These little guys are basically tiny electric heaters inside your engine. They heat up the combustion chamber—the space where the fuel and air mix—to get things started, especially when it’s cold. They’re a resistive heater, meaning electricity flows through them and creates heat. It’s a pretty simple idea, but crucial. They're most important in diesel engines. Diesels don’t have a spark plug like a gas engine. Instead, the extreme heat from the glow plug ignites the fuel. When you turn the key, the glow plugs preheat that air, and that makes it possible for the diesel fuel to ignite on compression. They usually only run for a short time when starting, and sometimes briefly after, depending on the engine and the temperature. After the engine is warm, they typically aren’t needed. If a glow plug goes bad, your engine will be really hard to start, especially in cold weather. It might start eventually, but it’ll be struggling. You’ll notice if it's taking a long time to fire up, or if it's running really rough when it does. They act like a shield against cold starting issues. If multiple plugs fail, it may not start at all. They’re relatively inexpensive parts, and replacing them proactively can save you a lot of headaches down the road. We often see folks get a set of them replaced together, since they tend to wear out around the same time. You can find glow plugs and a lot of other engine parts at places like Fixparts Online, but we keep a good stock here too. Premium parts, premium warranty: Glow plug (MPN 4.67507) is covered for 12 months!

About DT

DT is a reputable German brand specializing in high-quality spare parts for commercial vehicles. Based in Germany, DT provides reliable components that support the durability and performance of automotive fleets.

Why Choose DT?

• We have a huge selection of parts, so you’re likely to find what you need, fast. • Our parts are high quality and built to last, saving you money in the long run. • We offer fast, reliable shipping right to your door. • Our customer service team is friendly and knowledgeable – we're here to help! DT delivers excellence, FixParts Online delivers to your door.