White spark plugs? White soot on candles: causes and solutions to the problem

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

The working part of the spark plugs is located directly in the combustion zone of the fuel mixture. Often, a part can serve as an indicator of the processes that take place inside the cylinders. By how much soot settles on the electrode, you can determine what is wrong with the engine. Black soot means a rich fuel mixture. Almost all drivers know this. But white spark plugs cause a lot of questions from motorists. Let's look at the main causes of white soot and how to solve such a problem.

What color of soot can be considered normal?

The electrode with a light brown coating indicates that the engine is running normally. At the same time, there should be no soot or oil deposits on the electrode. This picture can be observed in new engines, as well as engines after overhaul.

If the working part of the candle hasa different color, then it is better to perform engine diagnostics and find the cause of the malfunctions. At the same time, the problem does not always lie in the motor itself. As for the colors of soot, it can be black, brick or frankly red, light gray. There are also white spark plugs.

Main cause of raid

The first thing to consider is that the spark plug is needed to ignite the mixture of fuel and air. The candle inside the cylinder operates under extreme loads in difficult conditions, where various chemical and biological effects are provided - this is the high temperature of the spark and the processes during the combustion of the mixture.

The main reason for the formation of soot is precisely the chemical reaction resulting from the combustion of the fuel mixture. The reaction leads to such consequences as high temperatures and the formation of decomposition products. After each burning of the next portion of the fuel mixture, a small amount of plaque settles on the spark plug electrodes and cylinder walls.

Causes of white soot

If there is a white coating on the spark plugs, experienced motorists will immediately determine the problem. This is a lean fuel mixture - relevant for both injection and carburetor engines. But there are other reasons as well. This is late ignition, as well as incorrectly selected candles for a particular engine. To find the exact cause of such a malfunction, it is necessary to carry out a phased diagnosis of the car.

Poor mix

Mixturefuel and air must be correct - only then the engine will work perfectly. But this is not always the case. Even modern fuel injection systems, which are completely controlled by electronics, sometimes fail.

If there is white coating on the spark plugs, then there is more air in the fuel mixture than needed. You need to find the cause of the lean mixture. Often, such a malfunction is associated with the suction of foreign air into the system, as well as with the poor performance of the fuel pump. In addition, the engine can lean the mixture due to various malfunctions with the air mass meter and other sensors.

In the case of a carburetor, the fuel jets of the main metering system or the idle system may be clogged. Often a lean mixture provokes too low a level of gasoline in the float chamber. Often a malfunction is associated with a clogged fuel filter or fuel intake in the tank. That's why the spark plugs are white on the carburettor - in most cases it's lean.

To normalize the situation, you need to find and fix the problem, then drive for a while on a set of candles, and after a while unscrew them and look at the condition.

Incorrect fuel mixture adjustment

This is one of the causes of a lean mixture. Often even on injection engines there is the possibility of adjustment. For example, in order to save fuel, drivers change the throttle opening angle by changing the position of the retaining rings, shifting it in the grooves of the needledampers. But such mythical savings can lead to disastrous consequences. Riding on a lean mixture, as indicated by white soot on candles, can cause valve burnout.

You can make changes to the firmware of the control unit. There are many software and hardware tools available for this. Fuel mixture adjustments are made to increase engine power.

Injectors and fuel filters

This is a commonplace cause of white spark plugs on injection engines. The needle and nozzle of this element are very thin, however, due to the poor quality of the fuel or a clogged filter, various deposits form on the nozzle walls over time. The diameter of the passage hole, which is already very small, is further reduced. All this provokes a lean mixture.

In this case, the best and most effective solution is the regular replacement of fuel filters - both fine and coarse. Cleaning and purging nozzles on special stands can also help.

Air suction

A lean mixture can also form due to outside air being sucked in. If it is not possible to find the cause of the white spark plugs, and all checks have shown that the components and elements are in good condition, then it is recommended that you carefully examine each hose and pipe that goes from the air filter to the intake manifold. It is necessary not to forget that depressurization of the intake manifold itself is possible. Cracks can often form in an aluminum part. Replacement will be expensive, but will help get rid of white soot oncandlelight and lean.

In addition, air leakage may be where the idle speed sensor is installed. Experts recommend carefully checking the rubber seals that seal the joint.

Later ignition

The mixture of fuel and air that an internal combustion engine runs on can ignite later than necessary. In this case, it burns out during the stroke of the piston. This simultaneously causes burning of candles and overheating of the motor. Late ignition can cause white coating on spark plugs.

On old simple carburetor engines, you can adjust the lead angle with your own hands using a stroboscope. But on engines with high mileage, this is difficult to do. In this case, the ignition should be set empirically, since the stroboscope does not take into account the wear of individual engine elements.

In do-it-yourself injection engines, the UOZ cannot be changed in any way - it is rigidly set in the firmware of the control unit. Here it is necessary to check the sensors responsible for the ignition moment one by one and change those that are faulty.

Wrong matched candles

Spark plugs are divided into "hot" and "cold". For each engine, manufacturers recommend their own kits. Often, products that are on the shelves of car dealerships may not meet the declared characteristics, and motorists buy and screw in such spark plugs.

White deposits indicate that the part is too "hot" toof this motor. To fix this problem, you just need to purchase and install the correct candles. It is possible to identify that the part does not match the glow number, not only by soot, but also by the characteristic traces of overheating or melting of the ground electrode.

Unfortunately, now there are no generally accepted standards for marking the glow number. Therefore, the most suitable candles for engines of a particular model should be selected only from catalogs.

But white coating on spark plugs HBO is considered normal. But still, it is better to purchase special gas parts, check the quality of the mixture and make sure that the proportions are normal.

How to maintain?

It is customary to change spark plugs that have traveled 30-40 thousand kilometers. But few people know that candles need to be serviced. Even with a fully functional ignition system, they may not work correctly. Various deposits and oxides can form on the electrodes, which interfere with the formation of a normal spark. In the process of metal burning out, the gap between the electrodes grows, which also complicates the process of sparking.

To prolong the life of the candles, they can be cleaned. But if you only clean the white spark plugs, the effect may not be due to the increased gap between the working parts. It is necessary to restore the normal clearance. Then the ignition system will work perfectly.

Other colors

We learned what white soot on spark plugs means. But there are also other shades that are alsocan tell a lot.

For example, black candles. Black soot can have a different structure. And it's one thing if it's just dry soot in the form of soot. The main reason is an over-enriched mixture. An oily coating indicates that a lot of oil gets into the cylinders and it does not burn out completely. Also black plugs will be on engines that have big oil appetites.

You can also observe red soot. But he doesn't talk about any problems. But it only indicates that there are certain additives in the fuel that the car is filled with. Experienced motorists and repair specialists cannot name other reasons for the appearance of a red coating.

Conclusion

So, we have examined why there is a white coating on candles. As you can see, there may be several reasons for this problem.