The Ultimate Guide to Diesel Engine Sensors

The components are small, but critical. Your diesel engine sensors are responsible for tracking information about the system temp, pressure, fuel delivery, airflow, and other operating conditions. That way, the engine's control system can make adjustments and give you a head’s up when something isn't right.

Unfortunately, when a sensor starts to fail, the problem isn't always obvious. Being able to recognize bad sensor symptoms can help you diagnose problems sooner. The more you know, the easier it’ll be to avoid the costs of replacing parts that haven’t actually failed.

What Do Diesel Engine Sensors Do?

Sensors are there to continuously monitor your engine’s operating conditions, and they work to send info to the engine control module (ECM). From there, your fuel injection, timing, airflow, and emissions systems can all be kept in check.

 You’ll have different combinations of diesel engine sensors for different applications. Some of the most common are your coolant temperature sensors, oil pressure sensors, fuel pressure sensors, boost or manifold pressure sensors, crankshaft and camshaft position sensors, and intake air temperature sensors. They’re built to be tough, but since the components are constantly dealing with heat and vibration, they can eventually wear out or malfunction. When that happens, your ECM could start making adjustments you don’t actually need. That’s why it’s important to know when the sensor itself might be on the way out. 

Recognizing Bad Sensor Symptoms

One of the tricky things about sensor problems is that the symptoms can look like something entirely different is going on with your engine. Hard starts, rough idling, fuel economy that’s getting worse, loss of power, unusual exhaust, warning lights, and inconsistent performance can all be bad sensor symptoms. It just depends on what’s failed.

For example, a faulty coolant temperature sensor can give you an engine temperature reading that’s completely off. In turn, that will impact how your engine is managing fuel and some of its other operating parameters. Or take a malfunctioning boost pressure sensor. That can mess with your turbochargers and potentially lower your power.

Position sensors are also important. Your crankshaft and camshaft sensors help the engine figure out where the internal components are in their operating cycles. If one begins to fail, you could be looking at hard starting, stalling, or even an engine that refuses to start. But since these types of issues overlap with other mechanical problems, replacing a sensor based solely on a symptom isn't always the best approach. It’s worth keeping in mind that it might only be the sensor to blame, but that doesn’t mean you shouldn’t take a closer look.

Diagnose Before You Replace

Proper diagnostics are crucial when you’re troubleshooting diesel engine sensors. Running a diagnostic scan can flag fault codes for a particular sensor or circuit. On the other hand, a physical inspection can help you spot loose connections, damaged wiring, or corrosion.

In some cases, the sensor itself isn't the problem. A bad electrical connection can produce the same sort of bad sensor symptoms as a failed component. So it's always worth testing the system before replacing parts. Having the appropriate diagnostic equipment and knowing how to interpret the results can make repairs a lot faster. Plus, it’ll help you avoid the frustration of replacing an expensive component only to learn that the original problem was somewhere else.

Find the Diesel Parts You Need at Young & Sons

When you're dealing with bad sensor symptoms, having a knowledgeable parts supplier can make all the difference. At Young & Sons, we work with diesel engines every day, so our team has the practical experience you need to find the right replacement.

If your testing confirms that a sensor has failed or is no longer providing accurate readings, it’s time to opt for a new part. We carry diesel engine sensors and all of the other components heavy-duty equipment needs to keep running.

Our detailed product listings can help you make more informed purchasing decisions. And if you're unsure about what you need, our team is available to help with more than just looking up a part number. We can actually talk you through the problem.

Whether you're replacing a failed sensor, stocking your shop, or tackling a larger diesel repair, most orders placed before 4 p.m. EST ship the same day, Don't let mysterious warning lights or performance problems keep your equipment down. Diagnose the problem, find the right replacement, and get back to work with Young & Sons.