While prepping my car to start again after a rebuild I found this green screw plug that I dont know where it belongs, or if it's even to my car or something else. My timing belt broke and I had to change all the bent valves, timing related parts, and all the other issues I found while removing the cylinder head. Huge problem is that car is visibly leaking coolant from the new headgasket area which I think is just due to me not using the torque wrench correctly to get the headbolts down. But, I want to make sure it's not because of that green mystery plug and the water is just running towards that area. Going tomm to get another torque wrench .