Two problems related to engine knocking noise have been reported for the 1999 Ford F-250. The most recently reported issues are listed below.
This engine with aluminum heads blew out spark plug numbers 2 and 7. First occurrence on Aug 11 2015 and the next Jan 14, 2016. The first incident occurred driving down a highway and the next occurred starting from a stop light. There was a lag in power and then a loud banging noise and a strong odor of gas. This created an explosion hazard as well as put my safety in jeopardy as well as that of those around me. Since the air/fuel mixture is being blown out of the engine on the compression stroke and the coil firing normally this created a deadly situation. This problem is known to Ford and the company is refusing to do anything about it for all vehicles with these particular engines that are having these problems. This shouldn't even happen with an engine. It's a manufacture/design fault. It needs to be addressed and fixed. The mileage is not the issue as these occurrences are happening on the newer trucks/suvs as well with way fewer miles. That shows it's a manufacture/design flaw and a very serious one.
Loud knocking noise from engine, dealer said drive it until it quits it is a gas engine but it sounds like a diesel,, transmission which is a 5 speed manual comes out of gear when you shift from 2 to 3 this happens about 20-30% of the time at speed of about 15 engine rpm is around 3000-3500, had a proublem with the air bag system when is was 2 days old dealer had the truck for about 3 weeks, not to sure that I want them to tear into the transmission, engine noise the service manager had no idea what that proublem is.