Strange one here. 03 Cooper S. When I first start driving the car, only after I start moving, I can hear what sounds like water running up in the dash. It does not do it every time, and it stops after a little bit of driving. It was still there even in the very, very cold mornings this winter. Any Ideas?

 

Sounds like it needs the air bleed out of coolant system, or you have a leak and air has gotten in. Did you change the thermostat recently ? It makes that noise going through the heater core.