Coolant leak on back of engine 1998 achieva?
There is an engine plug that fits in a water jacket on the back
of the engine. If the plug is out or damaged it could cause the
water to leak out of the back of the engine. You can feel around
for a hole when the engine is cool or look for the leak while the
radiator is full and the engine is running. Be careful the engine
and water will be hot. The plug can be purchased at your local auto
parts store for about 5 bucks.