Doing head and cam install so I pulled the knock sensor to drain the block completely. I used a 7/8" socket and the internal part of the sensor turned justa a tad while the outer threaded part remained torqued to the block.

I then got the channel locks out and the sensor broke loose easily and came out.

My question, is my sensor now trashed since the internal part rotated just a tad, or do I need a new one?

 

Mine did that when I tried replacing it. Test it with an ohm meter and see if it is still grounding to the block (put red tip in the sensor and touch the black tip to the block). If it is, I would imagine you're ok. The values are on Shoebox's website. It should also throw a DTC43 if it's not working.

 

They are not too expensive if it was damaged. It might be a good idea to replace it anyways, while you already have the block drained, since they sometimes go bad over time.