possibly a leak in cooling system
The heater core has no overflow hose. Cooling system is a closed loop system and the only overflow hose is the one going from the radiator cap to the reservoir. A thermostat that is stuck closed will cause the engine to overheat. Drain and flush the radiator, replace the thermostat, install a 50/50 mix of antifreeze and distilled water, bleed air from the system. You may also need to replace the radiator cap. Be sure and replace these parts with OEM parts.The heater core has no overflow hose. Cooling system is a closed loop system and the only overflow hose is the one going from the radiator cap to the reservoir. A thermostat that is stuck closed will cause the engine to overheat. Drain and flush the radiator, replace the thermostat, install a 50/50 mix of antifreeze and distilled water, bleed air from the system. You may also need to replace the radiator cap. Be sure and replace these parts with OEM parts.
If you mean the plastic overflow tank, replace it. If you mean the plastic tanks on either side of the radiator core, replace the radiator.
Can be the thermostat which is cheap to replace, or it might be the head gasket which is expensive.
You need to replace the thermostat and flush the system of crud.
It sounds like you may need to replace your thermostat. Even though you have enough coolant in the radiator and overflow reservoir the coolant may not be circulating through the system because the thermostat is not opening. When the coolant can't flow through the engine and radiator it will get very hot and stay very hot. This is usually an inexpensive and fairly easy fix, just purchase a new thermostat and install it or have a mechanic do it for you.
Drain the radiator (dispose of the fluid properly) Remove the hoses from the radiator (upper, lower & transmission lines) Remove the coolant overflow reservoir Loosen the mounting bolts and fan shroud bolts and anything else that is attached so you can pull the radiator up and out. Replace the radiator & bolt it in Reconnect the fan shroud, reservoir & hoses Might even want to flush the radiator to make sure there isn't any debris inside. Fill with coolant & water mixture You might also want to go ahead and replace the thermostat while you are at it.
Drain the radiator. Remove the lower radiator hose from the motor. Unbolt the hose inlet, and remove the thermostat. Replace the thermostat and the inlet, the hose, and refill the radiator.
To replace the thermostat on a 2002 Cavalier 22 Ecotec, drain the radiator and remove the upper hose assembly. Replace the thermostat and refill the radiator.
To replace a thermostat on a 2000 Ford F-250 V10, drain the radiator. Locate the thermostat on the top hose assembly and remove the screw. Replace the thermostat and refill the radiator.
unplug line at bottom of overflow or bottom of radiator
Stuck closed thermostat. Replace the thermostat.
my 1993 Toyota Camry radiator had a hole in it it was overheating. I replaced the radiator. The car is still overheating where is the thermostat located. First, drain your coolant from the radiator. Find your lower radiator hose and follow it to the metal housing. This is the thermostat housing. Remove the 2 nuts with a 10mm wrench. Remove the thermostat and replace with new one and new gasket. Re-install and re-fill your radiator with new coolant. Drive the car with heater running. Allow the engine to cool and top off the radiator. Add coolant to the reservoir to halfway between Full and Low.