Yes, you need to fix it NOW!!
Seals that leak.
Failed brake line.
No. Hydrogen does not leak through glass.
Cooling system leak or engine overheating and steam escaping from the radiator cap.Cooling system leak or engine overheating and steam escaping from the radiator cap.
Leaks can be hard to find. Turn a water hose toward the vehicle while some one is inside. Spray around the doors windows and the windshield and back glass. The leak should be visible and then it can be determined how to repair it.
Increase the gland steam pressure if air is leaking in. If gland steam is leaking out, replace the seals. If the leak is in the casing, repair or replace the damaged parts.
possibly a weld if leak is accessable and repair cheaper than replacement where leak occurred
only if there is a hole in it
If there really is no leak then it is likely a head gasket allowing coolant to leak into the cylinder and go out the exhaust as steam.
Leak in heater core. Replace core.
You have a leak that needs repaired.
Smoke: A engine oil or tranny fluid or lower steering fluid LEAK. Steam: A water leak.