Our aveo has about 200000 miles on it been running a synthetic blend and changing the oil every 3-4000 miles. It has had a tap for quite a while now but extremely minor and would go away after a few seconds upon cranking and then would stay tapping a little until we change the oil later in the mileage as the oil gets broke down. Well now we let the car sit for the last few weeks while we painted it and now the tap is pretty loud can hear it really well even with the hood shut, and does not go away or quiet down, we have not drove it yet because of this. The oil isnt due for a change for quite a while(cant remember how long) I removed the valve cover and the tarnish is a more redder brownish on the back drivers side of the head than the rest of the head, like it isnt getting as much oil as the rest i would say. I will try to get pics up of it, but basically where is the passages for the oil to come up so i can see if it is blocked by buildup? Thanks in advanced.