Did a bit of Googling and found a pretty "primitive" solution, not sure if you would want to do it, but in case you are stranded somewhere maybe you can give it a go. Use a hard object, a mallet, or in my case, a metal rod, and with the key inserted into the ignition, give the key a few (fairly hard) taps inward, driving the key into the steering column. I tapped my key a few times, re-inserted the key and voila! Turns like nothing had ever gone wrong. Supposedly, the taps (although violent) will cause the lock tumblers to fall back properly. A quick but probably temporary solution. Best to get the tumblers looked into whenever possible.
E36: Ignition key cannot turn
Did a bit of Googling and found a pretty "primitive" solution, not sure if you would want to do it, but in case you are stranded somewhere maybe you can give it a go. Use a hard object, a mallet, or in my case, a metal rod, and with the key inserted into the ignition, give the key a few (fairly hard) taps inward, driving the key into the steering column. I tapped my key a few times, re-inserted the key and voila! Turns like nothing had ever gone wrong. Supposedly, the taps (although violent) will cause the lock tumblers to fall back properly. A quick but probably temporary solution. Best to get the tumblers looked into whenever possible.