Escort wont shift
 

Hi, I am new here and need a little help. My son has a 95 ford escort which needed a new thermostat the other day. Before the new thermostat was installed the car had no problems shifting at all and now after the new thermostat now the car will not shift until it reaches 5000 rpms. It doesnt make sense that one would have anything to do with the other and just seems odd. If anyone has any ideas what could be wrong I am open to suggestions. I am stumped.