water pumps have a seap hole that will leak when they go bad ,visually inspect this first
Pressure test the cooling system Monitor antifreeze level
heater core has a pinhole leak! Only shows when under pressure .remove and replace not good to breath antifreeze vapers!
You have a blown head gasket. Check the oil and antifreeze, they may have mixed. Have a mechanic pressure test your cooling system.
Through the radiator cap no... But it does allow the antifreeze to come out through the cap if the pressure gets too high.
Your heater core has a leak, have the station pressure test your cooling system if it does not hold pressure you a leak in system
To change the antifreeze on a 2003 Alero once the car cools remove that radiator pressure cap. Pour in a gallon of pre mixed coolant.
The fuel pressure regulator is underneath the fuel filter bowl on the righthand side of the motor. It has a two wire connector plug that goes into it. Also it is underneath the oil pressure sensor switch.
Pressure test system t determine where leak originates
Have cooling system pressure tested to determine origination of leak
The oil pressure valve is on the back of the engine passengers side above the oil filter. It is adjacent to the firewall. If you open the Hood go on the passengers side you will see it with a metal cover on it
It runs from the oil pressure gauge to the sending unit on the engine.
have the coolant system pressure tested to help diagnose your problem.