Hi. When I press gas pedal by increasing rev 3000, my car radiator upper hose start swelling. Could please help to get answer
This sounds like there may be excessive pressure building in the cooling system. A couple of things to check would be the hose, coolant fill cap, the thermostat and the actual system pressure. If the cooling system fill cap is faulty it would no longer allow pressure relief as it normally would. If the hose is soft it would be an indication that the hose is worn and needed to be replaced. Testing the cooling system pressure to make certain it is not way over the fill cap pressure limit. The normal limit would be around 17 psi. A much higher pressure would indicate cylinder compression leaking into the cooling system. Finally a sticking thermostat would cause a higher than normal pressure on the upper hose.