Ran into this while doing an oil change, why is this like this? Why is there a chunk of thread missing? Vehicle is a 2019 Buick Cascada. Based on the look of things, At one point before it came to me the threads got cross-threaded or stripped, there was an attempt to retap and rethread the hole. There was a HeliCoil installed, And it came out while I was removing the drain plug.
I don’t know, but if I give a wrong answer, you should get a better right answer from someone else.
I googled it and this is what I found:
IANAM, but it took one glance at the photo to know why there was a drainage route through the threading: um, drainage.