Hey guys! Are you having trouble with your 2004 Infiniti G35? Is your engine misfiring, or is your car just not running as smoothly as it used to? Well, the problem might be your ignition coils! Don't worry, you've come to the right place. This guide will walk you through everything you need to know about ignition coils for your Infiniti G35 2004, from understanding what they do to troubleshooting common issues and even replacing them yourself. Let's dive in!

Understanding Ignition Coils

Ignition coils are a crucial part of your car's ignition system. In simple terms, they transform the low voltage from your car's battery into the high voltage needed to create an electrical spark in the spark plugs. This spark ignites the air-fuel mixture in the engine cylinders, which then powers your car. Without properly functioning ignition coils, your engine simply won't run correctly.

Think of ignition coils as tiny transformers. Your car's battery typically operates at 12 volts. The ignition coil boosts this voltage to anywhere between 20,000 to 50,000 volts! This high voltage is then sent to the spark plugs, creating the spark that ignites the combustion process. The Infiniti G35 2004, like many modern cars, uses a coil-on-plug (COP) system. This means each spark plug has its own dedicated ignition coil sitting directly on top of it. This design improves efficiency and reduces the chances of voltage loss compared to older systems that used a single coil and distributor.

The number of ignition coils in your Infiniti G35 2004 corresponds to the number of cylinders in your engine. Since the G35 typically comes with a V6 engine, you'll find six ignition coils. Each coil is responsible for providing the spark to its respective cylinder. When one or more of these coils start to fail, you'll likely experience noticeable performance issues.

Why Ignition Coils Fail

Several factors can contribute to ignition coil failure. Heat is a major enemy. Ignition coils operate under extreme temperatures, and over time, this heat can degrade the coil's internal components. Another common cause is vibration. The constant vibration from the engine can also weaken the coil's structure, leading to cracks or other damage. Moisture can also cause problems. If moisture gets inside the coil, it can cause short circuits and corrosion, ultimately leading to failure.

Old age is also a factor. Like any other car part, ignition coils have a lifespan. Over time, the insulation can break down, and the internal components can wear out. Lastly, problems with other engine components, such as faulty spark plugs or wiring issues, can put extra stress on the ignition coils, causing them to fail prematurely. Regular maintenance, such as replacing spark plugs at the recommended intervals, can help prolong the life of your ignition coils.

Symptoms of Failing Ignition Coils

Recognizing the signs of failing ignition coils early can save you from more serious engine problems down the road. Here are some of the most common symptoms to watch out for:

• Engine Misfires: This is one of the most common and noticeable symptoms. A misfire occurs when one or more cylinders in your engine don't fire properly. This can cause the engine to run rough, hesitate, or even stall.
• Rough Idle: If your car idles roughly, especially when stopped at a light or in park, it could be a sign of a failing ignition coil. The engine may shake or vibrate excessively.
• Reduced Power: You might notice a decrease in acceleration and overall engine power. The car may feel sluggish, especially when going uphill or trying to pass another vehicle.
• Poor Fuel Economy: Failing ignition coils can cause the engine to burn fuel less efficiently, resulting in a noticeable drop in your gas mileage.
• Check Engine Light: The check engine light will often illuminate when there's a problem with the ignition system. The car's computer detects the misfires and throws a code. You'll need an OBD-II scanner to read the code and confirm the issue.
• Difficulty Starting: In some cases, failing ignition coils can make it difficult to start your car. The engine may crank for a longer time than usual, or it may not start at all.
• Engine Stalling: If the ignition coils are severely failing, the engine may stall, especially at low speeds or when idling.

If you experience any of these symptoms, it's a good idea to have your car inspected by a mechanic as soon as possible. They can diagnose the problem and recommend the appropriate repairs.

Diagnosing Ignition Coil Issues

So, you suspect your Infiniti G35 2004 has a bad ignition coil? Here's how you can diagnose the issue:

1. OBD-II Scanner: The first step is to use an OBD-II scanner to read the diagnostic trouble codes (DTCs) stored in your car's computer. Common codes associated with ignition coil problems include P0300 (random misfire), P0301 (misfire in cylinder 1), P0302 (misfire in cylinder 2), and so on. These codes will give you a starting point for your diagnosis.
2. Visual Inspection: Carefully inspect each ignition coil for any signs of damage, such as cracks, burns, or corrosion. Also, check the wiring and connectors for any loose connections or damage.
3. Coil Swap: This is a common method for pinpointing a faulty ignition coil. Swap the suspect coil with a known good coil from another cylinder. For example, if you have a P0301 code (misfire in cylinder 1), swap the ignition coil from cylinder 1 with the coil from cylinder 2. Clear the DTCs with your OBD-II scanner and then start the engine. If the misfire moves to cylinder 2 (P0302), then you've confirmed that the ignition coil you swapped is the problem.
4. Multimeter Testing: You can use a multimeter to test the primary and secondary resistance of the ignition coils. Compare the readings to the manufacturer's specifications. A significant deviation from the specified values indicates a faulty coil.
5. Spark Plug Inspection: Examine the spark plugs for signs of wear, damage, or fouling. A bad spark plug can put extra stress on the ignition coil, causing it to fail prematurely. Replace any worn or damaged spark plugs.

If you're not comfortable performing these tests yourself, it's best to take your car to a qualified mechanic. They have the tools and expertise to accurately diagnose the problem and recommend the appropriate repairs.

Replacing Ignition Coils: A Step-by-Step Guide

Replacing the ignition coils on your Infiniti G35 2004 is a relatively straightforward job that most DIYers can handle. Here's a step-by-step guide to help you through the process:

Tools and Materials You'll Need

• New ignition coils (purchase quality replacements)
• Socket set
• Ratchet
• Extension bar
• Screwdriver (usually a flathead)
• OBD-II scanner (to clear codes)
• Work gloves
• Safety glasses

Step-by-Step Instructions

1. Safety First: Before you start, make sure the engine is cool. Disconnect the negative terminal of the battery to prevent any electrical accidents. Wear safety glasses and work gloves.
2. Locate the Ignition Coils: The ignition coils are located on top of the engine, directly above the spark plugs. They're usually covered by a plastic engine cover. Remove the engine cover by unscrewing or unclipping it.
3. Disconnect the Electrical Connector: Each ignition coil has an electrical connector attached to it. Gently disconnect the connector by pressing the release tab and pulling it off. Be careful not to damage the connector.
4. Remove the Ignition Coil: Use a socket and ratchet to remove the bolt or bolts that secure the ignition coil to the engine. Once the bolts are removed, gently pull the ignition coil straight up to remove it from the spark plug well.
5. Install the New Ignition Coil: Install the new ignition coil by inserting it into the spark plug well and aligning the bolt holes. Tighten the bolts to the specified torque. Be careful not to overtighten them.
6. Reconnect the Electrical Connector: Reconnect the electrical connector to the ignition coil. Make sure it clicks into place securely.
7. Repeat for Remaining Coils: Repeat steps 3-6 for all the ignition coils you're replacing. It's often recommended to replace all the ignition coils at the same time to ensure consistent performance.
8. Reinstall the Engine Cover: Reinstall the engine cover and secure it with the screws or clips.
9. Reconnect the Battery: Reconnect the negative terminal of the battery.
10. Clear the Codes: Use your OBD-II scanner to clear any diagnostic trouble codes (DTCs) that may have been stored in the car's computer.
11. Test Drive: Start the engine and take the car for a test drive to make sure it's running smoothly. Listen for any misfires or other unusual noises.

If you encounter any difficulties during the replacement process, consult a repair manual or seek assistance from a qualified mechanic.

Choosing the Right Ignition Coils

When it comes to replacing your Infiniti G35 2004's ignition coils, you have several options to choose from. Here's a breakdown of the different types of ignition coils and what to consider when making your selection:

• OEM (Original Equipment Manufacturer) Coils: These are the same coils that came with your car from the factory. They're typically the most reliable option, as they're designed specifically for your vehicle. However, they can also be the most expensive.
• Aftermarket Coils: Aftermarket ignition coils are made by third-party manufacturers. They can be a more affordable alternative to OEM coils, but the quality can vary significantly. It's important to choose a reputable brand with a good track record.
• Performance Coils: Performance ignition coils are designed to provide a stronger spark than OEM coils. This can improve engine performance, especially in modified vehicles. However, they may not be necessary for a stock Infiniti G35.

When choosing ignition coils, consider the following factors:

• Quality: Look for coils made from high-quality materials that can withstand the extreme temperatures and vibrations in your engine.
• Reliability: Choose a brand with a reputation for reliability. Read online reviews and ask for recommendations from other Infiniti G35 owners.
• Price: Compare prices from different vendors to find the best deal. However, don't sacrifice quality for price. It's better to spend a little more on a reliable coil than to save money on a cheap one that will fail quickly.
• Warranty: Check the warranty offered by the manufacturer. A longer warranty indicates that the manufacturer has confidence in the quality of their product.

Preventing Future Ignition Coil Failures

Here are some tips to help you prevent future ignition coil failures and extend the life of your ignition system:

• Replace Spark Plugs Regularly: As mentioned earlier, worn or damaged spark plugs can put extra stress on the ignition coils. Replace your spark plugs at the intervals recommended in your car's owner's manual.
• Keep the Engine Clean: A clean engine runs cooler, which can help prolong the life of the ignition coils. Regularly clean the engine bay to remove dirt and debris.
• Avoid Short Trips: Short trips can be hard on the engine, as it doesn't have enough time to warm up properly. This can lead to increased wear and tear on the ignition coils.
• Address Engine Problems Promptly: If you notice any engine problems, such as misfires or rough idling, have them addressed promptly. These problems can put extra stress on the ignition coils and cause them to fail prematurely.
• Use Quality Fuel: Using high-quality fuel can help prevent deposits from forming on the spark plugs and ignition coils. Follow the fuel recommendations in your car's owner's manual.

By following these tips, you can help keep your Infiniti G35 2004 running smoothly and avoid costly ignition coil replacements.

Conclusion

So there you have it! Everything you need to know about ignition coils for your 2004 Infiniti G35. By understanding how ignition coils work, recognizing the symptoms of failure, and following the diagnostic and replacement steps outlined in this guide, you can keep your G35 running strong for years to come. Remember to choose quality replacement parts and perform regular maintenance to prevent future problems. Happy driving!