How to Replace a Car’s Spark Plug Cables

It is not really difficult to change spark plugs; it is usually done without using any tools. Every spark plug wire is connected with a spark plug, it brings and electric spark to the spark plug for igniting the fuel present in the cylinders of the engine. A spark plug that is damaged will make the car run in a rough manner besides affecting its gas mileage. The only things needed to replace spark plug wires are getting new ones. Here are simple steps.


Step 1:

First, the bonnet has to be opened and the spark plug wires have to be located. They can be red, black, orange or blue in color. However most of them are black. Most often, the number of spark plug wires match with the number of engine’s cylinders.

Spark Plug Cables

Step 2:

Now, open the box containing the new spark plug wires. In case the new wires are not labeled then it’s appropriate to lay them out according to their length.

Step 3:

Start from one end of the engine and only the first spark plug wire should be removed. Now the boot present at the end of the plug wire should be pulled until it comes off.

Step 4:

The wire has to be followed to the other end where it is plugged to the distributor cap. Pull on the end of the wire to remove it from the distributor cap.

Step 5:

Inspect the spark plug for its quality. A spark plug of a fine quality will be lightly coated with deposits of grayish brown in color. In case of presence of heavy deposits, if the electrode or core nose is damaged or if the spark plug is black, then it is better replace the spark plug.

Step 6:

It is essential to note that many cars have small plastic pieces with slots; these slots are meant for holding the wires in their proper place so that they will not rub against each other or rest on any part of the engine. Make sure that you put the spark plug wires back into their slots for ensuring a better and longer life.

Step 7:

Now, the old spark plug wire can be replaced with the new one of the same number or length. The plug wire makes a little pop as it snaps on the spark plug.

Step 8:

Continue the same process for the next spark plug wire. Only one has to be taken off at a time and replace with the new one till all the wires have been replaced.

Spark Plug Cables

Tips and Precautions

  • Replacing spark plug wires should be part of a 30000 miles tune-up, many auto dealer shops don’t include this because the cost of spark plug wires increases the cost of tune-up.
  • Only remove and replace one spark plug wire at a time.
  • Use a high-quality brand because cheap spark plug wires are definitely not worth your savings.
  • A number of cars have spark plug wires permanently attached to the distributor cap. This case requires you to buy and replace the wires and cap simultaneously.
  • All the spark plug wires should not be taken off at once even if they are numbered. In case the wires are not and needs only replacing, then only the wire can be purchased without buying the complete set.
  • The spark plug wires must go back to the distributor cap in exactly the same order in which they came off. If the order is changed, the car may run badly or may not even run. There can be a serious damage if the order of the plug wires is switched,