How To Start A Car With a Broken Key in the Ignition?

It is not unusual for a car key to give way after years of use. The thin grooves cut into the blade weaken the metal, and even a small crack can be enough for the key to snap when turning the ignition. Sometimes it happens suddenly, after a moment of extra pressure, leaving part of the blade jammed inside the barrel. This can be extremely inconvenient, especially if you are far from home or in a hurry.

In this guide we will explain why forcing the car to start is rarely a good idea, what drivers of automatic and manual vehicles should know in such a situation, and why calling an auto locksmith is usually the only reliable way forward.

How To Start An Automatic Car With a Broken Key in the Ignition

Owners of automatic cars usually face greater difficulty when a key breaks in the ignition. These vehicles are fitted with a shift-lock mechanism that keeps the gear lever locked in “Park” until the ignition switch confirms that a valid key is present. This means that even if the metal fragment still turns the barrel, the car may remain stuck.

Some drivers try to twist what is left of the key to coax the ignition round. It may work in very rare cases, but it is a risky approach. A weakened key fragment can wedge itself even deeper, scoring the inside of the barrel or snapping further down. Once that happens, the ignition may have to be completely replaced, which is far more expensive than a simple extraction.

Modern automatics also rely on electronic immobilisers. Without the chip that sits in the key head, the car will not recognise the signal. Even if you manage to rotate the ignition with the broken blade, the engine may not fire at all. Forcing it can cause additional wear to the steering lock mechanism and, in some cases, damage the tumblers that control the ignition.

The sensible conclusion for automatic owners is straightforward: do not force the ignition. The chance of success is very slim, while the chance of making matters worse is high.

How To Start A Manual Car With a Broken Key in the Ignition

With a manual gearbox the temptation is stronger. Because you can move the clutch and gears without electronic safeguards, some people believe they can get away with turning what is left of the key. Technically, if enough of the blade remains and the immobiliser chip is still recognised, the car might start. But again, the risks are considerable.

When a key snaps, the broken surface is jagged and unstable. Trying to turn it under pressure can deform the inside of the barrel. Tiny metal shards may scrape off and fall into the mechanism, leading to rough ignition action or even total lock-up later on. In the worst cases, the steering lock engages and the car becomes immovable.

There are also drivers who try to bypass the ignition altogether by tampering with wiring behind the steering column. Apart from being unsafe, this can damage delicate electronics and airbags. From an insurance point of view it can also cause serious problems, as interfering with the ignition circuit is often treated in the same way as an attempted theft.

Manual vehicles therefore present the same conclusion as automatics: while it may look as though there is more room for manoeuvre, the damage done by forcing the ignition will almost always outweigh any short-term benefit.

The Cost of Forcing vs Professional Repair

From a financial perspective, attempting to start the car with a broken key nearly always proves more expensive in the long run. An ignition barrel that has been damaged through repeated twisting may need to be replaced entirely. Depending on the model, the bill for an ignition switch replacement can run into several hundred pounds. In contrast, the cost of having a locksmith extract the broken blade is usually much lower, and in many cases a new key can be cut and programmed at the same time.

If your key has snapped the ignition, the safest course of action is to stop and call for help. Do not try to drive the vehicle until the broken part has been removed.

At Phoenix Car Keys, we deal with this situation every day. Our specialists have the tools to remove broken fragments without damaging the ignition barrel and, if necessary, we can supply and programme a replacement key. We operate a doorstep service, so you don’t need to worry about moving the car or attempting risky DIY fixes. One of our ignition specialists will come directly to your location and carry out the repair on site.

For a free consultation or to book the next available appointment, phone us on 03330065210 or request a call back using the form on our website. Our service runs around the clock, so whether the problem happens first thing in the morning or late at night, help is always available.