I have a 2002 Chevy tracker. It's been running hot on the temp gage. So, I have changed the thermostat and replaced the radiator hose because of corrosion but it still overheats and when I turn on

Check that you are getting fluid flowing through the system. Obviously make sure system is full. Check the return hose (from engine to radiator; usually the upper) is firm when hot and running and input hose (from radiator to engine; usually the lower) is firm and hot. If out from the radiator is but return to the radiator is not then you probably have a flow problem. Make sure your water pump is turning (and pumping) and check that your thermostat is not frozen closed. A frozen closed thermostat can stop fluid flow causing your engine to overheat and do serious damage while your temperature gauge reads low temp because there is no fluid getting to it to make it sense high temp. Frozen thermostats cause head gaskets to blow and engines to seize. When I replace mine I spend a few extra dollars and get the over temp protected thermostat because they lock open if the engine overheats rather than seizing and jamming closed. I'd rather change the thermostat than blow a motor or blow my radiator cans off. ;-) Good luck and I hope this helps you out.

follow the upper radiator hose from the radiator to engine,you should see a dome like housing,it is under it!

The breather hose should run to the air cleaner housing or intake tube.
Check your radiator cooling fan. If it isn't working the car will run hot at slow speeds or idle then cool down after you get going faster. A quick check would be to turn the AC on and see if the fan comes on. If not try lightly tapping on the cooling fan motor with a wooden broom handle. If it comes on then you have a bad motor.
If the fan comes on with the AC then check to see if the fan comes on after the engine gets hot. If the engine temp doesn't kick it on then the temperature sensor might be bad.
If the fan is ok please post more info on your problem

well, a lot potentially COULD be wrong. here is my list of what to check.

hoses for deterioration and sponginess, its unlikely but possible your hoses are collapsing due to poor condition and not letting water flow through it

check thermostat for proper operation ( remove thermostat, compress spring to open it insert string then suspend it in a pan of boiling water. it will fall off the spring at the aprox. temp its set at. if it is stuck closed then its your culprit)

check water pump ( hard to diagnose, some cars have a weep hole at the bottom of the water pump that drips water while running at any temp. )

check antifreeze dilution and condition, water cools better that anti-freeze 50-50 is recommended but in hotter climates 25-75 is more appropriate. also the dirtier it is the worse it cools

ensure your engine fan is operating by running the car and observing it with the hood open. at a specified temp ( 200-230 F neighborhood) it should turn on. If it doesn't then check your fuses and wiring and repair/replace as needed

finally check for a clogged radiator/ flush it. If the car was bought used or you know for a fact the radiator stop-leak pellets were used in it. you will most likely have to replace the radiator

other factors are engine timing (shouldn't be an issue for your year of car)

I hope this helps a bit

Then replace the thermostat, because if on lower hose not hot and on upper hose scalding hot = antifreeze flow blocked by the thermostat wich remains closed!!!

Thermostat replacing:

hi this could be caused by a couple of things, thermostat not opening is one of the main one, fan heater switch on the radiator is another, and obviously water leak is another, the first one thermostat, can replaced relatively cheaply, for a few bucks, you could do it yourself if you have the correct tools, to find out if it is thermostat, fill water first, run motor till it starts to get hot, feel the hoses on either side of the radiator ( top and bottom hoses be careful not to burn yourself in the process) if one is very hot, and the other is warm to cold, that will be the thermostat, second, the radiator fan switch, fill water, run motor, watch temp Gage, if by the time it has reached over half way on the temp Gage and the rad fan has still not cut in then this is normally a sign the switch on the radiator is u/s and needs replacing ( check fuse for fan to and relay this will also stop fan from working ) also to check for leaks, fill water, ( try not to spill any ) then if available a large cloth or sheet under car, run engine ( making sure first the other items have been checked ) and just observe for dripping water hope this helps

Why was radiator replaced?Did it have heat before ? If it was plugged, the heater core may also be plugged. Try flushing it with a water hose in both directions. I dont know why the botton radiator hose would be cold, the radiator should be a uniform temp and the air coming through the radiator should be HOT, when the engine is at operating temp. What condition was the old coolant? if it was rusty, the water pump may have lower flow than normal.

it may be a little off, but the lower water hose seldom gets very hot,, as its this hose that suplyes the engine with ""cold water"" the hot water comes out the top hose,, drains down the rad and cools on the way down then enters the engine through the bottom hose """if your engine stayes running in the normal place on the gage,,,and not over heating""" why are you spending money for nothing???""
you wont get the bottom hose to run hot unless the engine is cooking

most of the time it is where the outlet radiator hose attaches to the engine.

1. Check the level you filled the coolant to...If you overfilled it this will happen. 2.  Did you add the correctly diluted antifreeze? 3. Check to be sure the radiator is unobstructed