Mitsubishi Repair: water noise behind the dash, mitsubishi magna, coolant system

Question
G/day I have a Mitsubishi magna 1996 auto when starting an warming up while revving  there is a water noise behind the dash sounds as if its trying to fill up or something which the car is having a heating problem any help would be appreciated.

Answer
Wayne,
It sounds as if you have  clog in your heater core or coolant system.  There are two water hoses that go from your water pump into your heater core.  The heater core located behind your dash (behind the glove box).  The problem you're describing sounds evident as the little of the coolant is getting to the heater core; which would explain your heating problem.  Have your heater hoses inspected.  You may just have a blockage in one of them.
Good luck!