wheres my coolant going?

[macc]

I noticed my resevior was empty so I filled it up (yes after the car sat all night) I drove 12 miles and it was empty again. Filled it up and drove and now empty again. I have put a piece of cardboard under the car each time and no drips on it. no anti-freeze in the oil or tranny. It's not leaking out when parked, just when it's driven and it's driving me batty. Can anyone tell me where it's going? thanks

 

[83 markvi]

Check for leaks. Pressure test. Could be radiator cap. Could be at hose clapnp. Could be heater core. Look for wet passenger floorboard. There is hose under manifold. Look for leak out back engine.

 

[slowmkviii]

Good chance on it being the hose in the valley.
Look for any coolant remnants on the motor.
Sometimes when a water pump is going it will only leak when driving too.