Rough idle is almost always a sign of something going wrong in your car’s engine. When the idle speed is too high or too low, it can lead to all kinds of other problems like jerky acceleration, stalled starts, and maybe even overheating. An ignition switch must be doing something right if it has its own subcategory under “engine performance issues” in diagnostic tests. But what exactly? Is there any truth to the old theory that a bad ignition switch can cause rough idle? Let’s find out.
Can Bad Ignition Switch Cause Rough Idle?
Yes, a bad ignition switch can cause rough idle. Your ignition switch is responsible for starting your car and turning off your engine, and it’s essential that it’s in good working condition. A bad ignition switch can cause all sorts of problems, such as rough idle, engine stalling, or complete engine failure.
Why Does A Bad Ignition Switch Cause Rough Idle?
Check Your Battery First
One of the first things you should check before anything else when you notice a rough idle is your battery. Since a faulty Ignition Switch is an electrical problem, make sure your battery is in good health first. A battery going bad is one of the most common causes of a rough idle. If your battery isn’t in good health, it may not be able to supply the amount of power your car needs to start. So, you can replace it and see if that solves the problem. However, if your battery is in good health but is still causing your car to have a rough idle, then there are a few other things you should check.
Faulty Spark Plugs
The spark plugs of your car ignite the fuel in your engine, and they are one of the parts that have a direct impact on your car’s idle. If they aren’t working the way they should, they can cause your car to have a rough idle. If you have recently replaced your spark plugs and are still having this issue, then you should check if they are installed correctly. If they aren’t, they won’t be able to ignite the fuel properly and your car will have a rough idle. Another problem that can cause spark plugs to give you a rough idle is foul play. If your spark plugs have been damaged and are not working properly, they might be causing your car to have a rough idle.
Faulty Fuel Injectors
The fuel injectors of your car are responsible for managing the amount of fuel that enters your car’s combustion chamber. If they aren’t working properly, they can cause your car to have a rough idle. This can also be a result of some mechanical damage. For example, if your fuel injectors have been clogged, they won’t be able to deliver the right amount of fuel to your combustion chamber, causing your car to have a rough idle. If your fuel injectors are working but your car still has a rough idle, then you should check if they are installed correctly. If they aren’t, they might not be working properly and causing your car to have a rough idle.
Faulty Oxygen Sensor
The oxygen sensor of your car measures the amount of oxygen in your exhaust. The engine of your car uses that data to make sure that everything is running smoothly; for example, it helps to regulate the timing of your car’s spark plugs. If the oxygen sensor isn’t working properly, it can cause your car to have a rough idle. This could also be a result of some mechanical damage. For example, if your oxygen sensor is clogged, it won’t be able to read the data correctly, and your car will have a rough idle. If your oxygen sensor is working but your car still has a rough idle, then you should check if it is installed correctly. If it isn’t installed correctly, it won’t be able to read the data correctly and will cause your car to have a rough idle.
Carbon Build-Up On Your Car’s Valves And Combustion Chamber
The valves and the combustion chamber of your car are responsible for regulating the amount of air and fuel that enters the engine. If there is carbon build-up on them, it can cause your car to have a rough idle. If your car has a rough idle and you have already checked all the above problems and you haven’t been able to find the reason for it, then this could be the problem. You can get your car’s valves and combustion chamber cleaning. But be careful because if they have become too cluttered with carbon, they will have to be replaced.
How To Fix A Bad Ignition Switch?
Install A New Switch
If the ignition switch itself is faulty, you won’t be able to repair it. Instead, consider installing a new switch. Depending on the model of your car, you may be able to find a replacement switch at a local auto parts store. However, you can also order a new ignition switch online. Depending on the part and supplier, the cost of a new ignition switch can range from $15-$100. To install a new switch, you’ll need to open the dashboard and identify the wires that lead to the ignition switch. Then, use a wiring diagram and follow the instructions included with the replacement switch.
Clean The Contact Points
Over time, the metal contacts inside the ignition switch can become corroded and dirty. This can cause a bad connection and lead to a faulty ignition switch. To clean the contacts inside the ignition switch, you’ll need to open the dashboard of your car. Once you’ve removed the dashboard, you should be able to see the switch. Use a small screwdriver to remove the switch and clean the contacts with sandpaper. Depending on the specific model and make of your car, you may need to remove the cover of the ignition switch to access the contacts. In this case, you’ll want to clean the cover and the contacts beneath it. Once the contacts are clean, reassemble the switch and test the ignition. If it still doesn’t work, proceed to the next solution.
Add Graphite Lubricant
If the contacts of the ignition switch are clean and in good condition, you may want to add a small amount of graphite lubricant to the switch. To do this, remove the switch from the dashboard and add a small amount of graphite lubricant to the moving parts inside the switch. Be careful not to add too much, as too much lubricant can cause the switch to overheat and wear out faster. Once the switch has been reassembled, start the engine and test the ignition. If it is still faulty, proceed to the next solution.
Replace The Contact Springs
If the contacts inside the ignition switch are clean but the springs inside the switch are broken, you may want to replace the springs. To do this, remove the switch from the dashboard and identify the springs inside the switch. They are usually small pieces of metal with one end bent over. Depending on the model of your car and the specific make of the switch, there may be one or more springs inside the switch. To replace the springs, use a small screwdriver to pry open the switch. Once you’ve identified the broken springs, remove them and replace them with new springs. Once you’ve reassembled the switch and reinstalled it in the dashboard, test the ignition. If it is still faulty, proceed to the next solution.
Replace The Contact Points
If the springs inside the switch have broken and the contacts are still corroded, you may want to replace the entire switch. To do this, remove the old switch from the dashboard and replace it with a new one. Depending on the model of your car, you may be able to find a replacement switch at a local auto parts store. However, you can also order a new ignition switch online. Depending on the part and supplier, the cost of a new ignition switch can range from $15-$100. To install a new switch, you’ll need to open the dashboard and identify the wires that lead to the ignition switch. Then, use a wiring diagram and follow the instructions included with the replacement switch.
Try A New Battery
If none of the solutions above have worked, your ignition switch may simply be worn out. To test this theory, you can try a new battery. To do this, start by disconnecting the battery and waiting 30 minutes. Then, reconnect the battery and test the ignition. If it now works, the switch is faulty and you can proceed to the next solution. If the ignition still doesn’t work, the problem is likely a bad switch. In this case, you can proceed to the next solution.
Summary
The ignition switch has a lot of functions, but its most important one is controlling the timing of your engine’s cylinders. If the timing is off, your engine will run rough and idle roughly. If the ignition switch is faulty, it might cause other issues as well – like stalling at idle. If you notice a rough idle in your car, have your mechanic check the ignition switch as soon as possible.
