your radiator needs to be replaced
Normally a sign of a coolant leak in the oil cooler. Replace ASAP.
A Ford Focus needs anywhere from 4.5 to 6 quarts of motor oil. The Ford Focus was fist produced in 1998.
A four cylinder 2009 Ford Focus hold 4.5 quarts of oil.
According to the 2002 Ford Focus Owner Guide : ( 5W-20 ) engine oil is recommended
In the oil pan, in the engine.
if it is a new ford focus then no, alot of new cars have regulators on them.
No
diesel
The exclamation light, on your Ford focus, is a reference to the oil needs to be changed. The light can be reset by changing the oil.
Motorcraft oil 5w20
Remove oil pan
When you change the oil and oil filter.