well it seems all is not ok with the rangey.had it out today with a trailer on the back weighing 1300kg and as soon as i got going over 50mph it boiled its water up and cut out, left to cool topped water back up and got going again, soon as i got upto speed again it boiled water up again so again i let engine cool down and topped water back up. rest of journey was 30-40mph roads and when i got to my destination it hadn't used any water.did the same roads home with trailer on but stuck 40mph and again didn't use a drop of water
what can the problem be????