so i had a very slight knocking in my engine, i changed the oil and it went away. about 700 miles later my engine was about a quart low on oil and the knocking came back. the car was sitting for about three years before i bought it. what could this noise be and why does it go away and then come back? also is it normal for my car to be using this much oil? and i feel alot of heat coming from the slit where the e brake is out of the center console. is this normal?