without knowing year make and model i am going to go out on limb and say check your waterpump. start the car without the radiator cap on and wait for the temp to come up, if the water gets hot right away and doesnt seem to be circulating through the radiator the water pump is no longer working.
someone mentioned a head gasket but you can easily check this without tearing into it. with the engine cold (preferably in the morning) pull the dipstick and look to see it there is any coolant on the stick. remember not to wipe it as soon as you pull it otherwise you will get a false reading.Soon as I start my car it gets hot i change the thermostat and still hot whats the problem?head gasket needs to be changedSoon as I start my car it gets hot i change the thermostat and still hot whats the problem?have you checked water levels ?Soon as I start my car it gets hot i change the thermostat and still hot whats the problem?Does it REALLY get hot, or is it just indicating it is? Do you see steam, hear boiling water?
Chances are it isn't really getting hot, and all you have is a bad sensor that needs to be changed out.Soon as I start my car it gets hot i change the thermostat and still hot whats the problem?By as soon as you start the car do you mean immediatly? If so then it could be your temp sensor has gone bad. If it takes a min then starts to verheat I would check the coolant level, If that is good try flushing the coolant.Soon as I start my car it gets hot i change the thermostat and still hot whats the problem?when it gets hot, do you get any heat in the car? like through the vents or defroster? You could have a bad waterpump or be as simple as low coolant. even if it seems up, some cars have a hell of a problem bleeding the air out of the system. if there is a bubble and won't circulate the coolant. hope this helps you.Soon as I start my car it gets hot i change the thermostat and still hot whats the problem?check your radiatorSoon as I start my car it gets hot i change the thermostat and still hot whats the problem?Before ANYONE can answer this properlly. What year make and model do you have. This little bit of info can help alot.Soon as I start my car it gets hot i change the thermostat and still hot whats the problem?Your car will overheat if:
-Thermostat is stuck open
-If the fan is not working
-If it's got an electric fan there may be a problem with the relay or the thermo swtich or the fan itself. YOu can connect the fan directly to the battery to make sure it's working
-If not an electric fan the problem may be the fan clutch
-The hoses could be soft and compressing blocking the flow of antifreeze
-You could have a leak somewhere.
Your head gasket may be blown, this can be verified by doing a compression test, inspecting the oil for the presence of coolant or inspecting the coolant for the presence of oil
