Signs of problems with spark plugs

In case of problems with starting the engine, most drivers declare the battery the sole and main culprit. The problem may indeed be the battery, but this is not the only option for a difficult or impossible start.

Observations show that in a rather large percentage of cases, the problem is worn out or untimely replaced spark plugs.

Symptoms Indicating a Problem with Spark Plugs

Not always a problem starting the engine or its unstable operation is associated with spark plugs. Here are a few signs that may indicate this.

The engine has a rough idle

When the engine is idling, crankshaft usually rotates at a speed of about 1000 rpm, and the sound that the motor makes is smooth and pleasant to hear. However, if the spark plugs do not work properly, the sound becomes harsh and the vibrations in the car are amplified.

Launch problem

As mentioned at the beginning, in case of problems with starting, the battery may run out or the fuel system may be malfunctioning. But there is also the possibility that the spark plugs need to be replaced. When they are damaged or worn out, they cannot produce the spark necessary to smoothly start the engine.

Increased fuel consumption

If you notice that fuel consumption has increased, pay attention to the condition of the spark plugs. Fuel consumption can increase up to 30% and only because they do not function properly and cannot provide high-quality ignition of the air-fuel mixture.

Weak dynamics

If the car is accelerating slowly or does not want to accelerate, it may also be a sign that it is time to take a look at the condition of the spark plugs.

Why do spark plugs fail?

These elements of the car ignition system operate under increased thermal and electrical loads. They are also affected by high pressure and the chemical effects of fuel.

The spark they create reaches 18 to 20 thousand volts, which leads to overheating and burnout of their components. Adding to the driving style and operating conditions of the car, it becomes clear that spark plugs can wear out over time.

When should spark plugs be replaced?

Despite their great variety, spark plugs are conventionally divided into ordinary and durable. Manufacturers indicate recommended spark plug replacement intervals in the vehicle manual.

Usually, when it comes to conventional spark plugs, it is recommended to replace them every 30 to 000 kilometers. For spark plugs with extended life (platinum, iridium, etc.), it is recommended to change every 50-000 kilometers, depending on the type of car and engine.

Of course, it may always be necessary to replace the spark plugs much earlier than expected if a problem is detected with them.

How to change spark plugs?

Spark plugs can be replaced both in the workshop and on their own. It depends only on the knowledge and skills that the car owner possesses. If you are confident in your technical knowledge and possess the necessary skills, you can easily replace the spark plugs by following these steps.

Savant Providence

Read the car manual and buy spark plugs recommended by the manufacturer. If you cannot find the information you need, contact a well-known mechanic or an employee of the auto parts store.

The tool you will need is a spark plug wrench, torque wrench, clean rag or cleaning brush.
Spark plugs are replaced as follows

Find out where the candles are

When you raise the hood of the car, you will see 4 or 8 wires (cables) that lead to different points of the engine. Follow the wires that will lead you to the spark plugs.

If the engine is 4-cylinder, the spark plugs are likely to be located on top or side of the engine. If it is a 6-cylinder, then their location may be different.

Engine disconnected from battery

Whenever you are working with a car, you must make sure that you disconnect the battery cable and the car engine is turned off and completely cooled.

Remove the first high-voltage wire from the candle

You can remove all the wires at once, but you need to number them and remember which one is connected to where. This is necessary so as not to confuse the sequence when installing new spark plugs.

It’s much easier to take them off one at a time. Remove the first cable by carefully pulling on the candlestick (the cap that is put on the candle). Take the candle key and use it to unscrew the candle.

Clean the edge of the candle well

Before installing a new spark plug, clean the area around the spark plug with a clean cloth.

Check the clearance and adjust if necessary

Modern spark plugs are supplied by the manufacturer with the appropriate clearance, but it is still worth checking to be calm. If the gap between the electrodes is too large or too small, correct it.

You can take measurements with a special probe. Correction is performed by slightly bending the electrode and slowly adjusting the distance.

Install a new spark plug

To install a new spark plug, take the spark plug again, insert the spark plug into the socket and tighten it well. Do not tighten the candle in the well too much.

It should be simply wrapped well, but so that the thread does not break. For a more correct installation, you can use a torque wrench.

Install the cable

The high voltage wire is easy to install. just put the candlestick on the candle and press it all the way (you should hear a distinct click or two, depending on the design of the candle).

Repeat steps with other spark plugs.

If you manage to replace the first candle, you can cope with the rest. You just have to follow the same sequence.

We start the engine

After replacing all spark plugs, start the engine to make sure that the spark plugs are installed correctly and are working properly.

If you are not sure you can handle it, or if your spark plugs are in a hard to reach place, you can contact a service center. Replacing spark plugs in the workshop is not too expensive and saves you time and nerves.

It is good to know that the final replacement cost depends on both the type of spark plugs and the design of the engine. For example, if your car has a standard 4-cylinder engine, replacing spark plugs is a relatively simple task. However, if he has a V6 engine, in order to get to the spark plugs, the intake manifold must first be removed, which increases the operating time and, accordingly, the material costs of replacing the spark plugs.

The most common candle replacement questions

Do all spark plugs need to be replaced together?

Yes, it is ideal to replace all the spark plugs at the same time. This is the only way you can be sure that all spark plugs are in good working order.

Do I need to replace the wires with the spark plugs?

This is not necessary, but some experts recommend replacing the cable with the spark plugs. Over time, high-voltage wires crack, become brittle, so they should be replaced.

Can spark plugs be cleaned?

Old models of spark plugs can be cleaned. New candles have an extended service life and are replaced with new ones after the end of this period.

Is it good to replace spark plugs ahead of time?

It depends on the mileage, method and driving conditions. If during a regular check everything looks good, and if you do not notice any of the symptoms listed above, there is no need to change the spark plugs earlier than provided by the manufacturer.

Questions and answers:

How to understand that candles have become unusable? The motor began to start with difficulty. Often floods candles (not only the problem is in the candles), the engine troit, the dynamics of the car has decreased, From the exhaust smell of unburned gasoline. When you press the gas, the revolutions fail.

How do spark plugs affect engine starting? Defective spark plugs create a weak spark or no discharge at all between the electrodes. If the spark is thin, its temperature is not enough to ignite the HTS, so the motor works much worse.

How do you know when it's time to change the glow plugs? Measure the voltage at the contacts of the spark plug (voltage drop even by one volt is the reason for replacing the spark plug). The schedule for the planned replacement of candles is about 60 thousand.