spark plug wires yourself in an accessible way.
The next step is to remove the tips (caps) from the spark plugs. Please note that you should not pull on the high-voltage wire while performing this procedure, as this may damage the armor wire.
To remove it, you need to hold onto the tip itself. After removing the spark plug caps, you can unscrew the spark plugs using a wrench. V-twin engines will require a long drive wrench, similar to a torque wrench.
An extended collar will also work.
During removal, you should remember which cylinder each unscrewed spark plug corresponds to, since further inspection will allow you to determine possible malfunctions not only of the spark plugs, but also of the engine based on the condition of the spark plugs.
Checking the spark plugs should begin with a visual inspection and checking the condition of the insulator, as well as the electrodes. Cracks or melting, as well as other noticeable defects, are not allowed. Next, the candles are installed on a special stand or checked with a device.
As mentioned above, motorists also check the spark plug directly on the car or use a multimeter. We will talk about various verification methods below.
Checking spark plugs for spark
To check the spark plug for a spark, you need to disconnect the high-voltage wires that connect the spark plugs and the distributor breaker one by one. This must be done with the car running.
After removing the wire, listen to the engine. If the operation of the motor has not changed, then this means that it was possible to find the failed element.
If, after disconnection, the motor begins to operate even less stably, the test must be continued.
The next way to check the spark on the spark plugs is to remove the high-voltage wire, after which the spark plug is unscrewed.
Then the spark plug is inserted back into the armored wire cap and brought to the cylinder block. As a result, a clearly visible spark should appear on the spark plug, which will be accompanied by a characteristic crackling sound.
This method allows you to diagnose the operation of the ignition system, wire and spark plug.
As for checking the spark plug with a multimeter, this method is ineffective and can only detect a short circuit inside the spark plug. To check, one contact of the tester is applied to the spark plug base (threaded part), and the other to the spark plug inlet.
The resulting spark should penetrate 3-4 mm from contact to contact.
Let us add that it is more correct to check the high-voltage ignition wires with a multimeter. This device is capable of measuring the resistance of the wire, after which it should be compared with the nominal one.
A drop in voltage will indicate the need to replace the armor wire.
Another way is to check the spark plugs with a “gun”. Such a “gun” for checking candles is a testing stand that is available from candle sellers. This equipment allows you to test spark plugs under pressure, that is, their operating conditions in the engine are partially simulated.
Checking the spark plug on the stand is carried out as follows:
- the spark plug is inserted into the groove;
- then a special cap is put on it;
- then all that remains is to pull the trigger of the “gun” to check the spark plugs;
The appearance of a spark on the electrodes and the lighting of the warning light most likely indicates the serviceability of the spark plug, although this test method cannot guarantee full functionality.
The fact is that the pressure on the stand and in the engine is different. For this reason, a spark plug previously tested on a bench with a good spark may still not work after being installed on the engine.
If the spark plug initially does not work on the stand, then this element should be replaced due to an obvious malfunction.
How to clean the spark plugs yourself and set the gap between the electrodes
After removal and external inspection, the spark plug must be carefully cleaned of dirt, soot, carbon deposits and deposits. This can be done mechanically, using a brush that has medium-hard bristles. It is also possible to use an abrasive.
The mechanical method allows you to efficiently remove carbon deposits, but the performance characteristics of the spark plug usually become worse. This type of cleaning usually results in scratches, which then cause the spark plug to overheat. For this reason, it is necessary to clean spark plugs from deposits as delicately as possible.
You can also clean spark plugs chemically:
- the candle is degreased and washed in gasoline;
- then the candles are dried for 30 to 60 minutes;
- then the candles are placed in a solution of ammonium acetate for 30-40 minutes;
Once removed from the cleaning solution, the spark plugs are cleaned with a soft bristle brush and dried again for about 30 minutes. Cleaning heavily soiled spark plugs will be of lower quality compared to the mechanical method, and will also require more time.
The advantage is a reduced risk of mechanical damage. The completion of cleaning is to check the gap between the electrodes of the spark plugs. The gap between the spark plug electrodes is assessed after mechanical cleaning.
The gap normally should not differ from the 0.7 mm mark. The specified gap must be checked using a special feeler gauge. If the gap is different, it needs to be adjusted.
Adjusting the spark plug gap is performed with a special tool, and the process itself involves bending or bending the side electrode from the central electrode.
Let us add that bending the central electrode is prohibited, and bending the side electrode should be done with extreme caution.
Engine condition by spark plug color
The serviceability of the engine and spark plugs is determined by the color of the deposit that is present on the electrodes. We will not describe all possible options for diagnosing the engine condition by the color of the spark plugs, since this is the topic of a large separate article. We only note that a working spark plug normally has a light grayish-brown coating.
The appearance of black dry soot on the electrode indicates the need to check the fuel system of the internal combustion engine. Such deposits form when the engine operates on a highly enriched mixture. The spark plug can then be cleaned and screwed back into the engine for further use.
The presence of a white coating with a reflection on the spark plug electrode is evidence of overheating of the spark plugs. This can happen either due to incorrect selection of spark plugs according to the heat rating, or as a result of overheating of the engine or the spark plug itself. In the latter case, the electrode gap size should be checked.
Candles with a white coating cannot be reused; replacement will be required.
Installing cleaned or new spark plugs into the engine at the initial stage is done by hand. In other words, the candles need to be “baited” by hand, that is, carefully screwed into the candle wells without using a key.
If the spark plug is easily screwed into the thread, then the element can be tightened with a wrench until the conical part comes into contact with the cylinder head.
Remember, when tightening the spark plugs, it is highly advisable to strictly adhere to the tightening torque specified in the technical documentation for a specific engine type! Retightening the spark plug may lead to the need for subsequent repair of the cylinder head and other consequences. As for loosely twisted spark plugs, an under-tightened spark plug can cause engine malfunctions.
Tips and tricks
If new spark plugs quickly change color after installation, become overgrown with carbon deposits and again cause engine malfunctions, then the following options are possible:
- spark plugs are incorrectly selected;
- a counterfeit or defective product was purchased;
- the engine is operated on low quality gasoline or oil;
- there are engine malfunctions that quickly disable new spark plugs;
Finally, let us add once again that spark plugs, as well as high-voltage spark plug wires, are “consumables”, that is, they need to be completely changed at certain intervals. If the engine previously had a malfunction that simultaneously damaged the spark plugs, then after eliminating such a breakdown of the engine, it is recommended to also replace the set of spark plugs.
Source: http://KrutiMotor.ru/proverka-sostoyaniya-svechej-zazhiganiya/
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