How do they work and why are glow plugs needed in a diesel engine?

What kind of glow plugs install in the engine? This question is often asked by owners of cars with diesel engines, regardless of the time of year. After all, replacement is necessary not only when the spark plug has already completely or partially failed, but also according to the regulations. The question of which glow plugs to install is especially pressing for car owners during the cold season, when the air temperature drops significantly.

Choosing a good glow plug starts with determining its type. They are divided into metal and ceramic. The next stage in the selection is the choice of its manufacturer. Currently, products from different brands are sold on the market, so the answer to the question of which glow plug brand is better is quite complicated. At the end of this material there is a list of popular candles, compiled on the basis of reviews of the actual use of these products found on the Internet.

When to change glow plugs

Regardless of how good the glow plugs are, sooner or later the question of replacing them arises. Unfortunately, many car enthusiasts perform the replacement procedure only when the spark plug is partially or completely damaged. However, every car has regulations, according to which spark plugs must be changed periodically, regardless of their condition and performance. Typically, replacement is performed (for standard, non-ceramic glow plugs) every 25...30 thousand kilometers or once every two years, whichever comes first. And it is advisable to replace it in the fall, before the onset of cold weather. You can find additional information about the interval at which spark plugs need to be changed in the car manual or on the website of the manufacturer/its official representative in your region.

As for more technologically advanced ceramic spark plugs, their service life is much higher, more than 100 thousand kilometers (and some Japanese ones up to 240 thousand, according to the manufacturer). If only one glow plug fails, it is necessary to replace the entire set so that their resource is consumed equally and they have approximately the same performance characteristics.

How to start a diesel engine correctly

Diesel does not like haste - not only when driving, but also when starting. To ensure the engine starts confidently, let the glow plugs run a full cycle, and only then start turning the starter.

The glow plugs begin heating when the ignition is turned on, and their operation is indicated by a special indicator on the dashboard - a yellow spiral. The colder it is outside, the longer the glow cycle lasts. Wait until the spark plug indicator goes out before starting the engine. And in severe frost, you can do two warm-ups in a row: turn off the ignition after the first glow and immediately turn it on again to restart it. This will significantly increase your chances of a successful launch.

Consequences of untimely replacement

No matter how good the glow plugs are used in a particular car, sooner or later they will fail. Untimely replacement (that is, replacement not according to regulations) can lead to very sad consequences for the engine, and accordingly, this can result in expensive repairs for the car owner. Therefore, it is necessary to change these units on time.

So, if you drive on spark plugs alone for 50...70 kilometers, then the spark plug rod is corroded from the sealing cone to the thread, and even beyond the thread. This leads to the “accretion” of the spark plug body to the cylinder head body. Accordingly, when you try to unscrew it from its seat, it often breaks either in the thread area or immediately behind the hexagon. Because of this, a large piece of the spark plug remains inside the cylinder head, and removing it from there is very problematic. To do this, you need to dismantle the head and use additional machines and equipment (jig boring machine). To reduce the likelihood of such cases, it is recommended to lubricate the spark plug threads with a special lubricant.

The second common problem associated with long-term use of a glow plug is that the heating element itself may fail. Moreover, failures can be very different. For example, it can burn out and fall into the combustion chamber. And this can lead to very serious consequences, such as destruction of the piston, destruction of the valve mechanism and other critical and expensive engine elements.

Another option for a heating element to fail is when it “swells up” in the shape of a pear. This leads to the fact that when the spark plug is removed from its seat, such a “pear” breaks off and falls into the engine cylinder. The situation is similar to that described above.

Another common problem associated with replacing glow plugs with diesel is caused by incorrect tightening torque when installing the spark plug. Most often this is expressed in the fact that the technician who installed it did not use a torque wrench, but chose the tightening torque “by eye,” usually exceeding the required value. Often, in this case, the spark plug body breaks and a microcrack appears in it. The spark plug continues to work normally, but the process of corroding the metal begins at the fractured area. And this leads to the fact that when the spark plug is removed from its seat, it usually breaks precisely at the fracture point formed. As a rule, the value of the corresponding tightening torque is about 15...20 Nm (it differs for different cars, so look for additional information in the car manual). Tightening must be done using a torque wrench.

If the glow plugs on your car have been running for over 30...40 thousand kilometers, and they were installed without using a torque wrench, then it is better not to dismantle them yourself, but to seek help from a specialized service. In such organizations, glow plugs are dismantled using special vibration pullers, which not only directly unscrew the spark plug, but also transmit vibration to its body, thereby loosening it in its seat and preventing breakage of its body. Vibration neutralizes the effect of rust, which causes the spark plug to stick to the body.

The principle of switching on a diesel engine

The fuel-air mixture, which is under pressure in the cylinder, is heated to 900°C.
To ensure fire conditions, the structure is highly durable. The combustible mixture is ignited by the compression ratio, and not by the spark plug. At ambient temperatures below plus 5°C, down to severe frosts, the combustion chamber requires forced heating using ceramic or pin glow plugs. The glow plug in a diesel engine is capable of heating the injection zone to 1000°C in a matter of seconds. When the diesel engine is turned on, these devices operate until the coolant temperature reaches plus 75°C.

Due to the increased demands of environmentalists, thanks to their unique properties, spark plugs begin to function at idle speed. The design of these parts helps reduce the amount of harmful emissions from a diesel engine into the atmosphere.

Starting a diesel engine: differences from gasoline engines

A diesel engine starts completely differently than a gasoline engine. Volatile gasoline, even at a temperature of -40° C, is ready to ignite from one spark, which is created in the cylinders by spark plugs. Due to its low volatility, diesel fuel - even winter fuel - needs the same 40 degrees for ignition, but with a plus sign (and summer fuel - +62° C). It’s not for nothing that diesel fuel is called heavy fuel.

The high temperature required for diesel combustion in the cylinder is created by air compression by the piston. Like any gas, air is compressed reluctantly, but its pressure and temperature increase. When an injector injects a portion of diesel fuel, it ignites on its own from contact with hot compressed air - because of this, it is often said that a diesel engine is started by pressure or explosion. Old diesel engines, not equipped with electronic injection and sensors, can easily operate without a battery, since the ignition of the fuel in the cylinders occurs mechanically, without any sparks or spark plugs.

But the diesel idyll is destroyed by Mother Nature: when the temperature drops to sub-zero temperatures, the air compression in the cylinders is no longer enough to heat the fuel until it ignites spontaneously. Therefore, it is impossible to completely abandon spark plugs in a diesel engine. It’s just that spark plugs are needed here not to ignite the fuel-air mixture, but to heat it.

What to look for when choosing

In order to answer the question of which glow plugs are best for diesel, you need to decide on what characteristics you need to make your choice. There are several criteria.

Material of manufacture

Comparison of the glow of metal and ceramic glow plugs

Currently, glow plugs are divided into two main classes based on the material used. The most common and cheapest are metal ones, they are also called pin ones. They have a metal shell made of a resistant alloy of iron, chromium and nickel. Their heating element is insulated from the body with thermally conductive powder (usually magnesium oxide). This material not only insulates the spiral, but also reliably protects it from harmful vibrations that can mechanically damage it.

Another type of glow plugs are the so-called ceramic ones. Their heater is made of a refractory ceramic alloy, which is capable of withstanding operation at maximum temperatures for a long time while maintaining the specified performance characteristics. Their protective shell is made of silicon nitrite. This is a ceramic material that has extremely high thermal conductivity. The design of the ceramic candle allows it to warm up to operating temperature in a record time - about 2 seconds. Thus, the driver can often start the engine immediately without waiting for a warm-up time.

Interestingly, only ceramic glow plugs meet the requirements of Euro-5 and Euro-6 environmental standards, since they ensure optimal combustion of diesel fuel almost from the first seconds. That is, with minimal emissions, with a minimal amount of carbon monoxide.

Many car enthusiasts cannot make a choice: should they buy ceramic or metal glow plugs for their car? There is no clear answer in this case. Ceramic candles have much higher performance characteristics and need to be changed extremely rarely. However, they have a significant drawback - high price. Therefore, it makes sense to install them on new and/or expensive imported cars that are demanding on individual engine parts, in particular, glow plugs. In other cases, there is no point in overpaying, and you can use standard metal candles. However, their selection must be made based on additional parameters.

Number of spirals

The most common are candles with one heating coil. They belong to the first generation. Their heating time is about 10 seconds. However, recently spark plugs with two incandescent coils have become increasingly popular. They are designed to last longer on a cold engine. The second spiral is the so-called regulatory one. Its use allowed us to achieve two advantages. The first is a short warm-up time, about 2...5 seconds. Secondly, the load on the main spiral is reduced, which extends its service life.

The use of self-regulating spark plugs (with two spirals) promotes better combustion of diesel fuel, reducing the amount of carbon monoxide and other harmful substances into the atmosphere. European environmental standards Euro-4, Euro-5 and others strictly regulate these requirements. This is what caused the appearance of spark plugs with two filament coils.

Therefore, before choosing glow plugs, you need to further clarify in the documentation which type of spark plugs is suitable for your car’s engine. And purchase the appropriate unit. Please note that the geometric dimensions, seating and fastening elements for first and second generation candles may be the same. And they will differ only in the number of spirals.

They cannot be replaced with each other. The fact is that a candle with two heating coils lasts longer in a heated state. That is, it is designed to operate in long-term thermal conditions. And if instead of it you install a candle with one incandescent spiral, it will simply burn out. It is this fact that often becomes the reason that some car enthusiasts very often burn out new spark plugs within a short period of time after installation. The situation is aggravated if the ambient temperature outside is significantly below zero (severe frost). In this case, if instead of a double-stranded glow plug a single-stranded one was installed, then the likelihood of its rapid failure increases significantly.

There is another type of spark plugs - for easier starting. Their design involves the use of one spiral, but with variable resistance. Its value changes as the engine warms up, which ensures not only easy engine starting in the cold season, but also less load on the spark plug and the vehicle’s electrical system as a whole.

Accordingly, when choosing a particular glow plug, you need to know not only the geometric dimensions of the plug, but also its characteristics. And it’s better to choose from the electronic catalogue. Ideally, of course, buy original spare parts, but due to the fact that most of them are unreasonably expensive, you can also find cheaper analogues.

Number of poles

Modern glow plugs can have one or two connection poles. Single-pole connection is simpler. In this case, the “plus” of power is supplied to the spark plug, and the “minus” (ground) is output to the housing. More complex double-pole spark plugs have separate contacts for plus and minus.

Voltage consumption

Various glow plugs are available for different operating voltages - from 6 to 24 Volts. For most passenger cars this value is 12 Volts. There are glow plugs with an afterglow function. They are mounted complete with additional electrical resistance. This ensures that the spark plug operates at maximum power before starting the engine, and after starting the engine, this power is reduced in order to reduce the load on the adjusting spiral.

Electrical resistance

As a rule, the resistance value of the spiral is in the range of 0.5...1.8 Ohms. It depends on the specific candle model, as well as its type. So, for ceramic candles the corresponding value is lower, and for metal candles it is higher. The value of electrical resistance directly affects the efficiency of the spark plug.

Operating temperature

On average, the operating temperature of glow plugs is within the range of +1000°С…+1350°С. This depends on the specific brand of candle. Metal samples will have a lower temperature, while ceramic samples will have a higher temperature. The choice of temperature conditions must be carried out in accordance with the requirements of the car manufacturer. Typically, the documentation indicates a specific temperature range for glow plugs.

Standard Features

We are talking about geometric dimensions and other technical parameters. In particular:

• diameter and pitch of fastening thread: from M10×1.0 to M18×1.5;
• key size: 12, 14, 17, 21 mm;
• cone slope: 63°, 93°, 123°;
• total length: 58…137 mm;
• working part length: 17…35 mm;
• working part diameter: 4…6 mm.

Information about spark plugs suitable for a particular engine can be found in its technical documentation. And make a choice, be sure to take these parameters into account.

Useful tips

1. Before the onset of the cold season, the glow elements should be checked regardless of whether the diesel engine starts well or poorly.
2. Checking on a diesel engine by assessing the spark is recommended only for older cars. You should not test heating solutions in this way on a “fresh” model, which is equipped with a complex electronic engine control system.
3. If a malfunction is detected, it is optimal to replace the entire set, rather than one or two failed elements.
4. Try to purchase products from well-known manufacturers, since cheap solutions have a noticeably shorter service life and often demonstrate low efficiency of the heating element.

Finally, we would like to add that in order to reliably start a diesel engine in winter, it is necessary to correctly select, charge and maintain a diesel battery, refill high-quality diesel fuel according to the season, and use anti-gels if necessary. Also, in the case of diesel engines, it is advisable to install a diesel fuel pre-heater or a Webasto-type engine pre-heating system.

Sources

• https://avtodvigateli.com/detali/svecha-nakalivaniya-dizelya.html
• https://HyperAuto.ru/articles/poleznaya-informaciya/zimniy-zapusk-dizelya-svechi-nakalivaniya/
• https://my-zenit.ru/remont/kak-proverit-svechi-nakala-ne-snimaya
• https://service-vao.ru/articles/zamena-svechej-zazhiganiya-dizelnogo-dvigatelya/
• https://voditelauto.ru/%D1%81%D0%B2%D0%B5%D1%87%D0%B8-%D0%BD%D0%B0%D0%BA%D0%B0%D0%BB% D0%B0-%D0%BD%D0%B0-%D0%B4%D0%B8%D0%B7%D0%B5%D0%BB%D0%B5/
• https://mashinapro.ru/1819-kak-proverit-svechi-nakalivaniya.html
• https://AutoTopik.ru/diagnostika-neispravnostei/1535-proverit-svechi-nakala-na-dizele.html
• https://InfoSort.ru/remont-avtomobilya/385-kak-vyibrat-svechi-nakalivaniya-dlya-dizelya-otzyivyi-xarakteristiki-i-sovetyi-speczialistov
• https://KrutiMotor.ru/kak-proverit-svechi-nakala-na-dizele/

Which glow plugs are best to buy?

This section provides a list of glow plugs that are best to buy for your car in order to ensure not only normal heating of the fuel before starting, but also to be sure of their durability. It is worth noting that the list is not of a commercial nature and does not endorse any of the brands featured on it. The rating is based on reviews of their operation that were found on the Internet.

NGK

The Japanese company NGK Spark Plug Co., Ltd is the world's leading manufacturer of glow plugs for various types of automotive equipment. NGK glow plugs are designed to operate in the lowest temperatures, so they can be used even in the extreme north. The advantages of NGK candles include:

• the company's many years of experience in the production of glow plugs for a wide variety of equipment, and constant updating of the assortment due to new developments;
• the company produces glow plugs for more than 260 models of European automobiles (which is about 86% of the market);
• the highest quality of manufacture and operation of NGK spark plugs;
• unique design of the spark plug body, which implies the use of a protective layer against corrosion, effective heat transfer, gas-tight seal, housing strength, high resistance to deformation, high reliability;
• production of various types of candles, including those with a metal rod and ceramic high-temperature glow plugs, capable of developing a temperature of +1350°C, which the candle reaches in two seconds.

Reviews and tests found on the Internet suggest that, in fact, NGK glow plugs are one of the leaders in this market. They have extremely high performance characteristics. However, they have two disadvantages. The first is the high price. However, in many ways it is justified, since the candles are guaranteed to work reliably and for a long time. The second disadvantage is the large number of counterfeit products. Accordingly, you must carefully check the product before purchasing.

The range of NGK glow plugs is extremely large. However, to facilitate the selection of a particular spark plug for a specific car and engine, the company’s specialists have developed an electronic catalog with which you can quickly select the required element. You can easily find this resource on the Internet. The selection procedure takes just a few seconds. There, the catalog provides the spark plug number by article, with which you can buy a glow plug in any online store.

Denso

DENSO Corporation is another world leader that produces glow plugs, among other things. On many Japanese and European cars, its products are installed as original ones during the car assembly line. Currently produces more than 130 models of glow plugs, which can be used in 2600 applications. This provides about 98% of the automotive market in Europe, Asia and the USA. Therefore, you can choose a DENSO glow plug for almost any car with a diesel engine. At the same time, the candles comply with international quality standards ISO TS 16949, ISO 14001 and OHSAS 18001.

Produced candles are divided into the following types:

• with one spiral;
• with two spirals;
• with prolonged post-start heating;
• ceramic candles;
• instant heating candles.

All Denso glow plugs are designated as DG-ХХХ, where ХХХ is three digits. So, they mean:

• 001...010 - top 10 best-selling candles, about 46% of European sales;
• 101...198 - other candles, about 50% of European sales;
• 211…246 — glow plugs for OE TOYOTA applications (except ceramic);
• 301…311 — ceramic glow plugs (including OE TOYOTA applications);
• 400…401 — glow plugs with liquid cooling (including TOYOTA applications);
• 501…502 - glow plugs for Mazda;
• 700...703 - new applications after 2009.

Numerous reviews and tests show that original, genuine Denso glow plugs are indeed distinguished by very high quality workmanship, high performance characteristics and a long service life. Therefore, it makes no sense to talk about their advantages, everything is obvious. As for the disadvantages, there are again two of them: the high price and a large number of fakes. You can also choose an original candle from the catalog available on the Internet. The main thing is to buy a Denso glow plug in a store that sells original products.

Many car enthusiasts are interested in the question of which glow plugs to buy - NGK or Denso? In fact, it is impossible to specifically answer this question, since both of these manufacturers produce candles of the highest quality. Therefore, when choosing, it is necessary to consider specific models, compare their performance characteristics and prices. If you purchase original products of one or another brand, the car owner is guaranteed to have no problems with the operation of these spark plugs.

Beru

The German company Beru produces its own glow plugs under the brand of the same name. Original products are of high quality and wide range. Many owners of cars with diesel engines buy Beru glow plugs because they are slightly cheaper than the NGK or Denso mentioned above, despite the fact that their quality is high. Therefore, they can be installed in almost any diesel engine, of course, taking into account the correct selection for a particular engine.

Currently, Beru glow plugs are divided into the following subtypes:

• GN - for modern cars equipped with a three-phase glow system;
• GF - for engines with large displacement, direct injection of diesel fuel, flare type;
• GH - rod or spiral candles, used for additional heaters;
• GD - glow plugs for tractors and cars of older generations;
• GV - two-phase glow plugs, used for older generation vehicles.

Reviews found on the Internet (mainly on numerous forums) suggest that Beru glow plugs are an excellent solution for any car with a diesel engine. The range of manufactured models allows you to select spark plugs for most European cars. For many brands, this product comes as original from the assembly line. Therefore, they are definitely recommended for purchase by both ordinary car enthusiasts and technicians who repair cars on an ongoing basis.

Febi

The Febi brand, under which glow plugs are sold, belongs to the German concern Ferdinand Bilstein GmbH + Co. KG. Therefore, original spare parts bear the Febi or Febi Bilstein JR logo. The company produces and also packages ready-made spare parts. The quality of original products is always confirmed by a certificate with the number DIN ISO 9002, and is also verified by the independent association TUV. Since 1998, the company has been one of the largest packagers of spare parts for the secondary automotive market in Europe.

The range of Febi glow plugs produced is very wide. Currently, you can choose a spark plug for almost any European car. On the Internet you can easily find electronic catalogs with which you can select a spark plug model for a specific brand and a specific engine. Information about the corresponding articles is also provided there. The selection process takes just minutes.

Please note that Febi packages often contain both BOSCH and NGK, as well as counterfeit spare parts of Chinese origin. In particular, those produced in China by unknown manufacturers. However, the quality of these products is very low. Therefore, when purchasing, always pay attention to both the manufacturing quality of the candle itself and the quality of packaging (printing, errors in the description, and so on). Original products always bear the inscription Febi Germany. If there is no such inscription, this is a fake.

Reviews found on the Internet about Febi glow plugs are mostly positive. Therefore, they can be definitely recommended for use on various cars. The main problem is only the presence of a large number of fakes.

Kager

The Kager brand, under which glow plugs of the same name are produced, belongs to the Polish company Fota. Its products are manufactured in several factories in the European Union and meet all the quality standards of this state association. The range of candles produced is quite wide. Under this brand you can buy glow plugs not only for European cars, but also for many Asian (mainly South Korean) cars. Many online stores have an electronic catalog where you can choose a spark plug for a specific car make and engine.

Kager glow plugs have a good price-quality ratio. They can be installed on both budget cars and business class cars. Reviews about them on the Internet are mostly positive. Therefore, they can definitely be recommended for purchase.

BOSCH

The world-famous company BOSCH currently produces three lines of glow plugs - Duraterm, Duraterm@High Speed, DuraSpeed. All of them are made of ceramics, so they have very high performance characteristics. Let's look at their features in order. Let's start with Duraterm:

• operating voltage - 11 Volts;
• Patented integrated filament control system speeds up the preheating phase;
• engine starts in less than 4 seconds;
• residual heat is about 3 minutes;
• when warming up, fuel consumption is minimal;
• the use of BOSCH Duraterm glow plugs reduces harmful emissions by approximately 40%, which increases the environmental friendliness of the engine;
• The glow plug increases engine life by improving fuel combustion.

Duraterm@High Speed ​​Glow Plugs:

• spark plugs are designed for low-voltage systems and operate with a voltage of 4.4 or 5 Volts;
• heating time to temperatures above +1000°C - less than 3 seconds;
• residual heat time - up to 6 minutes;
• using low voltage to operate the spark plug reduces the load on the vehicle’s electrical system as a whole;
• the spark plug uses less fuel with the same efficiency as its counterparts;
• improved cold start response;
• The BOSCH Duraterm@High Speed ​​glow plug has an extended service life.

BOSCH DuraSpeed ​​glow plugs:

• a ceramic candle with a tubular heater heats up to temperatures above +1300°C in less than 2 seconds;
• operating voltage of the spark plug is 7 Volts or 11 Volts;
• ensuring smooth engine operation even at extremely low temperatures;
• residual heat - up to 15 minutes;
• stabilization of fuel combustion when operating in the urban cycle, this ensures ideal regeneration of the particulate filter;
• reduced fuel consumption during operation;
• can be used in engines equipped with a start-stop system, in particular, it is ideal for use in cars for city driving with frequent engine starts and stops in any weather.

Recently, the BOSCH brand has become less and less popular among domestic car enthusiasts. This is due, first of all, to the fact that the quality of the products is quite low, despite the fact that the declared price does not correspond to it at all. This is due to two reasons. The first is that it has its factories in various countries, including the territory of the Russian Federation. It is these products that are often of poor quality. If, for example, you buy BOSCH glow plugs made in Germany or France, then the quality there will probably be much better. The second reason for the decline in popularity of the mentioned brand is the large number of counterfeits. They are made in China and Russia. However, if you buy original BOSCH glow plugs, they will certainly serve you for many years. Among the disadvantages of these candles, one can note the high price.

Bremi

The Bremi company is located in the city of Kirsp, located in Germany. It produces various elements of automotive ignition systems, including glow plugs. They are original for many models of such world famous automakers as AUDI, BMW and Volkswagen. At the same time, the company produces glow plugs for other European, Asian and American cars. The quality of the company's products is confirmed by certificates TS 16949, VDA 6, Part 1, ISO 9001:2000. Using electronic catalogs, you can similarly select the necessary spark plugs for a wide variety of cars.

Reviews on the Internet for the most part indicate that the original Bremi glow plugs are really quite good. Accordingly, they can be recommended for installation on any suitable equipment. Their price-quality ratio is excellent.

JP Group

The JP Group company is located in Denmark, in the city of Vyborg. The company specializes in the production of various spare parts for European manufacturers such as Volkswagen, Audi, Skoda, Mercedes-Benz, Opel, Seat, Ford, Porsche and others. Many supplied spare parts are original for these machines. The same applies to glow plugs.

JP Group glow plugs are an excellent solution for owners of European cars. They are distinguished by high quality, long service life and excellent performance characteristics. Therefore, they will be an excellent replacement for the original candles or serve as the original ones. Reviews of JP Group glow plugs are mostly positive. The range of produced spark plugs is wide, and allows you to choose a spark plug for a large number of cars.

Brisk

The Czech company BRISK Tábor produces a wide range of spare parts for car ignition systems, including glow plugs under the Brisk brand. Currently, three main types of such candles are produced. The first is spiral. They are used for engines of older designs. These spark plugs are not adjustable. Connected when connecting the circuit in series. There are three models of Brisk spiral candles - 33.50; 34.51; Z25.

However, more modern options are Brisk rod spark plugs for diesel engines. They are divided into two types - with one spiral and with two spirals. A candle with one spiral has a self-regulating function, which makes it possible to regulate the current passing through it, and, accordingly, its operating temperature.

Candles with double spirals, in turn, are divided into two more types - Brisk Exclusive and Brisk Twin. Brisk Exclusive glow plugs have an extended service life of up to 160 thousand kilometers. Their warm-up time to operating temperature is 3 seconds. The spark plug can be used in diesel engines with a prechamber for pump-carburetion engines, including turbocharged ones.

Brisk Twin glow plugs are a simpler option. They can also be used in almost any diesel engines, including turbocharged ones. Candles allow you to meet the requirements prescribed by environmental standards EURO 2 and EURO 3.

The Brisk company has many fans among domestic and foreign car enthusiasts. This was made possible due to the excellent performance characteristics of its products, durability and high quality workmanship. Reviews and tests conducted by car enthusiasts show that the original Brisk glow plugs can indeed be installed on diesel engines, thereby ensuring its normal operation in the long term.

SWAG

The SWAG company produces various spare parts for such world-famous automakers as Mercedes Benz, BMW, Porsche and many others. Including glow plugs. All manufactured products are confirmed by international certificates. However, in addition to producing its own products, the company also packages parts produced under another brand (for example, the mentioned FEBI). And in some cases, it turns out that the car owner overpays, since it will be cheaper to buy the same FEBI.

In general, reviews from car owners about SWAG glow plugs are mostly positive. Therefore, they can be selected from the electronic catalog available on the manufacturer’s official website or in specific online stores. They are especially suitable for European (mainly German) cars.

Checking with a light bulb

This method involves the use of conventional control. It is not always possible and relatively informative, but it also has a right to life.

To check, a 12V light bulb with a power of 21 W will be used, for example, from the stops, two wires. One of the wires can be made shorter, the second should be long enough to reach the battery.

The check can be carried out both on a removed glow plug and on one installed in the engine.

In the first case, the role of mass will be played by the negative terminal of the battery, in the second - by the body of the diesel unit.

• Disconnect the power supply wire from the product;
• We connect one test wire to the positive terminal of the battery, the second to the spark plug terminals.
• If the test is carried out on removed heating elements, then their housings should touch the negative terminal of the battery.

A bright light indicates that there is no break. Absence of light - there is a break. But we still won’t know what condition the product’s rods are in.

The only thing that will indirectly indicate the problem to us is the dim lighting of the lamp. This will make it clear that you need to carry out more thorough diagnostics of the devices, for example, with a tester.

On the issue of fakes

Currently, you can often find fake glow plugs on the shelves of auto stores. They are mainly produced in China and the Russian Federation. Naturally, the quality of such products is much worse than the original ones. And, accordingly, they will not only be used for less time, but will also not meet the declared characteristics. Moreover, they can cause direct harm to the car engine. Therefore, when choosing certain glow plugs, it is necessary to use simple methods to minimize the likelihood of purchasing a counterfeit.

First of all, you need to use the services of trusted stores that have all the permits to conduct trade. It is also desirable that they have official permission from the manufacturers of certain goods to sell their original products, that is, they are their official representatives. You should not make purchases at small kiosks with a dubious reputation.

Many modern auto parts manufacturers use modern methods to protect their products using online verification. So, there are several similar methods. This may involve checking the packaging using the code on it through the manufacturer’s official website. Or scanning the QR code printed on the packaging and obtaining the relevant information on the same website of the candle manufacturer. Manufacturers are getting creative in this niche.

If you are sure that your car's engine originally had an original spark plug that failed, it makes sense to take a photo of it. This will help to visually compare the original and the product offered in the store.

Don't forget to visually check the spark plug. Its body must be of high quality, the metal must be well processed, the body must not have chips, burrs, poor-quality engraving, and so on. Same with packaging. Famous manufacturers spare no expense in producing high-quality packaging, including for their protection. The printing must be of high quality, the pictures must be clear, and there must be no errors in the product description.

Conclusion

Glow plugs are an important part of a diesel engine, and their selection must be approached with all responsibility. First of all, it is necessary to consider their dimensions so that they are suitable for a particular engine. Secondly, their type. It is better, of course, to buy ceramic glow plugs, but they are quite expensive, so it is better to install them on expensive foreign cars. In most cases, metal candles are quite suitable. As for specific brands, it all depends on the price-quality ratio, as well as the availability of certain candles in a particular region of the country, since logistics have a significant impact on availability. If you have had positive or negative experience using certain glow plugs, write about it in the comments.

Characteristic symptoms

You should think about how to check glow plugs in a diesel engine if there are the following characteristic signs:

• The engine can be started with great difficulty.
• At idle speed, the power unit operates unevenly.
• There is a white tint in the exhaust.

If the spark plugs were changed not so long ago, this may indicate a defect on the part of the manufacturer. Otherwise, you can be sure that one of the elements is faulty. In any case, it is necessary to carry out diagnostics by visiting a service station or doing everything yourself.

It is worth considering that problems with spark plugs manifest themselves well in the cold season (autumn or winter), while in summer it is quite difficult to determine the malfunction.

Spark plug life and reasons for failure

According to experts, it is very difficult to speak clearly about the life of glow plugs. They are changed every year or two, depending on the quality of the product itself. If we talk about the service life of spark plugs based on mileage, we can come to the following pattern:

1. Products with a metal spiral become unusable after 50-80 thousand kilometers;
2. Products with a ceramic spiral last twice as long as metal ones - up to 160 thousand kilometers;
3. Some Japanese glow plugs for premium cars can last 240 thousand kilometers.

Let us only note that the breakdown of one spark plug will not have a special effect on the engine. Two working candles guarantee operation in the warm season. However, in all cases, it is advisable to change them as a whole set, since even one non-working part will affect the consistency of diesel fuel, and, accordingly, the operation of the engine.

The glow plug will work long enough if the following conditions are met:

• Fuel injectors are working properly. A clogged injector does not spray fuel, but streams it directly onto the spark plug, causing it to burn out;
• The candle is clean. Combustion products can be deposited on the working part, which is why the part can eventually close on the “minus”, that is, the car body, and fail forever;
• The installation was carried out incorrectly. The candle is a rather delicate detail. Excessive force on the key will simply break it;
• Tightness of engine components. Oil contamination is a common cause of failure of many car parts. For example, oil leaks also burn spark plugs in gasoline/gas engines.

A serviceable part is clean, its tip has no swelling. External damage usually indicates excessive tightening during installation, and a broken tip indicates problems with fuel injection. We advise you to check the spark plugs every year for these changes.

As practice shows, most often failure occurs due to incorrect selection and subsequent overheating. We did not describe this point above simply because the rule applies to all consumers of energy from the vehicle’s on-board electrical network: always choose a spare part that meets the vehicle’s parameters. If the rule is not followed, any candle fails very early.

A brief tour of brands

As already mentioned, original candles are a priority. You will buy exactly what suits your vehicle.

You can save significantly by purchasing candles from Japanese brands Denso and NGK or German Beru. All three options are very good. We are especially pleased with NGK products - this company produces the most advanced parts for ignition systems, and a significant part of them is supplied directly to the factories of large automakers.

One cannot help but pay attention to the American company Champion and the German Bosch. These are clear winners of the “audience choice”, because their products make up the majority of the glow plug market in Russia and Ukraine.

Also, if you decide to save money, pay attention to the Danish company JP Group and the Polish Maxgear - their products are inferior to those of the above brands, but meet all quality standards. The best option for new diesel cars.

Understanding ceramics

Owners of modern diesel cars in many cases can replace worn-out metal glow plugs with ceramic ones. Having overpaid, they receive a whole set of “bonuses”. Namely:

• The ability to start driving almost immediately after starting the engine. Ultra-fast heating contributes to this;
• An almost eternal life of a glow plug, especially if it was produced by one of the companies that we will talk about later;
• The probability of burning out the heating coil is close to zero.

Here we can draw an analogy with iridium spark plugs used in gasoline and gas engines. The price is steep, but there is an opportunity to save for yourself something that is very difficult to translate into monetary equivalent: your own nerves. A high-quality ceramic product is either not replaced at all, or at most only once during the entire life cycle of the car. Of course, if you take care of it properly. Then, most likely, you will not have to check the spark plugs at all for carbon deposits and mechanical damage - set it and forget it.