Two problems related to loud engine noise have been reported for the 2004 Ford Expedition. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2004 Ford Expedition based on all problems reported for the 2004 Expedition.
Spark plug blew out of block: out of nowhere, my spark plug blew out of the block on my 2004 Ford Expedition. My car drove perfectly fine coming home from work. I parked it in the driveway and a short time later went out, started it to leave and it popped and had a low rumbling sound and a burning smell. Threads possibly stripped.
3 weeks after 60,000 mile check up, my wife turn the vehicle on and it made a loud pop noise then engine started vibrating abnormally and making a loud putt-putt noise. She drove the vehicle home approximately 1/4 mile and it smelled like it was burning. My mechanic said, it blew out the #5 spark plug, and that this is a very common problem on a Ford triton engine.