I have a 1998 chevy Malibu. I just had the engine replaced, and everything was working fine that first day after replacement. but now the car engine overheats and fast too.it only takes a few mins of driving for it to fully get that high point. And I also here this thumping or popping noise in the radiator. Also in the upper hose the thumping can be felt. That upper hose is hot too. Does anyone know what this could be?

 

any ideas?

 

sounds like an air pocket......let the engine cool, open the rad and fill it up