i had a BMW for about 5 months, and it was finicky as all get out in the cooling dept... step 1... replace the thermostat... it's only $4 bucks and takes all of 10 minutes to replace... do that with any car you buy used... you gotta have good cooling... step 2 BURP the cooling system...Ford pretty much has a bulletproof system, but pockets of air in the block, heater core, etc do happen if you drain and refill...YOU MUST... fill the radiator, fill the overflow, run the car with heater on HOT and fan wide open... then let car cool... the valve in the radiator cap will allow the overflow to "top off" the radiator as it cools back down... come back later... top it off again... run car... repeat until level in overflow stays the same... you can buy a reservoir type filler that sits atop the radiator and allows you to run the motor with the radiator cap off and add coolant... hence you essentially "burp" the air out... remember to turn the heater on, or pockets of air will be left there... and you will be cold... good luck..