Re: If it is the bypass tube it usually..............
Im losing about 8oz per tank of fuel so theres no highly obvious source of leak. Having replaced three head gaskets, hoses, crossover pipe, O rings,coolant pump and two expansion tanks in numerous visits to the dealer you'd I'd be expert in 745 coolant faults but there seems to be no end to it.
I was hoping for a miracle cure by adding a little radweld maybe to cure an inaccessible pipe fault. If it woudn't compromise the system it might buy a little quiet enjoyment of what is despite all its faults a magnificent car.