How to Inspect the Distributor Cap in a Car

You think there might be something wrong with the distributor cap in your car. Knowing what to look for when you have problems with the distributor cap just requires a little bit of knowledge and some careful observation. Here's how to inspect the distributor cap in your car so you can keep your ignition system running on all cylinders.

Instructions

1

Take off the spark plug wires from the distributor cap. Note the placement of these wires on the distributor cap so you can replace them in the proper order.

2

Remove your distributor cap and rotor. Most rotors will pop off, but some will have a bolt that you'll need to remove before you are able to inspect the rotor.

3

Look for carbon tracking on both the rotor and distributor cap, which shows that you've got an increase in resistance somewhere in the car's ignition system, such as a worn out spark plug or damaged spark plug wire.

4

Examine the distributor cap for cracks or wear in the plastic of the distributor cap on the inside near the contacts and elsewhere. Check the rotor for excessive wear as well.

5

Check the spring loaded contact button in the center of the distributor cap that drives the rotor. It should move freely and not be seized. If it is, replace the distributor cap and rotor with a new one from the auto parts store.