I recently bought a used 2002 Mazda Protege. Driving yesterday around 20 miles, the temperature indicator shot up straight to H and I rushed back home safely. Coolant seems to be leaking from under the radiator as I am leaving patches on the road wherever I park. A day before I bought this car, the seller experienced the same problem and the mechanic told that one hose was missing and that the coolant would have to be filled always directly into the radiator. This is all I know. But I see a hose from the radiator to the reservoir. Can somebody please tell me which other hose was he talking about?
Thankss

 

Whose mechanic told? Yours or the seller's?

If it was the seller's mechanic find your own one. If you want any reliability of your car the cooling system must function properly.

 

Sounds as if you have a leaking radiator or radiator hose. I would recommend taking the car to a shop so they can fully diagnose the concern and repair the problem.

I would not recommend driving the car with it overheating as it is unless for very short distances.

 

My recommendation for what it's worth, rent, buy a radiator pump. This replaces the cap with a hand pump as to pressureize the system. With 12-15 psig, inspect the system to find out where the leak is.