Recently, after I shut my car off, I hear a hissing noise. It continues for about 10-15 seconds and then it stops.
The noise is coming from near the engine and the coolant pump.
What could be the problem and how much would you expect something like this to be fixed?
This sounds as though it is the pressure equalizing following shut off.
Are you having a problem with over-heating? Was the A/C on when this condition occurs?
The hissing is the normalizing of the pressures in the cooling system and A/C lines.