What is the reason why the key can keep turning but cannot unlock?

[Tommy]

The reasons why the key can keep turning but cannot unlock include: wrong direction, rusted lock cylinder, or key issues. Wrong direction: When the mechanical key is rotated in the wrong direction, the car door will not unlock. In most cases, the rotation direction to unlock the car door is clockwise, while the opposite direction locks it. If you are unsure about the unlocking direction, you can refer to the car's user manual for guidance. Rusted lock cylinder: Most car owners use remote keys to unlock or lock the car door and rarely use mechanical keys. As a result, the lock hole may rust due to prolonged disuse. In such cases, you can try lubricating it with engine oil. If it still doesn't work, the lock cylinder may need to be replaced. Key issues: In most cases, mechanical keys do not have significant problems. If there is an issue, it is usually with a later-made duplicate key that is incomplete. Sometimes, in the early morning during winter, the mechanical key may not turn when trying to unlock the car door. This is caused by residual water from car washing entering the keyhole. When the key is inserted, the locking mechanism inside fails to pop up, preventing the key from turning. In such situations, avoid applying excessive force to turn the key, as it may cause damage or deformation, rendering the key unusable.

[DiZoey]

The key keeps turning but the door won't open? I've seen this quite a few times. After decades of driving, the most common issue with older cars is either lock cylinder wear or dust buildup. The key turns smoothly, but the internal linkage gets stuck or the spring comes loose, causing the door latch to remain unresponsive. This is especially accelerated in dusty environments or when using worn-out keys. I remember once during a trip, on a scorching hot day, the car door just wouldn't open—ended up using some lubricant spray as a quick fix. For prevention, regularly use specialized lock cylinder cleaner and avoid water-based products to prevent rust. If it happens, don’t force the key; you might damage the lock further. Best to take it to a professional locksmith ASAP to avoid getting stranded. Safety first—don’t spend too long fiddling with it on the roadside.

[OscarFitz]

The key turns but the door won't open, I think it's mainly a mechanical issue. For example, the lock rod might be deformed or the hook has come off, so turning the key doesn't move the door latch. It's not hard to check yourself—just remove the interior door panel and inspect the connections. It might just need the rod to be reset or a small part replaced. A screwdriver is all the tool you need. Also, check if the key is worn out; an old key with faded teeth won't do any good no matter how much you turn it. For prevention, use graphite powder to lubricate the lock cylinder—avoid oil-based lubricants as they attract dust and can clog the lock. After fixing, test the door several times to ensure it's reliable. Dealing with such issues early saves time and prevents travel delays. It's also good to keep some emergency tools in the car.

[AvaDella]

This is a problem I often encounter, and it's most frustrating when I can't open the car door while with my kids. It's mostly due to debris stuck in the lock slot or a failed internal spring. If the key can turn, it means it's basically matched but not triggering the latch. Don't panic; first, ensure the surroundings are safe and keep the kids away from the road. Try entering through another door or use the remote to unlock. For a simple fix, gently brush debris from the lock hole with a toothbrush. Mechanics say regular maintenance can prevent this, especially in older vehicles.