My 2003 Elantra has been draining the coolant the past few days. I received this car from a family member who had the radiator flushed. My thought is that the mechanic didn't fully fill the radiator so it keeps draining the reserve. This however confuses me.

There is a knocking type noise that seems to be coming from behind the radio or into the passenger front tire region. Usually between 25-45 mph is when it is most apparent. I first noticed this after driving problem free for approx 250 miles.

Any thoughts welcome

 

One issue was I needed a new fuel pump. �� The second issue was that I needed a new clamp for a hose that a mechanic left off after flushing the radiator.