Had a new thermostat fitted but i still have no heat ,the hoses that go into the engine block,as you look at it from the front ,the left hand hose which goes to the bottom of the radiator and thermostat housing is stone cold and the other one with the swirl pot in the line is roasting, as are all the others.I seem to be drawing air too as when i open the expansion tank it bubbles up and then the stat hose warms up , the system had been bled so there was no air locks.
Second one : when the car hits about 40 -50 mph it stutters badly like you were touching the brakes then it clears,happens every time

maybe i should just burn it nothing but hassle,ford garage here is no help either

 

the car is?

 

its a 1992 4x4 sierra cosworth