After a few successful flights I went to launch for another round, this time I noticed one of the motors did not start like the rest. Once I gave it enough throttle for lift it appeared to be spinning good but as soon as I gave it enough for lift off it flipped over to that side. I did not crash it, it just appeared. However, I did crash it into the side of my house a few weeks before and noticed that one of the motor cases was bent so I replaced the case only.
When I got home, I removed the props and it appeared to be spinning fine, I then ran the motor test and the motor that I was having trouble with had a kind of grinding noise. I do not have the logs from that day since the logs were overwritten during testing.
What is the best way to check a motor?