The distributor cap doesn’t sound like such a vital part, but it is integral to the working of your car’s engine. If the distributor cap is faulty then the ignition sequence inside your engine will be out of proper working order. Here are a few signs that your distributor cap needs to be changed.
If you’re idling at a stop sign or red light and your vehicle seems to be shaking more than normal that could be a sign that the rotor inside the distributor cap is not spinning normally, and therefore the timing to start the firing process correctly is off.
STARTING IN THE COLD
If you live in a cold weather area, unfortunately your distributor cap will be more prone to break than if you live in warm weather. This is because the cap is covered in plastic and when it goes from cold to hot instantaneously, it can crack and break. If you observe that your car has trouble starting on a regular basis, check the distributor cap for cracks. If you see one, you need to have the cap changed. Even if there aren’t cracks in the cap, there may be corrosive materials on the inside of the cap, which would also render it ineffective.
STALLING AND BACKFIRING
If your vehicle starts okay but acts up once you’re on the road, stalling and/or backfiring, this could be because your distributor cap has an issue. Since the cap contains the rotor that spins to help the voltage move from the coil to the spark plugs, if it is cracked, clogged with oil, or anything else that stops it from spinning or slows the spinning down, it will only work part of the time.
If you observe that your revolutions per minute are all over the place, it could be because the connection between the distributor cap and the distributor wires has gone south. Again, check the cap for cracks or evidence of burning, singeing, or corrosion.
If you turn your engine on and everything seems to be working, but you can hear a high-pitched squealing noise, turn your car off and remove the distributor cap. There may not be any visible signs of wear and tear immediately, but check the underside where the coil sits. You may be surprised at just how much muck has accumulated under the cap. change the cap with a new one and that should correct the issue. If you still hear that sound, though, you may need a whole new distributor.
TROUBLE TURNING OVER
Sometimes people observe that along with their car stalling, their vehicle seems to turn over some times and not others. You will probably realize that it will turn over when the engine is cold, but not when it is hot. This can definitely mean that there is something wrong with the distributor cap, so have it checked out. If the cap seems fine, it might be another part in the distributor that is throwing off the ignition sequence.