Diesel Truck Maintenance: What You Should Know About Glow Plugs

Sales in diesel vehicles are increasing all the time as an alternative to the traditional gas engine. Once reputed to be loud and odorous, diesel engines no longer are. With new technology and standards, and the help of innovative glow plugs, diesel trucks are quiet and maintain high environmental standards.

There are a few important differences between traditional gas engines and diesel engines that make drivers choose diesel. Drivers of diesel vehicles have made this choice because they know that their truck has more torque and towing power than gas trucks. They also know that they have better fuel mileage.

Many diesel owners don’t know what glow plugs are, however. Read on to find out more about how they work and your options. You’ll be glad you did.

What Are Glow Plugs?

In a gas engine, the spark plugs start the engine by emitting a spark that ignites a gas and air mixture generating power for the motor. A glow plug has the function of heating the fuel under pressure to allow it to self-combust. No spark is required for this function.

Glow plugs are like small heaters inside the hood of diesel engines. Every make and model of diesel engine requires a different number of glow plugs. This is because there has to be one glow plug per cylinder and there are different numbers of cylinders in each engine. 

How Do Glow Plugs Work?

A glow plug is similar to a heating coil inserted in a tube. It looks a lot like a spark plug with a pencil-like shape. It is usually is made from a high heat-resistant metal, like platinum or iridium. It has a heating element on its end with a temperature sensor.

The glow plugs have screw-in threads and a single-pole connecting pin glued to the housing using a non-releasable aluminum nut.

If you’re looking for your glow plugs, you can usually find them in the pre-combustion chamber of your diesel engine or the combustion chamber.

Glow plugs function with heat and pressure. Diesel engines require heat to start, especially in low-temperature weather conditions. The glow plugs supply this need as follows:

1. Pre-heating

The heating coil inside the glow plug quickly generates heat for the fuel. Depending on the glow plug, the temperature of the unit can reach over 1000°C within seconds.

2. Compression

The air intake valve in the cylinder closes. The piston rises, compressing the air to 6% of its former volume. 

3. Ignition

The piston reaches its highest point. The fuel heated by the glow plug is injected into the combustion chamber, combines with the compressed air, evaporates, and ignites.

4. Temperature Maintaining

The glow plugs keep the heat maintained for at least 3-5 minutes to ensure combustion continues. This also helps reduce the number of emissions and the build-up of soot that is trapped in the regeneration filter. This also helps with the noise output as the combustion chambers are heating up.

In sum, you turn your engine switch on and wait those few seconds for the light to go off. Immediately, an electric current passes through the heating element and the glow plugs heat the fuel. After the light goes off and you start your engine, all the processes described above occur within your engine.

When Should You Replace Your Glow Plugs?

There is a whole relay of glow plugs inside your engine, waiting to heat the diesel fuel to start the whole process of ignition. As mentioned before, the number of glow plugs will depend on the number of cylinders in the engine. If you start having problems with your glow plugs, it could be just one plug or it could be the electrical system that connects the glow plugs.

Here are some signs that there are problems with your glow plugs.

A Warning Light Goes On

Many diesel-powered vehicles come equipped with sensors that will notify you of a problem. You may have a Check Engine light or even a Check Glow Plugs light.

A faulty glow plug will illuminate the Check Engine light, as will numerous other problems, so this would warrant investigation and does not guarantee the problem is with the glow plugs.

It’s Difficult to Start Your Engine

Heating glow plugs are what is required to generate the necessary heat to ignite the fuel. Your vehicle won’t start without this heat. It can, however, be the battery and the fuelling system, so these need to be checked first.

Black Smoke

You should never get black smoke from the exhaust pipe if your diesel engine is functioning properly with proper combustion processes. If you have a malfunctioning glow plug, you may get improper heating of the fuel in some cylinders causing black smoke. 

Again, malfunctioning glow plugs are not the only possible reason for black smoke, so don’t rule out other possibilities.

Weak Acceleration or Engine Misfiring

Your truck will still start, even with a bad glow plug. Your acceleration will be affected however since not all cylinders are receiving the heated fuel in the way they should. You may also have problems with your engine misfiring.

Once again, don’t rule out other problems unless you have other symptoms listed here. 

Poor Fuel Economy

A stressed-out diesel engine, just like a gasoline engine, will perform poorly and consume more fuel. Replacing a faulty glow plug with a good one will fix this problem of excessive use of diesel fuel.

What To Do If Your Diesel Truck is Having These Problems

You should always get regular diesel engine maintenance. If your mechanic determines one glow plug isn’t working properly, you might as well replace all of your glow plugs, because you can be certain the others will likely start to fail soon.

One of the main issues with diesel engines can be the electrical system. Any misfunction in this system may mean your glow plugs are not functioning properly.

Getting a qualified mechanic to do your diesel truck repair and maintenance can prevent a lot of problems. Contact us today if you are experiencing any of the problems listed above and we’ll check to see if it’s a simple problem like glow plugs and get everything in tiptop shape for you.

The Benefits of Buying a Diesel Car

The Benefits of Buying a Diesel Car

Are you in the market for a new car but not sure whether diesel, petrol, or electrical is your best choice? There are, of course, a range of different factors that should be considered when making this decision. These include what you need the car for, how much your...

How to Clean Your Diesel Engine Like a Pro

How to Clean Your Diesel Engine Like a Pro

When was the last time you cleaned your diesel engine? While your vehicle’s diesel engine boasts lower emissions and better fuel economy, it needs regular cleaning. Failing to clean your vehicle’s engine bay may increase the risk of a fire breakout. Most of the...

What to Expect From the 2022 Toyota Tundra Diesel

What to Expect From the 2022 Toyota Tundra Diesel

The Toyota Tundra is a popular truck that has been around for a while. It's time for an update. The new diesel-powered Tundra will be available in 2022 with some great features. One of the most anticipated features is the fuel economy - 18 MPG combined and 32 highway...

5 Things to Know Before Buying a Diesel Truck

5 Things to Know Before Buying a Diesel Truck

Are you thinking about buying a diesel but aren’t sure where to start? Maybe you have friends who’ve been buying diesel trucks, and you want to know what all the fuss is about. Maybe you’ve been seeing more diesels driven around your area, and you’re curious to...

Diesel Truck Care: Engine Maintenance Tips

Diesel Truck Care: Engine Maintenance Tips

Today's vehicles are a big investment whether they're diesel or gasoline-powered. The last thing you want is a huge repair bill because you failed to keep up with regular auto maintenance. Do you own a powerful diesel truck? As with any vehicle, diesel truck care...

How to Make Your Brakes Last Longer

How to Make Your Brakes Last Longer

When you are driving down the road, you trust that every part of your car works. You believe that when you step on the brakes, the car will stop.  But sometimes, parts malfunction. Brakes don't work, at least not as quickly or efficiently as they should....

Top 7 Engine Maintenance Tips

Top 7 Engine Maintenance Tips

Across the country, there are more than seven million diesel engines in operation. This fuel type allows vehicles to have more power which translates to being able to tow with more capacity and often last much longer.  But the owner of a diesel-fueled vehicle has...

8 Signs You Need to Buy New Diesel Truck Tires

8 Signs You Need to Buy New Diesel Truck Tires

A tire blowout is one of the scariest things a motorist can experience while out on the roadway. It's the result of a sudden loss of inflation pressure, which can happen if the tires on your truck are worn and torn. If you drive a diesel truck, you'll want to keep it...

7 Signs Your Truck Needs a New Diesel Engine

7 Signs Your Truck Needs a New Diesel Engine

Diesel truck owners are used to their trucks taking care of them. Whether it is long-haul, farm work, transporting construction equipment or even getting you to the job site every day. Your truck is essential to your success. That is why taking care of your truck...

Diesel Repair Services: The Complete Guide

Diesel Repair Services: The Complete Guide

Wondering about diesel repair services? For instance, what are the most common repairs truck drivers need? More importantly, how can you tell if your diesel truck needs repairing? You'll find all these answers and more in the guide below. To be specific, this guide...

3 Signs You Need Diesel Repair Services

3 Signs You Need Diesel Repair Services

Is your Diesel engine stalling out? Making weird noises? Are you worried that you might be making the problem worse, or that you could damage your engine attempting to figure out what's wrong? Well, let us help you - look for these 3 simple signs that you need to...

Can You Use Biodiesel on Your Diesel Engine?

Can You Use Biodiesel on Your Diesel Engine?

Do you drive a diesel car or truck? If so, you're part of a growing trend. The popularity of vehicles powered by this alternative fuel is steadily on the rise. And, there are more options than ever before for clean diesel vehicles!  Diesel engines make for quiet, fun...

8 Common Ways of Harming a Diesel Engine

8 Common Ways of Harming a Diesel Engine

Diesel engines are tough and more fuel-efficient than those that run on gasoline. However, that doesn't mean you don't need some care and attention from time to time. If you are pushing your engine hard on the daily and driving in some tough conditions, it may be time...

10 Common Reasons for Diesel Truck Repairs

10 Common Reasons for Diesel Truck Repairs

Are you having trouble with your diesel engine? A diesel engine has some very particular problems unique to its intricate design. You need to identify them and fix them quickly, or you can cause lasting damage to the vehicle.  We are here to help. Below, we have...

9 Tips to Improve Diesel Engine Performance

9 Tips to Improve Diesel Engine Performance

Even as automobile sales continue to dwindle throughout the country, diesel sales continue to climb. If you're someone who drives a vehicle with a diesel engine, then you're probably on the road a lot. And because of that, you want to make sure that your engine...