I have a 1999 Tahoe. My driverside doorlock is frozen or something. I try to stick my key in the hole but it doesn't fit all the way in and i can't turn it. When i heat up the key and stick it in it works just fine. If you guys could come up with any suggestions for getting rid of this problem i would appreciate it. Thanks

 

try puting some graphite in the key cylinder.

 

small amount of anti-freeze in the lock. It lubricates and won't freeze.