Brown deposits on the spark plug insulator

There are many ways to diagnose the condition of a car engine. Among the most frequently used are computer diagnostics, compression measurement and others, but most of them require special equipment. However, there is a sign by which you can quite accurately determine how well the engine is working, without the use of additional tools - this is carbon deposits on the spark plugs. The appearance of a turned-out spark plug can tell a lot about the condition of the power unit and the correct operation of the auxiliary systems.

Why does a brown rim form on the spark plug insulator?

Most experts tend to agree: the plaque is caused by low-quality fuel, which is not distinguished by the purity of impurities and the absence of deposits. Such problems in gasoline cannot be determined with the naked eye or by smell, but by looking at the spark plug insulator after some time of operation, everything will become obvious. The brown spots themselves may differ in shade and structure; only after a qualitative examination of the part will it be possible to identify the exact causes of the suspicious excess.

Erosion

Erosion can also occur in a properly functioning mechanism. Parts often show slight signs of erosion.

In such cases, it is recommended to replace the damaged part or fuel.

Erosion occurs when the side electrode on the spark plug is bent excessively. With prolonged use, erosion causes failures. The engine may not start right away, malfunction after warming up, or stall.

Causes of carbon deposits on the spark plug insulator

The brown rim is divided into several colors, as well as the structure of the contamination. Based on this, you can accurately determine the faulty part of the car. A velvety dark shade indicates the penetration of the fuel mixture into the combustion chamber due to a clogged air filter.

Brown deposits on candles

A redder color means that the piston system caps or rings require replacement, in which case the oily liquid penetrates the combustion chamber, leaving a rim on the insulator over time. It is possible that the caps are unsuitable for connecting the mass to the igniters; these components must be periodically replaced.

Spark Plug Maintenance

If you have driven more than 30-40,000 kilometers on the same spark plugs, then even with a working ignition system, they will begin to act up. Plaque and iron oxide form on the electrodes, preventing the formation of a spark. In addition, when the metal burns out, it increases the distance between the electrodes, which complicates sparking.

Typically, spark plugs are replaced after long-term use, but in some cases their service life can be extended. To do this, just clean the contacts. But if you just clean the carbon deposits, the effect may be negative due to an increase in the gap between the electrodes.

You can restore the nominal gap by bending the upper electrode of the spark plug, monitoring it using a special probe.

Gap gauge

You should also pay attention to the condition of the insulators. If the insulator has cracks or other mechanical damage, the spark plug must be replaced. The presence of oil and dirt on the insulator is unacceptable. This reduces the effectiveness of the insulator, reducing resistance to electrical current. Its surface must be cleaned.

If the surface of the insulator is covered with an oil coating, then it is possible that the spark plugs are not screwed in tightly. They need to be unscrewed, the seats, contacts, insulators must be cleaned and screwed in again using a torque wrench. Table 1 shows torque values depending on the type of spark plugs and head material.

Flat Fit Spark Plug (with Seal)				Tapered Fit Spark Plug
Cylinder head material	Thread diameter				Thread diameter
Cylinder head material	18 mm	14 mm	12 mm	10 mm	18 mm	14 mm
Cast iron head	35-45 Nm	25-35 Nm	15-25 Nm	10-15 Nm	20-30 Nm	15-25 Nm
Aluminum head	35-40 Nm	25-30 Nm	15-20 Nm	10-12 Nm	20-30 Nm	10-20 Nm

What does the formation of yellow carbon deposits on the spark plug insulator indicate?

Having seen spots of such a characteristic shade, drivers often encounter problems when starting the engine. The reason is the same low-quality fuel, only there is an increased presence of lead in the mixture due to the unscrupulous attitude of the gasoline supplier to the creation of its products. If you refuel with such fuel for a short time, then irreversible changes in the operation of the vehicle can be avoided; it’s another matter when the driver ignores the manifestation. In addition to problems with spark plugs, the car owner will face serious disruptions in the functioning of the entire power plant.

Red soot

If the fuel poured into the gas tank contains an excessive amount of additives, a red coating with a brick tint may appear on the device. Often the appearance of a red tint is caused by the fact that the additives contain metal. If such fuel is used regularly, then a deposit that conducts current occurs, which leads to interruptions in operation.

When a red tint appears, experts recommend changing gasoline.

Other types of damage and contamination

Mechanical damage to the electrode skirt can have several causes:

Problems with the gas recirculation valve
Inaccurate lead angle
Unsuitable fuel type
Excessive cooling
Part failure

Sometimes the body has a reddish tint, but this may not be carbon deposits on the candles. Most often, the tint is caused by the fact that water gets on the engine and the part is simply covered with rust.

Rust may appear after washing, during bad weather, if the hood is insufficiently waterproofed. Experts most often recommend replacing the damaged part.

Frequency of replacement of spark plugs and main causes of plaque

Spark plugs vary in type and destination; in the automotive industry, spark plugs are widely used, the lifespan of which is determined by the type of engine, the type of fuel for the engine and the recommendations of the manufacturer of both the car and the spark plugs. Spark plugs for engines running on reduced natural gas last no more than 10,000 km, while spark plugs for diesel engines should be replaced after 12,000 km, and for gasoline power units after 15-16,000 km, that is, every maintenance.

If problems arise with the engine, the first thing to do is to diagnose the spark plugs, because In 85% of cases, they are the most common cause of vibrations when driving and when the car slightly pulls to the side. You can diagnose the spark plugs yourself using the instructions for replacing spark plugs. By pulling out one of the spark plugs, you can determine by the plaque the type of problem existing in the car system, which is why the spark plug is unable to work properly. The following types of layering on candles are distinguished by color:

The color of soot is the color of the burnt impurity contained in the fuel. Ideally, natural impurities in good fuel are practically not deposited on the spark plugs, except perhaps in the form of light salt deposits, giving a slightly grayish color. It is worth noting that problems in the engine are determined not only by color, but also by the structure and density of carbon deposits (plaque).

The reasons for the layering may be a universal cloud, but of the variety of choices, the most common are:

Poor quality fuel;
Fuel filter malfunction;
Marriage candles;
The spark plug does not match the engine.

How to fix the problem

Now you need to understand what to do if the spark plugs are filled with gasoline or other technical liquid.

In a situation where the spark plugs are flooded, it is unlikely that you will be able to start the engine easily. If the first few attempts are unsuccessful, further launches will only make the situation worse. Therefore, first you need to eliminate the provoking factor, and then try again.

We will tell you in more detail about how to start a car if the spark plugs are flooded heavily and the ignition system does not want to work. Again, it all depends on the specific liquid.

Petrol

It is recommended to find out why the engine is actively flooding the spark plugs when starting the internal combustion engine. To begin with, motorists are advised to blow out the cylinders for 10 seconds using an open throttle. This will create the leanest possible mixture.

Next, the spark plugs are unscrewed, cleaned, dried, and the gap is checked for correctness and damage to the body or electrode. If you have a multimeter, measure the voltage on the battery. It is possible that the battery simply died.

What you definitely don’t need to do is continue to unsuccessfully try to start the engine. Otherwise, there will be even more fuel on the spark plugs.

If you don’t know how to dry the engine cylinders and start it when the spark plugs are flooded, use these instructions:

If the motor is silent after the 3rd attempt, let it rest for about 10 minutes. Then the operation can be repeated.
Charge the battery. This is done with a charger or using another machine using the lighting method.
Unscrew the spark plugs and insert new ones in their place. If there are no new ones, the old ones will need to be wiped and dried.
Try starting again when the spark plugs are dry and the battery is charged.

There are other recommendations that may help.

We are talking about such manipulations:

If your battery is charged, press the gas pedal to the floor and try to start the internal combustion engine. If you have a manual transmission, depress the clutch as well. Relevant if the engine is fuel injected.
When the engine is carburetor, similar actions are performed. The effect varies, but it can help.
When mixing fuel with water, you can completely drain the bad fuel and dry the tank, the system, or add a drying additive.

It is possible to solve the problem, but you must act carefully and consistently.

Oil

If the engine is cold or hot, and it is filled with oil, then the following actions may be required:

if the oil in the crankcase is more than normal, drain to the required level;
remove oil using napkins, rags or a syringe;
burn out the remaining oil, clean the candle if you plan to reuse it;
replace seals, guides, piston rings;
clean the ventilation system;
replace the intake manifold gasket.

Guides can sometimes be repaired or replaced. Oil seals are also replaced when there is severe wear, but always together with worn bushings.

Here everything depends on what kind of malfunction we are talking about. Having diagnosed why exactly when starting the engine the spark plugs are actively filled with engine oil, the cause is first eliminated, after which new or restored spark plugs are installed.

Antifreeze

Typically, coolant getting into the oil and its further penetration onto the spark plugs is associated with burnout of the block gasket, or with a change in the geometry of the block head. This problem is solved by replacing the gasket and grinding the surface. No other way.

If the geometry of the cylinder head is violated, you will have to contact the service. Machines are used there and the shape is restored. It will not be possible to restore the heat exchanger or gasket. Replacement only.

It is extremely rare for motorists to encounter changes in the geometry of the block itself. Again, without the help of specialists and equipment, the problem cannot be solved on your own. And even they are not omnipotent, which is why it is often necessary to completely change the engine.

Flooded spark plugs are not uncommon among motorists. Basically, the filling occurs with fuel. In case of more serious malfunctions, the spark plugs may contain motor oil or antifreeze.

How to clean spark plugs from carbon deposits

Since stable engine operation depends on the condition and performance of the spark plugs, these elements require care and require timely replacement. As mentioned above, during operation of the power unit, the spark plugs become covered with soot, deposits affect the quality of spark formation and impair the performance of the ignition system.

Taking into account the fact that the service life of spark plugs is limited for a number of natural reasons and strongly depends on the quality of the product, additional accumulation of carbon deposits leads to premature failure of these elements, melting of the electrode occurs, and other defects appear. This can be avoided by cleaning the spark plug from carbon deposits. This cleaning allows you to drive 5-15 thousand km longer with one set.

In order to clean spark plugs with your own hands at home or in the garage, you can use several available methods of mechanical and chemical cleaning.

The easiest method for cleaning spark plugs is to remove carbon deposits using a wire brush and fine sandpaper. The advantage is simplicity and efficiency. In fact, the car owner manually removes the main contaminants with a brush, after which additional sanding is done with sandpaper. However, this method also has its drawbacks. First of all, after such cleaning, the spark plug insulator becomes covered with scratches, after which carbon deposits are deposited even faster. Also, excessive efforts during cleaning can lead to a violation of the gap between the electrodes, increasing the risk of electrode failure. For this reason, it is not recommended to use metal objects (screwdriver, awl, knife, etc.) to clean electrodes.
Another method of mechanical cleaning is to remove carbon deposits using sandblasting. This solution is actively used at car service stations. Carbon deposits and deposits are removed using blown sand, after which additional blowing is carried out with compressed air from the compressor. This service has a low cost and allows you to thoroughly clean the spark plugs with minimal damage and scratches, and also saves the car owner’s time.
In garage conditions, you can clamp the spark plug in the chuck of a reverse electric drill, after which, at speed, the spark plug is lowered into a container with sifted sand. This approach allows you to quickly clean the elements from heavy contamination. In some cases, spark plugs are also cleaned ultrasonically. The principle is similar to cleaning an injector in an ultrasonic bath; it combines the effects of ultrasonic waves and active chemistry. In this case, it should be taken into account that the specific nature of the contamination on the candles does not allow the most effective removal of carbon deposits and deposits using the specified method.
With that said, many drivers prefer chemical cleaning to the method of physically removing carbon and deposits from spark plugs. In order to clean candles yourself, household chemicals are suitable. Some also use vinegar, heat candles in phosphoric acid or Coca-Cola, use silite, etc. Note that affordable products for removing rust and limescale have proven themselves to be the best. Such compositions are used for cleaning kitchen stoves, tiles, sinks, etc. Let's dwell on this decision. To remove dirt, you need to prepare a rag, a brush or a toothbrush, some water and a container convenient for use (a flat bowl, a shallow pan).

To clean spark plugs with detergent, follow these steps:

The cleaner is poured into a pre-prepared container. You need to pour in such an amount that the candle is completely immersed in the cleaning composition;
then the elements are soaked in the cleaner for about 30 minutes;
after removal, remove any remaining deposits and carbon deposits with a brush or toothbrush;
the final stage is rinsing in plain water, after which the candles are wiped with a rag as efficiently as possible;

Let us add that an important condition before installing it back into the engine is to dry the spark plugs. This can be done with a household hairdryer or place candles in the oven at a minimum heating temperature for 10-20 minutes, etc. It is not recommended to ignite spark plugs on gas or dry them with a hair dryer. The fact is that significant heating can lead to failure of the spark plug, cracking of the insulator and other defects.

The advantages of this cleaning method include simplicity, absence of mechanical damage, and the effectiveness of cleaning carbon deposits using household chemicals. Deposits are well cleaned from all elements of the spark plug and washed out of hard-to-reach areas. It turns out that such cleaning allows you to remove carbon deposits not only from the electrode, but also to remove deposits from the threaded part and insulator.

A worthy alternative is cleaning candles in a solution of ammonium acetate. For implementation, you will need water, a solution of ammonium acetate in water 20%, gasoline or carburetor cleaning fluid, and a brush with stiff bristles. You should also take into account that the candles will need to be heated in the solution, that is, you need a gas or electric stove.

The sedum itself involves the following actions:

first, the spark plugs are washed in gasoline or cleaner, which allows them to be degreased;
Then the elements are dried superficially. After this, the aqueous ammonium acetate solution is heated on the stove to 100 degrees Celsius or so;

Please note that you should not heat such a solution or work with ammonium acetate in closed, unventilated areas, as the vapors can be harmful to the body if inhaled. Before you start cleaning, you need to take special care of ventilation (open the windows, turn on the hood, etc.).

then the spark plugs should be immersed in the hot solution for 30 minutes. During this time, the temperature of the solution should be maintained; slight boiling is allowed;
upon completion, the spark plugs are removed, then they are cleaned using a brush;
after this, the cleaned elements are rinsed in water and dried thoroughly;

Possible reasons for the appearance of soot

Before answering the question of why the candles are black, you need to decide how exactly they turned black . After all, it depends on which direction to search. In particular, the candles can turn black all together, or maybe only one or two of the set. Also, the candle may turn black only on one side, or perhaps along its entire diameter. There are also so-called “wet” and “dry” carbon deposits.

It should be noted that the speed of appearance and nature of carbon deposits directly depends on existing faults (if any):

Carbon deposits on new spark plugs begin to form after at least 200-300 km. Moreover, it is advisable to drive along the highway at approximately the same speed and engine load. This way the spark plugs will work in optimal mode, and it will be possible to more objectively assess the condition of the car’s components.
The amount and type of soot depends on the quality of the fuel used. Therefore, try to refuel at trusted gas stations, and not drive with gasoline or similar mixtures. Otherwise, it will be difficult to establish the real cause of the appearance of soot (if it occurs).
In a carburetor engine, the idle speed must be set correctly.

White carbon deposits on the ignition system elements

The gradation of electrode colors from light gray to white (light yellow is also possible) is evidence that the engine is running on a lean mixture. Related reasons may be:

The product is too hot. The heat rating of the product is lower than that recommended by the manufacturer.
Large ignition timing angle.
Using low octane gasoline.

There is no point in delaying in finding out the circumstances that caused this soot-colored condition on the new spark plug.
A lean mixture directly causes overheating of both the igniter and the combustion chamber. Ultimately, this situation can lead to burnout of the exhaust valves. When analyzing the factors that caused a poor quality mixture, it is useful to check for the presence of abnormal glow ignition. A symptom indicating its presence is the reluctance of the engine to stall when the ignition is turned off. In total, this means that the “match” was not created for this engine. This conclusion will not be spontaneous if the heat removal from the igniter is not impaired due to loose tightening of the threaded connection, and there is no dirt under the sealing gasket. If this is the case, then you will have to buy a new kit, after consulting the instruction manual.