One problem related to engine noise has been reported for the 1999 Ford F-150. The most recently reported issues are listed below.
I have a 1999 Ford f150 with just over 60,000 miles on it. It has been maintained very well and has had no problems until now. While driving to work on 9/20/05, my engine sounded like it blew up. What actually happened was my #3 cylinder spark plug blew out. Thankfully it did not cause an accident. After investigating how to fix the problem I learned this was becoming very common with Ford triton motors and would cost appx $3000 to repair. Ford offered no help other then for me to bring it in for the expensive repair, with no guarantee it would not happen again. I thought the truck would last much longer then 60k miles and feel like I bought a lemon.