Help please, our old 1998 300 disco has just let us down.she was out on thurs day earning her keep (towing a trailer) when she started to overheat, and a rattling from the engine.turned her off straight away (steam every where)and then let her cool down.when the water was checked she took 2 pints. when we went to start her it took a bit, and water/ steam was coming from the header tank. once she had run for a short time starting was not a problem. any help please. thanks.