serious tooth crown pain

I have had a couple of crowns on the upper left side in the back that have broke on the inner side of my mouth.
There is a hole where the piece of crown was that hurts at random, if I stick my tongue in it to remove food.
The pain feels like I stuck a piece of tinfoil in it!
Also, just recently, out of nowhere, the very back of my upper left side,where the crowns are partially broken, I got some serious radiating pain.
Took some ibuprofen,seems to have calmed the pain.
What Is causing these 2 types of pain?
I thought when you had a root canal done, the nerves are removed.
So,where is this pain coming from??

[Jerome Tsang, DDS]

I would recommend going back to your dentist to get the area checked out.  If there is a root canal done on it, then yes, there probably shouldn't be any pain in the tooth itself but the gums/bones around the tooth are still alive and can be the source of pain.