How many coils does a 4-cylinder have?
A 4-cylinder engine typically has 4 ignition coils, one for each cylinder. The number of ignition coils in an engine corresponds to the number of cylinders, as each cylinder requires its own coil to provide the spark that ignites the air-fuel mixture and powers the engine.
Understanding Ignition Coils in 4-Cylinder Engines
The ignition system in a 4-cylinder engine is responsible for providing the timed electrical spark that ignites the air-fuel mixture in each cylinder, allowing the engine to run. This system consists of several key components, including the ignition coils, which are the focus of this article.
Each ignition coil in a 4-cylinder engine is dedicated to a single cylinder. The coil generates a high-voltage electrical pulse that is delivered to the corresponding spark plug, which then creates the spark that ignites the air-fuel mixture in that cylinder. This process occurs in a specific firing order to ensure smooth and efficient engine operation.
The Role of Ignition Coils
Ignition coils play a crucial role in the proper functioning of a 4-cylinder engine. They are responsible for transforming the low-voltage current from the battery into the high-voltage spark required to ignite the air-fuel mixture in each cylinder. Without functioning ignition coils, the engine would be unable to start or run properly.
In a 4-cylinder engine, the ignition coils are typically arranged in a specific pattern, often in a straight line or in a V-shaped configuration, to ensure optimal placement and connection to the spark plugs. The coils are typically located near the top of the engine, close to the spark plugs, to minimize the distance the high-voltage spark must travel.
Troubleshooting Ignition Coil Issues
- Symptoms of a failing ignition coil: Engine misfiring, reduced engine performance, decreased fuel efficiency, and difficulty starting the engine.
- Diagnosing ignition coil problems: Using a multimeter or other diagnostic tools to test the coil's resistance and output voltage, as well as visual inspection for signs of damage or wear.
- Replacing ignition coils: Ignition coils are typically easy to access and replace, often requiring only a few basic tools. It's important to replace all the coils at the same time to ensure consistent engine performance.
Proper maintenance and timely replacement of ignition coils are crucial for maintaining the reliable and efficient operation of a 4-cylinder engine.
How can I tell which ignition coil is bad?
You can tell which ignition coil is bad by listening for a misfire, checking your car's computer for codes, and swapping coils between cylinders to see if the misfire moves. Other methods include unplugging each coil one at a time or using a spark tester to check for a weak or absent spark.
This video demonstrates how to check for a misfire without an OBD2 scan tool: 30strackpalmerYouTube · Feb 2, 2024
Diagnostic steps
- Use an OBD2 scanner: Read the trouble codes to identify which cylinder is misfiring (e.g., P0301 for cylinder 1).
- Swap the coil: Move the coil from the misfiring cylinder to a different cylinder.
- Retest: Clear the codes and run the engine again. If the misfire code now points to the cylinder where you moved the coil, that coil is the problem.
Other tests
- Unplugging test: With the engine running, unplug the electrical connector from each coil one at a time. A healthy coil will cause the engine to change or misfire more when its connector is unplugged. If the engine's behavior doesn't change when you unplug a coil, that coil is likely bad.
- Spark test: Remove the coil and spark plug from a cylinder. Ground the end of the spark plug and hold it near the engine block. Have someone crank the engine. A good coil will produce a strong, blue spark. A weak or absent spark indicates a bad coil or wiring issue.
- Visual inspection: Look for visible damage like cracks on the coil. You can also spray a small amount of water onto the coil while the engine is running; sparks will be visible if there are cracks.
This video explains how to test a 12V ignition coil: 48sMiracleMAXYouTube · Mar 6, 2021
Common symptoms of a bad ignition coil
- Engine misfires, rough idle, or shaking
- Check Engine light is on
- Difficulty starting the engine
- Sluggish acceleration and poor fuel economy
- Engine stalling
You can watch this video to learn about primary and secondary resistance testing of an ignition coil: 1mBSK GarageYouTube · May 9, 2016
How many coil packs are in a 4 cylinder?
A 4-cylinder engine typically has four ignition coils, one for each cylinder, in a modern "coil-on-plug" system. Older vehicles might use a single "coil pack" containing two separate coils, where each coil fires two cylinders simultaneously (a "wasted spark" system).
This video shows the location of ignition coils in a car: 59sAuto Repair GuysYouTube · Aug 12, 2022
Modern "coil-on-plug" systems
- Each cylinder has its own ignition coil, mounted directly on top of the spark plug.
- Therefore, a 4-cylinder engine has four individual coils.
- If one coil fails, only that single coil needs to be replaced.
Older "wasted spark" systems
- These systems use a single component called a "coil pack" that contains two individual coils.
- Each coil in the pack is connected to two cylinders, which are known as a pair.
- For example, in a 4-cylinder engine with a firing order of 1-3-4-2, one coil might fire cylinders 1 and 4, while the other coil fires cylinders 2 and 3.
How much does it cost to replace engine coils?
Replacing engine coils costs between $200 and $300 on average for a single coil, but the total can range from approximately $130 to $450 or more, depending on the vehicle and labor. The final price is affected by the cost of the part itself, which can be $35 to over $300 per coil, and labor charges that can add up based on how difficult it is to access the coils on your specific car.
Cost breakdown
- Parts: Costs can range from as little as $35 for a simple coil to over $300 for more complex or high-performance parts.
- Labor: Hourly rates typically range from $50 to $150, and the time it takes a mechanic can vary from 30 minutes to several hours depending on the car's design and the number of coils being replaced.
Factors that influence cost
- Vehicle make and model: Older or less common vehicles may have different, more expensive coils or require more complex installation.
- Coil type: Newer cars with individual "coil-on-plug" systems have more coils than older cars with a single coil feeding a distributor.
- Labor difficulty: Some coils are easy to access near the top of the engine, while others may be located near the firewall, requiring other parts to be removed.
- Number of coils: If you need to replace more than one coil, the total cost will increase significantly.
- Shop vs. DIY: If you are comfortable with car repair, you can save on labor costs. Parts can range from $40 to over $100 for DIY jobs, while professional replacement of a full set can cost $500 to over $1,200.
Important considerations
- Related parts: It may be a good idea to replace the spark plugs at the same time, though this is not always necessary if they are in good condition.
- Potential damage: A failing ignition coil can cause serious engine misfires, which could damage other parts of the engine over time, making it important to fix it promptly.
Is there a coil for each cylinder?
Most new vehicles use a coil-on-plug design, so the ignition coil is attached to the spark plug. With this system, each cylinder has one coil pack.
