I have a 2003 expedition with a 5.4 and 110K miles. #3 got ejected friday. A slight ticking noise started about 6 months ago, thought it was an exaust leak, and last week my wife said it was getting louder but neglected to pass that on to me. Anyways, she fired it up friday morning and thar she blows. My question is....any chance it was so far out that the threads are still good? If not, is it possible and or recommended to drill, tap, install insert myself? Which kit is best?
The only way you are going to know is if you can re-thread the spark plug back in the head or inspect the threads yourself. Inspecting them by sight is a bit challenging because you will need to use a mirror and a bright light. Even then you may not be able to see the threads well.
Another member on here had a plug eject and he was fortunate enough to be able to thread it back in and keep going. However, the plug landed up spitting back out again but this time the threads were gone causing him to have the threads drilled out and tapped for an threaded insert which will allow for the a new plug to be installed.
With all of the information above, here is my personal recommendation:
1. If the plugs have never been changed, it's time for tune-up. I have experienced myself loose plugs in the cylinder heads. From searching various Ford forums, common information has indicated that the plugs do sometimes seem to wiggle loose over 100,000 miles. I have experienced two loose plugs myself (not wobbly loose, but not as firmly seated as they should be) when I did my plug change at 100k. I believe, and from communicating with others, that the 100k interval is too long and plugs should be changed at 50k miles instead. I talked with one member who never experienced a blow out and that's what he did in the three plug changes he gave his Expedition. Now, while I'm at it, the thing to remember is getting the installation of the new plugs right. The new plugs should be torqued between 7 - 15 ft lbs of torque. That's all. It's literally hand tight. No more, no less. For the record I installed mine at 12 ft lbs and have had good luck so far - knock on wood!
2. If the plugs were changed at 100,000 miles as recommended by Ford, you need to find out if they were installed with the correct amount of torque and secondly if they used Motorcraft plugs. Most of any plug blowout stories you read involve a recent tune-up or use of non-Motorcraft plugs.
Good luck and sorry for your misfortune!
