I have a 86 Bayliner with a Volvo Penta Aq 131 a. Heres my problem, and the things I have checked, Over heating, it can idle all day under any load it gets hot. I have checked, the Thermostat, and the Heat exchanger to make sure.things I find interesting, The Lower out let tube (from heat exchanger) to the Mechanical Circluating water pump is soft to the touch no pressure like with a car, Should that hose be stiff like a car radiator, I have the raw water system working very well actully I just got it where it has no leaks at all Water Flows in through the heat exchanger and out the exhaust, the exhaust manifold is not hot to the touch, is this an issue when the circulating water pump needs to be replaced or is it the heat exchanger or something else I have not of messed with yet, however if I take the hose off coolant runs from the exchanger out of the opening HELP ME PLEASE IM STUMPED