How to Remove a Diesel Injector: A Step-by-Step Guide If you own a diesel engine, then it likely has injectors. That's because diesel engines need unique injection systems to operate. These injection systems are what give diesel engines their name. However, they are also prone to failure in many cases. Injectors can fail in a variety of ways and under different circumstances. They can become clogged or crack over time, but they can also become defective because of bad design or construction flaws. When this happens, the injector needs to be replaced before it causes further problems with your car. Replacing a defective injector is not overly difficult for most people with some automotive knowledge and skillset. Removing the old one and installing the new one is pretty straightforward once you understand the process involved - which we'll explore in this article below. Why Do Diesel Injectors Fail? Before we look at how to replace diesel injectors, let's take a closer look