I have a 1999 Audi A4 that has been overheating the past couple weeks in a repair shop. Over the last week I have had the thermostat, radiator cap, and the air coolant fan replaced but the car is still overheating. The water pump and the radiator are working as they should according to the repair shop. Then the mechanic looked at the guage and the temperature was 200 degrees. He then took a laser thermometer and a temperature probe and found the temperature to be 170 and 150 degrees respectively. They then replaced the sensor for the guage and the guage was still showing that the car was overheating. Any ideas of what is causing this?

 

Head gasket maybe

 

Turns out the water pump was not good. The impeller inside the water pump was cracked.