just purchased my first ford...03 cobra...I drove the thing 250 miles home no prob, got it home....no heat, heater hoses not getting hot, so per this forum put car on ramps replaced thermostat, refill coolant through plg in intake, ran and bleed, ran and,bleed several times heater began to work, car seemed ok..now i drive a while, 10 miles or so heater quits and car runs hot. take it home on ramps again open bleeder plug got some air, but this cycle keeps happening car still running hot and heat goes away...getting a case of the a$$ already...also the thing "clunks" in the rear. there seems to be exsesive lash in the drive train could this be half shafts? the pinion support bushings dont look that great either please help!!:cuss: