Originally Posted by Modified 99
I[FONT=Arial] just replaced the plugs on my 99 Expedition, 142K now. Your method and information was very valuable. I was apprenhesive about tackeling this project after reading others HORROR stories. The #4 and #8 plugs were a real CHALLENGE but the impediments were overcome. I purchased a 5 -80 ft/lb 3/8 drive torque wrench and torqued the plugs to 17 ft/lbs. I guess I saved about $500.00 over what a dealer would have charged for the same job. I took my time and have only one owie on my left thumb.
Thanks for your wonderful information.
The book (and Ford) call for 9-20 Nm (7-15 lb ft) on the plugs: 17 lb ft is too tight, you could risk stressing the threads by adding that extra 2 lb-ft, go to 11-13 lb ft or as close to that as you can get puts you in the zone, so when I did it, I hit 13 lb-ft to be safe, and this was because I called the factory and the 5.4 designers (who are doing the lifecycle maintenance profile on that engine) and made sure they meant 7-15, and they did, so I opted for the 13 because the engine materials guy said 13 is perfect (allowing for expansion from heat, etc.). Just my experience/$.02. (BTW; I went back and rechecked the torque on all of mine last week after about a month of driving and about 1k miles. All of them are exactly at 13.)
https://www.ford-trucks.com/forums/6...ml#post5503278