the key or the lock?

[mechamunch]

I've got a 2002 Chevy Prizm and the last owner really beat the crap out of it. It's got a number of problems, but the most vexing is that the transmission lock is flaky. Here's the scenerio:

Occasionally, I place my key in the lock and it just won't turn. That simple. I have to pound the lock a couple times just to jiggle something loose. Yeah, I don't feel too comfortable about that. Then I slip the key in, suddenly it turns. Whee.

But the bigger problem is when I try to turn OFF my car. About once a month, I can't turn my key passed "accessories." And yes, my car is in park. So, as my battery runs itself into sweet oblivion, I'm stuck on the street trying to coerce my key into letting the car take a nap. Finally, I just got into the habit of unhooking the battery whenever this happens. On its own, it seems to go back to normal overnight.

The final weirdness is this: when everything is working fine and dandy, I can turn my car on and TAKE MY KEY OUT OF THE LOCK. Which, honestly, is handy for running upstairs if i forgot something. But really puzzling. I found out I could do that from driving on a super-bumpy road. The vibrations just rattled the sucker right out. I almost had a heart attack.

I'm not what you would call very car-literate, so I can't really determine what's going on here. And I'm also just this side of the poverty line. I just need to know if it is the key or the lock. What does it sound like?

[MagicRat]

Wear on ignition locks can do a number of funny things.

I can remove the key when running on a couple of my cars due to wear. But other cars I own, with the same design of lock will not do this.

A few years ago, I read that the #2 cause of ignition lock failure is use of too-heavy key rings.
(#1 is theft).
People insist on having 10 lbs. of keys, good-luck charms and dog-chew toys swinging from the ignition key, which wears it out. If you have anything else on your keychain, try removing them and just use the ignition key on its own.

Next, does your key have nice, sharp teeth, or does it look old and worn? Worn keys can often produce trouble like yours.
If it's worn, you can go to the dealer and have them make a new key using the key-code reference numbers. A decent dealer guy can get the codes off the old key, even when worn.
This will give you a key just like it was when new. If you have the original key-codes (printed on the key knock-out plate, if you have that) all the better. If you know the dealer that sold the car when new, they may have the original key codes still on file.

BTW do not bother with the typical key-copy machine - the one that uses the old key as a pattern. That will just get you a brand-new worn out key

If a new key will not solve your problems or is impossible to get, contact a locksmith to install a new lock cylinder and key (approx. $100)

[io88]

I have a similar problem -
When I drive the car, usually no problem. When my daughter drives it, the cylinder is nearly locked - pretty much every time.

On this and other cars, I've had to jiggle or slightly rotate the steering wheel left and right lightly while turning the key, things will line up and it will turn like normal.

So far, it has worked every time ...

Also, my key does not work on the passenger door, but the power locks do. I think the previous owner replaced the door or the lock.

[mechamunch]

Originally Posted by MagicRat

Wear on ignition locks can do a number of funny things.

I can remove the key when running on a couple of my cars due to wear. But other cars I own, with the same design of lock will not do this.

A few years ago, I read that the #2 cause of ignition lock failure is use of too-heavy key rings.
(#1 is theft).
People insist on having 10 lbs. of keys, good-luck charms and dog-chew toys swinging from the ignition key, which wears it out. If you have anything else on your keychain, try removing them and just use the ignition key on its own.

Next, does your key have nice, sharp teeth, or does it look old and worn? Worn keys can often produce trouble like yours.
If it's worn, you can go to the dealer and have them make a new key using the key-code reference numbers. A decent dealer guy can get the codes off the old key, even when worn.
This will give you a key just like it was when new. If you have the original key-codes (printed on the key knock-out plate, if you have that) all the better. If you know the dealer that sold the car when new, they may have the original key codes still on file.

BTW do not bother with the typical key-copy machine - the one that uses the old key as a pattern. That will just get you a brand-new worn out key

If a new key will not solve your problems or is impossible to get, contact a locksmith to install a new lock cylinder and key (approx. $100)

Yeah, the key is worn. As for my key chain, it's got the house, the 2 car keys, the key to my parents house and two of those supermarket discount club cards. That's it. I'm sure I'm not stressing the lock.

I have no idea where it was originally purchased from, so I'm going to have to go the dealership route. I didn't know about the key-copy machine just giving me another worn-out key scenerio. Thank you, very helpful information!