Got 115,000 on the original plugs, still starts at the click of the key and after a trip down to Illinois got 22.82 MPG hand figured never going over 70 MPH ,the on board Lie-O-meter did get down to just over 18 MPG this winter with town and country driving but it also got down to - 20 some days, all in all I'm totally pleased with our Expy except for the paint issue on the hatch which is just starting to show with bubbles AND that Aluminum / paint issue will keep me out of a new one for that reason alone.
Who has the most miles out of a set of spark plugs on a 3 valve 5.4,mines an 07
- Thread starter poppie
- Start date
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I’m averaging 16.0 MPG this week mostly city..... my plugs were replaced though.
deweysmith
Full Access Members
I changed mine right around then. They were due. Electrodes were real short.
gixer2000
Retrofit or Bust
I did mine at 110k. I didnt want the misfires to start happening
mcloven
Active Member
150k and need to change soon. runs pretty good, but i do get a miss under heavy loads sometimes. probably change them in the next few weeks.
gixer2000
Retrofit or Bust
I see no issue with doing them frequently. Nothing wrong with staying ahead of it even if it may be a little premature. If I had the time I'd probably do them early also but I have a crazy schedule with 2 athletic teenagers and a 2 year old so I'm usually in desperate need before I can make the time
poppie
Full Access Members
Plugs are cheap and get swapped every 50k in my rigs.
Don’t like the idea of fine threads heat cycling that many times especially of dealing with aluminum blocks.............................Back in the old days with the old style plugs that I changed every 15,000 miles or so and when engines had cast iron blocks I would agree with you BUT with the new Platinum plugs and the SOFT aluminum blocks now days the less you screw with them the better off you will be AND how does replacing the old plugs with new plugs have anything to do with heat cycling and treads, you lost me there, And then there is that issue of the plugs occasionally breaking off while being removed, not a job for the faint of heart and that statement from a guy who in his younger days overhauled engines, https://www.carcomplaints.com/news/2016/ford-spark-plugs-breaking-lawsuit.shtml , I screwed up with this one as we were moving to another state after selling our business at retirement and also building a new home and totally forgot about it ,QUOTE ,(Some owners paid more than $1,000 to have repair facilities use special tools to remove the broken spark plugs),- If your spark plugs were replaced on or after October 23, 2015, the deadline for submitting claims is February 27, 2017.
Antiseize keeps the threads in the block from fusing with the threads on the plugs.
Antisieze will breakdown over time and with more heat cycles. It is especially so with aluminum compared to iron as aluminum heats up much faster. Aluminum is also a much softer metal than iron so once the anti seize has broken down aluminum threads are more likely to fuse to the threads on the plugs.
The issues with the broken plugs generally did not occur at lower mileage interval changes.
You ran into issues as the threads began to fuse, coupled with the 2 piece plug design the added friction on the threads from longer interval changes stressed the area where the 2 parts of the plug were joined and the plug would break.
Back when copper plugs were the norm one did not see this issue as much because a copper plug won’t last nearly as long as a platinum or iridium plug and the plug would go bad and need to be changed out long before the anti seize would break down.
Antisieze will breakdown over time and with more heat cycles. It is especially so with aluminum compared to iron as aluminum heats up much faster. Aluminum is also a much softer metal than iron so once the anti seize has broken down aluminum threads are more likely to fuse to the threads on the plugs.
The issues with the broken plugs generally did not occur at lower mileage interval changes.
You ran into issues as the threads began to fuse, coupled with the 2 piece plug design the added friction on the threads from longer interval changes stressed the area where the 2 parts of the plug were joined and the plug would break.
Back when copper plugs were the norm one did not see this issue as much because a copper plug won’t last nearly as long as a platinum or iridium plug and the plug would go bad and need to be changed out long before the anti seize would break down.
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