What happens if your spark plugs are white?

Spark plugs are an essential ignition system component that ensures your vehicle starts. However, they can get fouled due to age or other faulty components. Meanwhile, faulty spark plugs appear in different colors.

Sometimes a fouled spark plug may have black soot on the tip, and other times white, oily, etc. Understanding these colors is easy to spot why your plugs are failing and reveal your engine’s condition. This brings us to ask what does white tip spark plug mean?

What does a white tip spark plug mean?

A white tip spark plug means your spark plugs are burned due to running too hot. However, there is something to keep in mind. If the white deposits are relatively weak, there is nothing to worry about.

It is very common for spark plugs to form white deposits since they operate under high temperatures. Iron oxide and fuel impurities can cause this whitish color when oxygen meets with the plug’s steel body.

However, if thick white deposits are on the spark plug tip, you might have a more severe problem. Now, if these thick white deposits form due to spark plugs running too hot, why do spark plugs get too hot?

What causes white spark plug

Since the white tip spark plug indicates spark plugs running too hot, let’s see why they are running too hot.

Uneven air-fuel mixture

For complete combustion to occur, the combustion chamber needs the air-fuel mixture in a particular proportion. Now, certain components, like the mass airflow sensors, injectors, carburetors, etc., are responsible for ensuring that this air-fuel mixture is in the correct ratio.

When they get faulty, it can result in your engine running on lean air fuel, resulting in the engine not reaching its normal operating level. Ultimately resulting in black plug or white deposits forming on the tip of your spark plugs.

Engine overheating

An overheating engine exposes the spark plugs to operate under temperatures higher than usual. The excess heat invariably forms white deposits on the spark plug tip. An overheating engine may indicate your cooling system is not functioning well.

Low-quality fuel

Poor quality fuel causes your engine to work harder than usual—invariably producing excess heat. White residues will form on its tip with your spark plugs exposed to such heat.

Incorrect ignition timing

The spark plugs are supposed to ignite the air-fuel mixture in the combustion chamber at a particular time. If the ignition timing over stretches, the air-fuel mixture can shoot too early, leading to engine explosion and heat. With your spark plug exposed to such heat, white residues will form on the plug’s tip.

Worn, loose or incorrect spark plugs

When spark plugs are bad or loose, they find it difficult to ignite your air-fuel mixture in the combustion chamber. This ignition delay often causes detonation of the mixture, resulting in engine explosion and heat. In addition, the plugs exposed to such temperature often lead to white tip spark plug.

Again, every vehicle uses specific spark plugs that can withstand engine heat. If you use an incorrect spark plug, it may not be able to withstand your engine’s heat range. Hence the excess heat leads to white residues on the plug’s tip. Or it could be that you fitted your vehicle with spark plugs whose heat range is too high.

Can bad spark plug cause a lean condition?

Spark plugs naturally will not cause a lean condition. They have to create ignition to burn the air-fuel mixture. However, they can trick the oxygen sensor to create a lean condition when they go worn. Here is what happens.

When spark plugs go bad, they fail to ignite the air-fuel mixture, resulting in incomplete combustion.  Unburnt fuel, due to incomplete combustion, invariably gets dumped in your exhaust.

With unburnt fuel in the exhaust, the oxygen sensors may think that the combustion chamber is getting too much fuel from the fuel injectors.  When it relates this information to the ECU, the ECU reduces the amount of fuel entering the combustion chamber and pumps more air instead.

What color should the tip of a spark plug be?

The tip should be grayish tan or brown for a normal spark plug that has been running for several thousand miles. However, when something goes wrong, this color may change. Generally, what color it changes depends on what component is causing it. This is why it is essential to understand the spark plug color chart, as it would tell you which component needs fixing.

For example, dry black soot on the electrodes and insulator tip indicates that your plugs are fouled by carbon deposit. Often resulting from regularly driving at low speeds, dirty air filters, long idle, or running rich air-fuel mixture.

A black oily deposit on the spark plug tip may mean oil leaks into the cylinder and gets past worn pistons and valve guides. Therefore, a practical way to identify potential engine problems is to understand your spark plugs by studying the spark plug chart.

https://youtu.be/QEn3x0y5G2oVideo can’t be loaded because JavaScript is disabled: Spark Plug Deposit Diagnosis (https://youtu.be/QEn3x0y5G2o)

How to fix white spark plug tip

Generally, a spark plug tip gets whitened when it is running extremely hot. So to fix a white spark plug tip, you first need to know which component makes your spark plugs hot.

While we’ve stated why plugs run hot, a proper analysis or inspection will point you to the real culprit.  You can fix a spark plug white tip by doing the following.

• Change faulty injectors and carburetors. If the carburetors are not correctly adjusted, adjust them.
• Drain out bad fuel and fill your gas tank with a premium fuel tank with the correct octane level.
• Change worn-out spark plugs.
• Use the correct spark plugs recommended by your vehicle manufacturer.
• Ensure all components of your cooling system are working well.
• Replace with a cold range spark plug if your spark plug heat range is too high.
• Lastly, clean the white residues from the spark plug after fixing whatever is causing it. However, cleaning is only possible if the white residues are few.  If  you have a thick build-up, you would need to replace the plugs.

Cleaning white residues from spark plugs

Tools needed

• Sandpaper
• Socket wrench or screwdriver head
• Cleaning agent (solvent)

Method 1

Locate the spark plugs. Then remove the high voltage wiring or the individual coils screwed into place with a screwdriver head or socket wrench (depending on your model). Next, fold a sandpaper in half and remove the white residue between the electrodes carefully. This method is not recommended for iridium plugs.

Method 2

Use the solvent to clean the spark plugs and the electrodes. Alternatively, you can put the plugs in a bowl, add the cleaning agent and let it sit there for a while. Afterward, rinse with a solvent to remove the remaining residues. If some residues are still left, clean with a towel. Return them to your car when they are dried.

Conclusion

For those wondering what does a white tip spark plug mean? It means your spark plugs are burnt due to running hot. This could be due to faulty injectors/carburetors causing a lean fuel. A bad or incorrect spark plug and low-quality fuel could also run out your plugs.

The only way to fix a white tip spark plug is to repair those components responsible for it. Failure to fix these components will cause your engine to suffer damage since these components also work with other components.