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​How Many Glow Plugs Does a Diesel Engine Have?

Feb 7th 2022

glow plugs for a diesel engine

If you’re going to drive a diesel engine, you’re going to need glow plugs. These simple, yet surprisingly smart, devices help your engine create the right circumstances for generating power. But many drives don’t have the faintest clue in terms of how they work or even how many glow plugs their engine has. Learn more about these devices and how they keep your engine running as efficiently as possible.

What Are Glow Plugs?

Glow plugs heat various parts of the engine to make sure it can start, especially in cold temperatures. Diesel engines require large amounts of heat to run continuously. The temperature of the gases inside the combustion chamber is typically around 2,800° F. If the engine fails to reach the proper temperature, it will lose power suddenly or fail to start all together.

Glow plugs aren’t the same as spark plugs, which are only found in gas-powered vehicles. Spark plugs create a spark to start the combustion process, but they don’t produce enough heat required for diesel engines.

How Do Glow Plugs Work?

Glow plugs are connected to the combustion chamber where the engine turns compressed air and fuel into power. The glow plugs heat incoming air and fuel as well the cylinders and cylinder block. They are usually made of ceramic or high-quality steel. This technology has come a long way over the last few years. Glow plugs have to walk a fine line when setting the temperature of the air fuel mixture. If the engine is too cold, it won’t start, but if the engine gets too hot, the excess heat could damage vital parts and components. That’s why many glow plugs come with integrated sensors and electronic control systems that regulate the temperature of the mixture based on operating conditions. This prevents the engine from over or under-heating.

auto mechanic in a blue uniform

Shop for Replacement Glow Plugs for Your Diesel Engine Online

Do All Diesel Engines Have Glow Plugs?

Yes, all diesel engines have glow plugs. There is one glow plug per cylinder. Your vehicle will contain either four or six glow plugs depending on how many cylinders are in your engine. Most diesel engines have either four or six cylinders. However, General Motors recently came out with a three-cylinder diesel engine with reduced carbon emissions. Having more cylinders can increase power and performance on the road, however six-cylinder diesel engines tend to cost more and use more fuel than four-cylinder engines. You will also need to spend more time maintaining and replacing your glow plugs on a six-cylinder engine.

Do Cummins Engines Have Glow Plugs?

Yes, even Cummins engines have glow plugs. All Cummins engines have six cylinders to better balance fuel pressure and engine performance. This means that all Cummins engines have six glow plugs.

car glow plugs cause malfunction

Using the Glow Plugs in Your Engine

You can’t drive without your glow plugs, so be sure to treat them with care. The plugs heat air and fuel, so keep your engine as clean as possible to prevent wear and tear.

Your glow plugs will need to go into overdrive during the winter. Do your best to protect your vehicle and fuel from the cold to make things easier for your glow plugs. If your glow plugs aren’t working, the engine likely won’t start at all in freezing temperatures.

Follow the manufacturer’s recommendations when it comes to replacing and repairing your parts. Have your vehicle serviced by a professional at regular intervals to avoid damaging the glow plugs or your engine. This includes replacing diesel particulate filters to improve the quality of your fuel, using fuel additives during the winter, replacing the air filter to remove debris, and having your oil changed on a regular basis.

Watch out for warning signs that your glow plugs need to be replaced, such as hard starting, rough starting, reduced fuel efficiency and sudden loss of power. If you continue driving with faulty glow plugs, you risk further damaging your engine. Consider upgrading to smart or electronic glow plugs to improve engine performance.