YES…this could very well be the case…
make sure you bleed it PROPERLY. sometimes it takes a while for all the air to come out so use the right bleeding tool if you can.put the heat on low in the car and constantly rev the motor to get the tstat to open and for whatever air locks to get out…
with the tstat out the system does ot build up enough pressure to creat a problem but it sucks to drive with no tsat u just burn more fuel and the car takes 4ever to get even lukewarm lol
a good motor does not usually give such a hard time to bleed so when i hear this constant fight just to bleed a motor with a tstat in, that usually sounds like trouble…goodluck