leaking on 1998 Chevrolet Lumina

i replaced the thermostat and water pump (was running HOT)but now the temp is correct but it is leaking fluid, i think antifreeze, from the back of the engine, what could be causing this and do you think it could be an easy fix that i could do. someone mentioned an engine plug? what's that?

Asked by for the 1998 Chevrolet Lumina
Someone probably told you a freeze plug or engine block plug. These are usually pressed into holes in the block and prevent coolant leaks from the block. They can corrode over time and create a coolant leak. You'll really need to look with a flashlight for the source of the leak. Is it really leaking (you're losing coolant from the reservoir)? Could it be residual from your repair? Follow the wet coolant as high as you can and look very carefully. It can run along seams and ridges and look like it's coming from somewhere else.