Engine Cooling problem
2007 Ford Mustang 6 cyl Two Wheel Drive Automatic 48,000 miles
Harmonic balancer broke on car while at the repair shop getting fixed the tech discovered the water pump was leaking and replaced it with a motor craft pump. When car was picked up after hours the car had a sweak when we started it. A few days later the car heater stopped working. I took the car back and the tech flushed out the heater core the car was also getting hot, the guage would go all the way to hot but would go back to the half way mark right away Tech said the car itself was not getting hot, I picked it up and after three days the car got hot the guage went all the way to hot but as fast as it went to hot it will right back to half way mark. Back to the shop, again he flushed out the heater core and replaced the resevor bottle and put a therostat in. I picked the car up and got about 2 miles and the guage went all the way to hot and backl down, as this happened the heater in the car went cold like the a c was on. I had a wrecker take the car back and the tech says it has a cracked head the car runs great no miss or smoke the heater is not getting hot if the engine runs hot, but the guage only goes to hot for a minute and right back down. You can smell antifreeze but the car does not have a bad hose or any sign of a leak. After driving the car about 10 miles the bottom radiator hose is barley warm and the heater hose on top of the engine is cold. I am wondering if you have any ideals what might be wrong or do you think it does have a cracked head?