What Actually Causes Ignition Failure and Broken Keys
Ignitions fail for several distinct reasons, and misidentifying the cause leads to unnecessary parts replacement and expense. Worn wafers inside the cylinder are the most common culprit — over years of daily use, the small spring-loaded discs that read your key's cuts gradually wear flat, causing the cylinder to bind or turn without starting the engine. A key that was already worn, or one cut from an inaccurate duplicate, accelerates this process because it forces the wafers rather than gliding through them. Electrical faults in the ignition switch — the component behind the cylinder that actually sends power to the starter — produce symptoms that look identical to a mechanical cylinder failure, so a proper diagnosis must rule out both. Our technicians test the cylinder mechanically and verify switch continuity before recommending any repair path.
Broken keys are almost always the result of a combination of factors: a key that has developed a hairline stress fracture from repeated bending, a cylinder that was already binding and requiring extra torque, or an attempt to use the wrong key. Houston's heat cycles are genuinely brutal on metal — keys left in a hot car or repeatedly exposed to 100-degree summer temperatures can develop micro-cracks invisible to the naked eye. When the key finally snaps, the break point is often deep inside the cylinder, making extraction with household tools nearly impossible without pushing the fragment further in or scratching the internal components.