Once I start moving again the engine temp cools down. Any ideas?

 

Loose belt? Bad thermostat? Non-functioning coolant fan? Low coolant? Failing water pump? Could be any of theses things. How many miles on the car? Check the belts first to see if they seem tight, then check your coolant level. Make sure the coolant to water mix is 50/50. When was last time coolant was changed? If all ok there, then check thermostat. Radiator may also have leak or blockage in it, so look at carefully if thermostat seems ok. Keep me posted on the your results.

 

Check the radiator fan too.