If the top hose is hot and bottom hose is cold, it seems like there could be either an air lock and/or the water is not circulating. One thing to try is remove the thermostat and starting the engine afterwards you should see the water moving in the top of the rad when you rev the engine. Is the water pump actually turning I once looked at an engine that ran but got hot virtually straight away, turned out the fan belt was so loose it was slipping as the actual water pump was seized solid ! Very unlikely I know but it did happen, the fan belt finally failed. :red: To get rid of air locks try slackening the hose clips and bleeding the air out of each one then retightening the clips. The rad could be blocked so try back flushing it by running a hose through it the opposite way to normal flow, keep the hose running until the water is running clear, again this is easier done without the thermostat in place. Using an air line blow out the rad matrix from the inside out ie. opposite to normal air flow. The impellers in water pumps can gradually break up and so will then not shift the volume of water they should. All in all it is a question of working your way through things the clue is probably the hoses being different temperatures this does point to a circulation problem so thermostat, air locks, pump are all worth checking. Good luck.