Misbehaving Door Key-Lock

The passenger door key-lock on my Corolla is stuck, so the only way I can open that door is to unlock it from the inside. It had been sticking and hard to get it to work using the key in the lock for a while, but now it won’t work at all. I opened the door panel and lubed everything that looked like it needs to be lubed, but that had no effect. The thing you pull to open/lock the door from the inside works a little smoother, and the inside handle that opens the door from the inside works smoother now so that’s something at least. But opening a locked door from the outside with a key remains a no-go.

I tried spraying some WD 40 in there, and putting some WD 40 on the key and trying to unstick it that way, but the key-lock remains stuck in the upright position, won’t budge at all by twisting/jiggling the key.

Anyone here have any luck unsticking a door key-lock ? Heat? Hammer? Ice? Different kind of lube? Cleanser? Swearing? … lol … Or is the only solution to replace the key-lock with a new one?

Guesses Welcome!!!

I use graphite lock lube to spray into sticky cylinders but sounds like you have a problem lube probably isn’t going to fix . I recently had to replace an ignition switch because it took an excessive amount of jiggling to get the key to turn .

Try Something Like PB Blaster Penetrating Spray.
CSA

I can’t help with your current situation, but I know that graphite is preferred over WD-40 in a lock cylinder. The WD-40 supposedly can gum up over time. If you do use graphite, it’ll get on your key and then your clothing at first, so be careful about that.

@GeorgeSanJose
George, Have You Got A Different Key To Try?

I’m wondering if the key/tumblers wear gradually wearing down over time.

Also, once I had a trunk lock that quit working (but, it was used infrequently). Soaking it with BP and working the key in it finally broke it loose. When I could get a look at it I saw it was corroded.
CSA

Before any lube I would put in the key and play a hair dryer on it for a while. Are you are having below freezing temperatures?

Check the lock rods inside the door panel. It sounds to me like the lock rod from the key cylinder could be binding. The rods are basically just clipped to each other with little plastic bits, and sometimes they break or slip out of position and cause issues like this.

Detach the lock rod from the key cylinder and try to move it back and forth. If you can’t, or it feels like you’re about to break something if you keep trying, then it’s binding somewhere. Follow the lock rod downstream and find the part that’s broken or out of place.

If it moves easily when disconnected from the key cylinder, then the cylinder itself is binding. You might end up having to replace it if you can’t get it unstuck.

My daughter had the same problem with her 2003 Corolla. The lock seems to be sensitive to worn out keys, and I means keys with ever so slight wear. In her case, she had to go to the dealer and get a new key cut from the VIN number. It may reach a point where you have to take the lock cylinder to a locksmith and get new tumblers put it.

Edit, if you still have the valet key and haven’t used it much, try it first. If it doesn’t work, then you may need a new cylinder or new tumblers installed in the cylinder.

@GeorgeSanJose lives in…San Jose, CA. No freezing temps there. I think the simplest thing is to try the penetrating fluid first. My preference is dry lube like graphite, but it sounds like that would be ineffective at this point. If that doesn’t work, pull the door card and inspect the mechanism. These don’t cost much. Start with the cheap fixes and then work up to expensive things like replacing the lock cylinder.

Good ideas all, I’ve give them a try and report back.

I’ve always had excellent luck with silicone lube, the trick being to get the tiny plastic straw in behind the little metal protective “shutter” in the keyhole.

Keith made an excellent point too. I always try to keep one fresh-cut key as a “master”. The good news is that this works even using a blank without a chip in it, just for use as a physical “master”. Keeps the cost down. I’ve even found that my unchipped key works to start the car as long as a chipped keyhead is held next to it when it’s used.