Can Faulty Glow Plugs Cause Loss Of Power? What You Never Knew

So you may be wondering – “Can faulty glow plugs cause loss of power?”

In general, glow plug issues involve a number of things, and this includes faulty engines. When you have a problem with your glow plugs, the heat required to achieve diesel combustion is not met. Thus, your engine tends to misfire.

And when things get worse, your engine will present a weaker performance.

Today, we will cover important issues around glow plugs and loss of power. We will talk about the symptoms of damaged glow plugs, so you can be prepared, as well as the other effects of using glow plugs that are no longer performing as they should.

Let’s get right into it.

can faulty glow plugs cause loss of power

Can Faulty Glow Plugs Cause Loss Of Power?

When you hard start engines, your glow plugs may fail over time. You may need to hard-start your engine because of a problem with it, or you are unable to keep it running once idle.

When you have faulty glow plugs, acceleration is impacted. Glow plugs that malfunction tend to decrease the acceleration and power in your engine. Misfiring may occur, which means the glow plugs cannot give the extra heat required to burn diesel effectively. So, the engine misfires. With misfiring, other conditions may occur including power loss, reduced fuel efficiency, and difficulty with accelerating.

Problems With Faulty Glow Plugs

Aside from power loss, there are a few other things to be concerned about when it comes to faulty glow plugs. These include a knocking, which does not go away even when you have the engine warmed up. The chamber and fuel are very hot for the combustion, and at the same time, the engine is unable to generate the ample compression needed.

When you have faulty glow plugs, this can lead to an interference with the delicate diesel combustion process. Hence, black smoke may come from the tailpipe. This means that the glow plugs are not working as they should, which then impacts the other parts of the engine.

Thus, if you have bad glow plugs, it can be difficult to start the vehicle. While you may be able to start it, this can take many attempts. But only if the temperature outside is ideal. But if it is very cold outside and it is below freezing temperature, it is next to impossible to start the engine.

On the other hand, having faulty glow plugs will cause the engine to not start at all.

With this in mind, yes, faulty glow plugs prevent the engine from starting. It also impacts performance since they are unable to give the right amount of heat to your combustion chamber. This weakens the performance of your engine, which then works harder than it should just to meet the difficult road conditions. Overall, fuel efficiency is impacted negatively.

When you notice a number of symptoms such as a faulty engine, slow-starting engine, decreased fuel efficiency, failure to start your engine, as well as a very white smoke emitted, then it may be time to replace your glow plugs.

You cannot even attempt to start a diesel engine without glow plugs. What happens is there is insufficient heat needed to even ignite your engine. You need good-working glow plugs that will generate extra heat to be able to run your diesel engine.

What To Do With Concerns About Bad Glow Plugs

You may notice that your engine is producing a knocking sound. When this happens, it means that there is an incorrect mixture of air and fuel. As a result, fuel burns unevenly, which causes this knocking sound. If you do not address this at all, the piston and cylinder wall will accumulate damages.

But there is something else to be concerned about aside from the knocking sound. The upper cylinder head may lack lubrication, which can also cause these knocks.

You will know when your glow plugs have gone bad when there are a few symptoms such as black or white smoke, rough idling and engine misfiring. In addition, faulty glow plugs can affect the diesel combustion process. So, the engine ends up producing black or white smoke from the tailpipe. This is a clear sign that you need to have the glow plugs replaced as soon as possible.

Read More: Can You Replace Just One Glow Plug? Important Things To Know 

Additional Information On Faulty Glow Plugs

Aside from a faulty glow plug, there is also a glow plug relay failure that you should think about. The relay should lose its performance over time because of natural wear and tear. Other things that cause the accelerated wear and tear are misfiring injectors, fluctuation with the electrical currents and extreme temperature.

You can also take a look at symptoms of a poor glow plug relay such as white exhaust smoke and hard starting. The smoke comes from the diesel leaking into your exhaust, which is where the burning happens. The difficulty with starting the engine means that the engine is unable to start efficiently even when it is warm and does not start at all in the cooler weather.

In case you have a vehicle with four cylinders, one glow plug that has gone bad will result in a slightly difficult hard-starting. But with two glow plugs broken, hard starting is tough, as well as operating the vehicle. And when you have three non-working glow plugs, it will not start at all nor run.

So, when you have bad glow plugs, be sure to replace the set. Check the engine light or diagnostic trouble code. Make sure you have a diagnostic scan tool to help you determine the problem more efficiently.

Final Thoughts

When you observe these symptoms, it is very important to have your glow plugs replaced. Do keep in mind that power loss is a result of using faulty glow plugs. This is why to avoid this issue and further problems over time, you should get your glow plugs replaced and have the peace of mind when driving.

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