My 1997 disco is now on its 4th matrix, pressure tests ok, no oil /water mix, no vibration, no twisting damage on install, no water or oil loss, when heater hoses connected together, any ideas except being cold in winter.
Have you tryed to change the pressure cap for the water system. May be the cap is faulty and when the pressure gets to much its not letting go. May be you got a head gasket problem.
