so we recently bought the car and about half way home of our like 100 mile journey to get it and it begun over heating. we towed it home and took it to out mechanic who said it was the heater core (there was coolant in the passenger side floor board). he fixed that and he said it
was overheating still. he took out the thermostat and left it out and its still overheating. any suggestions about what it could be..? Thanks!

 

My best advice would be to get the cooling system flushed. It is possible the cooling system is plugged up somewhere. The mechanic can also see if the radiator cap is bad, or the water pump is bad. The radiator itself isn't an issue - if the radiator goes bad, it would be spewing coolant.

As a side note, having no thermostat just means the engine takes longer to warm up.

TS