Hmmm.... So you did not take the lock out, actually? This is a strange way of getting to lock, but I understand why you had to, as cylinder will not turn with key in it.
I assume, this is answer to your puzzle:
the spare key works,
but the most-used key (quite worn) works rarely... only after playing with it for a while.

Quite worn is likely to be the key, pun intended. If your key is like mine, you have double edged key with groves on them.



And if you have worn out key, pins will be in slightly wrong places, and might as well jam the cylinder in lock housing. Your key should have two of rows of pins, as shown in pic 1.

 

I have a 99 and had to replace the tumbler barrel once. Fortunately I had a friend who was a GM service manager who helped. It was quite to ordeal, and what I remember most was there was a special tool you HAD to have to remove something in the steering column to have access to the tumbler.

 

Another update, people...

Yes, Ukrkoz, that is the type of key that I have here.
After some time, I was able to slide the cylinder out.
The cylinder sometimes acts as it should, sometimes not.
Sometimes, it won't turn all the way to "start".
I think something inside the cylinder is messed up.

Time fer a new cylinder, me thinks.
Unfortunately, that means different keys for the ignition and the doors. Ah, well...

Mr. Cotton,... by chance, are you referring to this "special tool"?...



I made that from a piece of pipe,
to press on the metal part that's in front of the (A) white plastic wheel,
in order to remove the spring clip that holds it all on the shaft.
Quite proud of myself for coming up with that.

Back on earth, now,... anybody know where that extra little plastic piece goes?

Thanks.

 

I have a slight key problem with my 99 Silverado. I have to push the key down to get the ignition to turn. It works every time this way and I suppose in the future I'll have to change it but for now it works.

 

How do you post a question on this site?

 

The ignition key on my Chevy Aveo will not turn. Should I call a locksmith or tow it to the dealer?

 

actriz45,

Sorry to hear about this. Have you had the opportunity to speak to the dealership about this? If you need any assistance setting up an appointment, we'd be happy to do so.

Amber N.
Chevrolet Customer Care

 

I followed this thread for ideas on my issue.... Key just wouldn't turn in my 2011 LT.......

I went and got new my unused spare key and it didn't work at first...... I got some graphite dust and slowly inserted key in and out and lightly rocked the barrel with the key up and down while turning.

There was a slight click and it all came good....... I turned ignition on off 5 times and had no issue, but then removed the key to try again and it locked up again.


I did same thing and it's been ok last few attempts .....but there must be something on the way out in the barrel.

I appreciate people posting all their ideas - thanks guys.

 

I have a 2003 Sierra and had the same problem. Key would insert but not turn. Based on the original poster's list of things he heard to try, I used a hammer (a screwdriver handle, actually) and tapped the end of the key repeatedly while trying to turn it and low and behold, it turned! (Thank God) At that point, I disconnected the battery and removed the cylinder. The pinhole button was challenging and I had to fiddle with it for awhile before it let go, but the cylinder finally came out and I was able to replace it with an AC Delco one I had bought from Rock Auto. That one slid right in, I reconnected the battery, and the ignition worked perfectly again. Thanks to all who posted above for the help with this. It motivated me to create an account and share my experience as well.

 

I have had luck when I put foot on break!
Good luck!