I have a 2004 5.4 3V with 105Km's. Was just wondering how many K's the factory plugs go before changing. I have not changed them, I bought the truck with 100K's on it, not sure if they were changed prior to that. My truck seems to be down on power, but not sure. Fuel economy seems pretty good, I can get 850K's on a tank of fuel, with out taking it to the low fuel light.

THx

 

105,000 kilometer = 65,243 miles. The plugs are rated for 100,000 miles or 160,000 K

Most people change the plugs early due to the carbon build-up problems encountered on the arc shield of the plug. If you search this site you will find thousands of posts and directions on the subject. Be sure to follow the latest TSB regarding the plugs removal, and it would also be a good investment to get a removal tool incase any of the arc shields break off in the head. Many people are also using a new one piece plug by Champion. I’ve never been a big fan of Champion, but I haven’t read anything negative on these new plugs. I changed mine out at 28,000 miles and didn't have any problems. Good Luck! <?xml:namespace prefix = o

 

I just did mine last Saturday with 115,000 miles on them. I read that they were breaking as low as 15,000 miles. I figured that I would get the life out of them. I went with the factury plugs and the power deffenently came back. I would recomend to buy the tools first before doing the job. I went strickly by the TSB and I still broke two, #4 and #7. I then had to rush and look for the tools. The porcolein puller didn't work at all even after three tries. But I recommend buying the sleeve puller. You will have to break up the porcolein about a 1/4 0r 1/2 inch so the tap will bite into it. It will the push the pocelien down an 1/4 inch to the gap. If you look at the new plugs you will see what I mean. Good luck and be prepared with tools and time.