Please Help. My engine is overheating, I just replaced the thermostat and water pump. My heater isn't hot either. I had my car for 5 years and I have never flushed it. When I drive my car cools a little bit but when I idle it heats up.

 

Check to see if a fan is stuck. It might be a water pump or low oil problem.

 

did you ever figure out what the issue was? Im having a similar situation. Replaced the thermostat and water pump and still overheating/heater blowing cold.