One problem related to engine clicking and tapping noises has been reported for the 1997 Ford E-350. The most recently reported issues are listed below.
1997 Ford e350 v-10 engine van blew out the number 4 spark plug. Loud popping sound followed by loss of power and strong fuel smell. Also had a neighbor with an f-150 that had same problem and truck burned to the ground in under 5 minutes.