A diesel engine uses glow plugs instead of spark plugs to get ignition in the combustion chamber. The diesel engine must be hot inside the chamber for combustion to start. The glow plugs warm the combustion chamber when you first turn the key or press the start button. This helps your diesel engine to fire up. Village Diesel Works advises that the glow plugs are only used at ignition. As such, they last longer than spark plugs do. This being said, they can go bad. Here are the signs of bad glow plugs.
Hard Starts
Naturally, if one or more of the glow plugs is malfunctioning, the combustion chamber may not get to the temperature that it needs to get to to fire up the air and fuel and start your diesel engine. If you are having difficulties getting your diesel engine started and it isn’t an electrical problem, i.e., the battery, or a fuel-delivery problem, it’s possible that it’s time to replace the glow plugs.
Misfiring Engine
Specifically, the glow plugs heat the combustion chamber up to 450 degrees Fahrenheit. This is much hotter than the maximum temperature of the gasoline engine, which should not be higher than 220 degrees Fahrenheit. If the glow plugs are unable to get the combustion chamber to this temperature, your engine may misfire even if you get it started because there isn’t enough heat.
Rough Idling
Worn glow plugs can also make your diesel engine idle roughly, again, because the temperature is not hot enough. This impedes the compression and combustion. When these two things are affected, the engine idle is affected. Unfortunately, you will continue to have problems with the engine idle until you replace the malfunctioning glow plugs. Even one glow plug can cause a problem.
Reduced Fuel Efficiency
Naturally, if your diesel engine is not running efficiently, you will see a noticeable reduction in its fuel efficiency. When the engine is not running at the right temperature, it is not able to run inefficiently. This is what causes the engine performance issues and rough idling discussed above. Again, replacing the faulty glow plugs will restore your engine’s performance and its fuel efficiency.
White Smoke
Finally, if you see white smoke coming out of the tailpipe when you first fire up your diesel engine, this is a sign that the combustion chamber is not as hot as it should be. The damaged glow plugs may also produce black smoke if they affect the balance of air and fuel in the combustion chamber.
Call Village Diesel Works in Woodbury, MN, today if your diesel truck or other diesel automobile is having any of the problems listed above. We will inspect and test the glow plugs and replace them if necessary. If the glow plugs are not the problem, we will find the problem and fix it.