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How to Replace an Ignition Coil

Deeptee A
Although substituting an old ignition coil with a new one is the work of a professional, it can also be done by an amateur. All you need to do is strictly follow the instructions mentioned here.
An induction coil, also called spark coil, converts low voltage from a car battery into a high-voltage that is required by spark plugs to ignite the spark which in turn starts the vehicle. It is an essential part of the ignition module in the car battery.
When this coil is subjected to everyday wear and tear, it tends to misfire and cause fuel wastage and you may not be able to start your car. Hence, its timely replacement is extremely necessary.
In simple words, an ignition coil is an electric transformer, which assists in transferring the electric current from the car battery to the spark plugs to help the car to start. Depending on the model of the automobile, you may have one coil in your engine.


Replacing an ignition coil is the job of a professional. If you want to attempt this job and are doing so for the first time, then it is advisable to let the mechanic handle it for you. Car repairs are not easy and doable at home. If anything goes wrong, you may end up with worse problems. Also, the cost of sorting out this mess will be more.
But if you find yourself in a position to undertake the task yourself, please follow these instructions.

1.The first and the most important point is to locate the negative battery cable in the car engine and disconnect it to avoid receiving an electric shock.
2. Locate the coil that needs to be replaced. Look through the engine very carefully or you might end up changing the one that is in a perfectly good condition.
3. Once it is located, the next step is to unplug the connecting electrical connector. After the electrical connector is unplugged, disconnect the spark plug wires. Remember to label the wires before disconnecting them, so that you will be able to reconnect correctly once the task is done.
4. The next step is to remove the old ignition wire. For this, you will need to loosen the retainer bolts and then remove the coil slowly from the valve cover.

5. Compare it with the new one to ensure that old coil is being replaced with the correct coil.
6. Insert the new coil in the valve cover correctly and delicately. Ensure that you do not damage it while you do it.

7. Reinstall the valve in the retainer and bolt it up securely.
8. Once the retainer is bolted properly, reconnect the spark plug wires and the electrical connector. As these wires were labeled before disconnecting, reconnecting the same should not be a problem for you. It is vital that all the wires are connected to the right plugs to avoid complications.
9. The final step is the reconnection of the negative battery. Start the car to check if it fires up. You will know that your job was successful when the engine roars.
These instructions should be sufficient for the replacement. The most important thing to remember here is that this is a challenging task, that needs to be undertaken only by those who are able to understand the working of automobiles. If you are trying this for the first time, then consult an expert.

Replacement Cost

Like all other car parts, replacing ignition coil is a moderately expensive affair. These coils can also be bought cheap online, but it is strongly advised not to do so. You deprive yourself the opportunity to check the coil thoroughly when you buy it online.
You can always check the coil in shops selling auto parts, before purchasing it. If you buy directly from the dealership where you purchased your car, they might charge you more but will guarantee the quality of the product.
Don't be tempted to buy cheaper varieties. It is essential to replace the damaged coil to eliminate the risk of engine failure and ensure smooth functioning of the engine. Be smart and invest in a good coil.
It is always better to leave technical stuff to the respective experts. Do not attempt to replace ignition coil on your own unless you have some expertise and knowledge in that area. Get it done by a mechanic to ensure good engine performance.