Could be your electric fan on the radiator is shot, or the relay is bad.
Cracked.head
I did a manual flush on the heater core with water from a hot water tank. I flushed a ton of crap out but did have to end up replacing the water pump.
Is you Geo Tracker overheating or the temperature is running almost hot then you need to change you thermostat
The thermostat is stuck open and needs to be replaced.
Check the engine thermostat.
Check your temperature gauge. If it shows the engine is running in the normal range then there could be a problem with the "air door" that controls how much air is brought in through the heater core. Or the core itself is plugged and needs to be flushed out. If the guage shows the engine is running cold , then you should have the thermostat replaced.
It could be you thermostat is bad.take it out and replace They're cheap and easy to install.
I had similar problem with a mercury tracer I owned I had two problems with mine, One the thermostat was faulty(was old and rusted out) and the temperature sending unit wasn't working right ( Fan did not come on at needed temperature 205 degrees) so I had to replace them both. Hope this helps
If your toilet is constantly running or leaking water into the bowl, it may be a sign that the flapper valve needs to be replaced. You can also check for wear and tear on the flapper or if it is not sealing properly when the toilet is flushed.
Thermostat needs to be replaced, it is not opening (most common). Is electric fan on radiator running normally from time to time?
Perhaps plugged radiator - have it boiled out or replaced
have you checked the fan