There is a large steady flow of green fluid leaking onto the ground from somewhere in the engine
My car has 175000 miles.
My car has an automatic transmission.
The most common leak for what you are describing is from the water pump. The only way to be sure is to test and see where it is coming from. I recommend having a technician, such as one from YourMechanic, come and pressure test the system to locate the leak and make any needed repairs for you.
Have a car question? Get free advice from our top-rated mechanics.