Hi... i have a problem with my car related to overheating and this is what happens: bought the car a year ago, had a blown HG, replaced it (head had water passages blocked with rust), cleaned all and reassembled everything, when i bought the car it did not have a thermostat and was running only with water. Once i placed the thermostat i have the problem that the temp gauge starts to climb almost immediately after i start driving and it start to climb until it reaches the mark above the middle one (this in less then 15 minutes of driving), is i stop the car and check the water pipes, the top is hot, lower is cold and radiadtor is cold. I already replaced the water pump, placed a new thermostat (opens at 84ª), replaced the thermal switch on the radiator (starts the fans at a lower temp also), replaced the radiator, replaced the fan, replaced the expansion tank and cap and it remains the same, already its the 3rd temp sensor beeing that the last one was a original VW sensor (35£) the temperature only rises that much if i start to press the pedal, at slow cruise it passes a little of the middle,but when i press it it can go almost at the last mark before the red, If i slow down, the temperature decreases and if i stop the car and check the hoses, both are hot, no pressure in the circuit and the fan is working also. i am baffled at this... already changed everything i can think and problem still persists :( please help me