Boated with some people last weekend, easy cruise and then pulled kids on a tube and one time when I stopped to pickup kid heard a loud valve tap, was valve train speed and oil pressure was ok. Lifted hatch and tried to figure out what side it was (couldn't tell ). Figured see what it did and after about a minute or two got quieter but present. About a minute later went away totally., it's a 1999 5.0GL with about 1300hrs on it. Oil had about 25 hrs on it so tonight pumped it out, added a couple oz sea foam and ran it on the hose for about 20 moon and then changed it again. Should I start long block shopping?
