Updated at: 25-03-2022 - By: Lucas

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What happens if I keep the ignition on for a long period of time? It all depends on what kind of vehicle you have and how frequently you do this.

When the engine is already running, there is no need to place or leave the automobile in “ignition.” If you hold the ignition for too long, you’ll need to know what happens.

We’ll cover a range of topics related to “ignition” and “starting a car” in this piece. It’s time to sit back and read.

What Happens If You Hold The Ignition Too Long?

How Long Can You Leave Ignition On-2

Ignition overheating is a real possibility.

No harm will be done if you leave your car’s ignition key in the “Start” position for a long period of time, even after the engine has started.

However, the “starting motor,” which contains a mechanical overrunning clutch that transmits torque in a single direction, is impacted by this activity.

The flywheel is spun by the engine’s starter motor, which is powered by a clutch that only allows torque to go in one way. Consequently, a “starting motor” that has been charged/provided with power to spin freely will continue to get this charge/power if the car’s ignition is left on for an extended period of time.

A gear pushes out toward the flywheel’s teeth on the outer ring when you turn your car’s key to “start.” This action causes the flywheel to spin.

As a result, the gear that shifted to the flywheel’s teeth will continue to engage after the car has been started and the key is still in “start.” This is a negative thing.

The teeth of the gear and the flywheel could be damaged if the gear continues to engage. It’s safe to say that, if you leave the ignition on for an extended period of time, you’ll hear some noise. This will cause a cracking sound.

To put it another way, if you leave the ignition on for too long, you’re putting yourself at risk for a lot of expensive harm. Your flywheel, solenoid, gear, or any other part in the starter motor bay could be damaged.

On the other hand, this action has no known negative effects on modern cars (fitted with electronic ignition and fuel injection).

Things to note and watch out for

As soon as you hear a cranking sound, turn off your automobile and then quickly turn it back on.

The price of a flywheel is exorbitant. Flywheel replacement is required if the teeth are damaged.

For a maximum of 10 seconds, most car owners’ manuals recommend leaving the key in the “start” position. Ignoring this time limit on a regular basis can lead to major consequences in the long run.


Leaving your automobile in “ignition” for an extended period of time is just as risky as leaving it unattended. What happens if you hold the ignition too long has been detailed here.

It’s not a big deal if you don’t do it all the time, but if you do, you’re putting yourself at risk for costly damages. Your car’s engine is its powerhouse, and it should be used with caution.