How to Spot Clogged Diesel Fuel Injectors and Clean Them

One perk of owning a diesel engine is the comfort of enjoying a smooth ride. You’re in tune with your vehicle after a period, resulting in you being able to tell when there’s a slight change in sound or performance. For instance, if you spot clogged diesel fuel injectors, you might notice a decrease in performance or unusual engine noise.

To a large extent, diesel fuel injector makes this possible. They are one of the most essential yet unseen parts that ensure your engine receives the correct mixture of fuel and air.

If you’re wondering how to spot clogged diesel fuel injectors, it’s important to understand their role in maintaining this balance. A diesel fuel injector works by allowing smooth passage of fuel into the cylinder of the engine through a nozzle so the internal combustion process can begin.

The tricky part is they must deliver fuel at the right time, in the right amount, at the correct pressure, angle, and spray pattern.

Knowing the signs of a dirty or clogged fuel injector, such as poor engine performance or fuel inefficiency, and how to clean them can save you a lot of irritation, time, and money. If you’re unsure whether your fuel injectors are clogged, it’s essential to spot clogged diesel fuel injectors early to avoid further engine damage.

Spotting Clogged Diesel Fuel Injector Symptoms 

Diesel fuel injector clogs occur when sediment and dirt build up between the pintle shaft and injector body, which restricts normal flow. One of the best ways to spot clogged diesel fuel injectors is by looking for signs such as rough idling, poor engine performance, and reduced fuel efficiency.

Below are some signs that can help you identify if there is a clog or dirt on your diesel engine ’s injectors:

1. Idling Gets Fuzzy

Is your engine cranking and becoming difficult to start, or does your vehicle sputter and shake when you’re at a stop sign or sitting in traffic?

Chances are your diesel engine is not getting enough fuel or an uneven amount of fuel and air, which causes rough idling. Making the RPM drop below optimal and engine noise feels like running out of gas on a hill.

Your Diesel fuel injector might be dirty and needs your attention. One way to spot clogged diesel fuel injectors is by noticing these signs of poor engine performance, which can lead to reduced efficiency and potential damage if not addressed.

2. Vibration and Misfiring Engine 

When there is a slight delay in acceleration when pedaled, it means the diesel engine does not get an adequate supply of fuel. One common reason for this issue is when you spot clogged diesel fuel injectors, which can disrupt the fuel flow. This results in a lack of combustion chamber heat, potentially leading to misfiring or a sudden drop in a quick movement.

3. Fuel Leak & Diesel Fuel Smell

We may perceive the smell of fuel caused by a leak while driving. There’s a chance it’s because of a faulty injector that allows fuel to escape, or two injectors are clashing.

4. Inadequate Fuel Economy

A clogged fuel injector can lead to a significant drop in fuel economy. Your car consumes more fuel than it should. Making the engine not get the required amount of fuel it needs for combustion.

This places more demand on the injector to supply it with additional fuel and leads you to fill up more than necessary.

5. Poor Emissions

Fuel injectors become clogged because of uneven and incomplete fuel burns, which lead to increased emissions.

It’s related to dark clouds around the exhaust, with white smoke coming out.

Above are symptoms that show your fuel injectors might be dirty, but in reality, other factors can cause one or more of these symptoms to emerge.

Are you unsure if the symptoms you’ve observed in your diesel engine are related to a clogged fuel injector?

You can call Phoenix Diesel Repairs, based in Arizona, who can get you the right diagnosis.

How to Test Your Diesel Fuel Injectors

To be sure that your fuel injectors are not dirty, here are various methods, including how to spot clogged diesel fuel injectors, which vary in difficulty and types of equipment to use:

1. Listening to Your Injectors

This is one of the easiest methods to test your diesel engine injector. It works by grabbing a short length of hollow rubber pipe, placing one end on the injector, and listening from the far end. 

Another way is by placing the end of a long screwdriver or metal rod against an injector, and then putting your ear to the far end.

Hearing clicks traveling up through the rubber or screwdriver, then the injector is working.

2. Test Resistance With an Ohm Meter

Buy an ohmmeter getting from any auto part house. Check the usage of each injector cylinder if there is proper resistance.

Resistances of diesel injectors are between 0.4 and 0.8 ohms and some 10 to 18 ohms, depending on your settings

3. Temperature Check

Performing a rough temperature check can help determine which is faulty.

Flick drops of water on each cylinder from an engine that just got started. As the engine warms up, the functioning cylinder warms up while the faulty one remains cold.

Cleaning a Clogged Diesel Fuel Injector

Knowing the symptoms of the complicated dance that goes on in your fuel injection system makes it easy to see how bad, clogged, or dirty fuel injectors can throw a wrench in your diesel engine! One of the key things to keep in mind is how to spot clogged diesel fuel injectors early on.

These are a few ways that will help with unclogging your diesel fuel injectors:

1. Using Diesel Fuel Additives

They help your engine burn fuel smoothly and prevent build-up around the injectors.

Our opinion: Claiming to clean or unclog a clogged fuel injector while it is in the engine cannot be farther from the truth. The products must get inside the injector. 

Common sense suggests that for you to clean something, you need access to it, which they don’t because the injectors are in the engine.

They are useful for preventing clogging, but not to unclog or clean injectors.

2. Fuel Injection Cleaners and Fuel Injector Cleaning Kit

Diesel injector cleaners work by loosening all the debris from the diesel fuel. It pumps all the loosened debris back through the pathway of the fuel injector but it does more harm than good.

Fuel injector cleaning kit helps remove built-up residue, which is easier to see and cheap and easy to use. It helps you clean stubborn clogs out of your fuel injectors. You must make sure the kit you use is for diesel injectors.

The above solutions don’t come without their cons, though. The only guaranteed way to unclog a clogged injector is by removing the injectors from the engine.

Once removed, you drop or mail the injectors to a professional injector cleaning service like Phoenix Diesel Repair . If you are in Phoenix , Arizona, contact Phoenix Diesel Repair diesel engine experts for help.