I just changed my radiator,thermostate.But it is still overheating.I don't see any smokes,but the gauge for the temperature above normal.What should I do?

do a compression test to check for head gasket or cracked head
to get closer to a solution a description of the conditions and driving is necessary

Hi veronica im pierre if its still overheating and smoking you probably got a head gasket problem prestone goes in the engine and burn smell like burn candy sorry

The fans are normally thermostatic - which means they only operate above a certain air temperature. If the air coming across the radiator is below a pre-determined temperature, they will not operate.
If the temperature gauge was only half way they may not have reached the required temperature to turn on.
When you are travelling the movement of the car usually provides enough air across the radiator to keep it cool enough - when you stop and they is no moving air, the fans will normally come on then.

Double check the thermostat and make sure the water pump is doing its job. To check the thermostat, simply take it out and reassemble the housing with out the unit. Run the engine and hopefully it will get warm to hot. If not check the pump.

BLEED AIR FROM SYSTEM.....OR REPLACE WATER PUMP

The radiator cap regulates the water pressure inside the radiator. The reason the cap has various spring ratings is because the water is typically hotter than boiling point to match the requirement of the engine. Most engines operate best at above 100 degrees C, and this is why the water needs to be pressurized. Each engine's optimal temperature range may differ slightly from model to model, but most are fitted with a temperature gauge to allow the driver to judge for themselves if the vehicle is overheating.If your vehicle is operating above normal, then please check the following:
1) Radiator cap for fit and corrosion.2) Condition of radiator. Feel from top to bottom after running. If cold in one area, then this could indicate a blockage. (replace radiator)3) Remove and check thermostat. Place in a glass of hot water, and view its operation (should open). Place in cold glass of water and view (should close).4) Operation of radiator cooling fan.5) Addition of antifreeze. Antifreeze helps even out hot temperature within the engine and improves performance and running.6) Pressurize system and check for leaks.
If none of the above are issues, then remove temperature sensor and compare resistance to a new one at the same temperature. Replace if necessary.

First confirm that the engine IS actually overheating - steam, no heat to the interior etc. Sometimes a temperature sensor will fail and give a misleading 'overheat' reading on gauge. For that matter sometimes the gauge can fail and give the same misleading reading. Check that the cooling fan comes on when the engine temperature starts to rise above 'normal'. If not check (in order) fan fuse, fan relay, fan sensor, fan. Real overheating is caused by a lack of coolant AND/OR lack of coolant flow. Modern cooling systems are 'closed'. In other words there should be little or no loss of coolant. If the level is significantly low you have a leak....either external or internal. With the coolant topped up to the correct level and the radiator cap on, run the engine and look for visible leaks...hoses, valves, radiator etc. Internal leaks, eg. head gasket will usually be accompanied by white exhaust smoke (steam), hard starting, rough running and bubbles in the expansion tank. Sometimes, though NOT always, you will find the engine oil has a milky look and/or engine oil will be mixed in with the coolant.

There's nothing wrong with the overflow bottle filling with coolant, that's what it's there for. As long as it doesn't pour out the top it's fine.

sounds like you need to replace the thermostat.

change the thermostate and gasket after you change it let the truck heat up then cool then refill the radiator again after the thermostate opens do not open the radiaator with the truck hot or the upper hose hard