The electric cooling fan or cooling fan temp sensor may be faulty.
A car running hot after it has been started could be blown head gaskets. The thermostat may also need to be replaced.
Maybe you need a freon boost.
Cracked.head
Sounds to me that the thermostat is in backwards.
I suggest replacing the thermostat, that might work.
Is the thermostat in backwards??? it depend on where u live hot or cold weather... german cars are made for cooler weather... this will efect the way ur car will run
Check into the temperature control valve--this is different than the thermostat.
Try checking your coolant level. If that's fine it may be your thermostat staying open and it may need replaced
Sounds like you still have air in the system. Make sure it's topped off and bleed all the air out.
MY CAR WAS DOING THE SAME THING NO HOT AIR COMING OUT OF THE HEATER I CHANGED THE THERMOSTAT. IT WASNT THE THERMOSTAT. I GOT TO CHECKING AND THE SEAL IN THE WATER PUMP WAS BAD. I REPLACED THE WATER PUMP AND IT WORKS FINE NOW.
Is you Geo Tracker overheating or the temperature is running almost hot then you need to change you thermostat
You need to change your thermostat in the car.