Joseph Weaver Subaru vehicles are known for their reliability and excellent performance. However, even the best-engineered vehicles can experience issues, and one of the most common issues that Subaru owners face is a faulty coil pack. The coil pack is a critical component of the engine, responsible for delivering the electrical charge that ignites the fuel in the cylinders. When the coil pack fails, it can result in an engine misfire, poor performance and a host of other problems. Before visiting a mechanic, car enthusiasts and DIY mechanics can try to test the coil pack using a multimeter. In this article, we will provide a step-by-step guide on how to test a Subaru coil pack with a multimeter like a pro.
Introduction to Subaru Coil Pack
Before we dive into the testing process, it is important to understand what a coil pack is and its function in the engine. A coil pack is a collection of ignition coils that work together to produce the high-voltage energy that is needed to create a spark for each cylinder. The coil pack gets its energy from the battery, and the signal is sent to the engine control module (ECM) through the spark plug wires. The ECM regulates this electricity to create the perfect conditions for combustion in the engine cylinders.
Symptoms of a Faulty Coil Pack
If you’re experiencing any of the following symptoms with your Subaru engine, it could indicate that the coil pack is faulty and needs testing:
- Engine misfire or poor acceleration
- Unusual engine sounds or vibrations
- Decreased fuel economy
- Difficulty in starting the car
- Illuminated check engine light or blinking ABS light
Tools Required for Testing the Coil Pack
Now that we know what the symptoms of a faulty coil pack are let’s look at the tools needed to test the coil pack.
- A multimeter
- Safety goggles
- Insulated pliers
- A flathead screwdriver
- A new spark plug wire
Step-by-Step Guide on How to Test a Subaru Coil Pack Using a Multimeter
Let’s dive into the testing process of the Subaru coil pack:
- Put on safety goggles since you will be working on the engine while it’s running.
- Start the engine and allow it to warm up for a few minutes.
- Pop the hood and locate the coil pack on top of the engine.
- Using an insulated plier, gently pull off each spark plug wire from the coil pack. Be careful not to pull on the wire itself since this may cause damage.
- Take a new spark plug wire and insert one end into the coil pack. You can use the screwdriver to push it in firmly.
- Touch one end of the multimeter to the contact at the ignition coil’s centre terminal.
- Connect the other end of the multimeter to the engine block.
- Turn off all the electrical components in the car to enable accurate readings.
- At idle mode, the reading on the multimeter should be around 12 volts. If the reading is below or above this range, you may have a bad coil pack.
- Next, rev the engine until it reaches about 1500 RPM. The multimeter should register the voltage at around 12 volts. If the voltage reading fluctuates or falls outside the 11 to 15 volts range, it indicates a bad coil pack.
- Repeat steps 6-10 for every cylinder.
Understanding the Multimeter Readings and What They Mean
The multimeter readings during testing will vary between different models, but somewhere between 11 and 15 volts is ideal. Any value outside that range signals that there is a problem with the coil pack. Once testing is complete and a problem is detected, you should Replace the faulty coil pack with an OEM or a high-performance aftermarket alternative.
Troubleshooting Common Issues Encountered During the Testing Process
Some of the issues that Subaru car owners and DIY mechanics encounter while testing their vehicle’s coil pack include:
- Difficulty in accessing the coil pack: Some Subaru models are designed with tight spaces, especially with turbocharged engines. In such cases, give yourself ample time since the accessing the coil pack may take a while.
- The multimeter readings fluctuating: This could mean that there is a problem with the internal coil pack.
Frequently Asked Questions
- Why is my Subaru engine misfiring?
A: If your Subaru engine is misfiring, it could be due to a faulty coil pack.
- What should I do if the coil pack is faulty?
A: Replace the faulty coil pack with an OEM or high-performance aftermarket alternative.
- Can I replace the coil pack myself?
A: Yes, you can replace the coil pack yourself if you have some experience working with cars.
- What is the average lifespan of a Subaru coil pack?
A: The lifespan of a Subaru coil pack varies depending on usage, but on average, they last between 60,000 and 100,000 miles.
Conclusion
The coil pack is a critical component of the Subaru engine, responsible for delivering the electrical charge that ignites the fuel in the cylinders. When a coil pack fails, it results in an engine misfire, poor performance and other problems. By following the step-by-step guide on how to test a Subaru coil pack with a multimeter, car enthusiasts and DIY mechanics can troubleshoot the issue themselves and save money on mechanic bills. Remember to always replace a bad coil pack with an OEM or high-performance aftermarket alternative. Happy troubleshooting!
