I really need help!! My engine was just rebuild and I went to get it on Friday . I and the mechanic drove the car for about five minutes and no problem occured, after then we let the car work for ten minutes and after the heat get around 90 degrees the fan started to work . Until here no problem . I got in the car and started to drive, after a few meters the car suddenly stopped and I checked the heat it was over 90 degrees . The main point is there was no problem until the car was driven ,everything worked okay . Today we checked the radiator and the machanic said that we will have it cleaned and make two more lines to make the water get cooler. I really don't know if this is the problem . What do you think guys ?? please reply me as soon as possible
Thank u all

 

90C is not a problem. If you are seeing temps around 110C, then there's a problem.