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John Sheuring

Junior Member
So, the spark plug for the 3.7 is the Motorcraft SP-520? I know that O'Reillys does not carry Motorcraft plugs here in the Raleigh-Durham, Area. Are you going to replace the coil packs as well? Considering that you have to remove the intake plenium to get to the rear plugs?


I just wanted to know what size socket I will need when the time comes to change plugs. That will be a long time in the future, as my 2014 has 18,000 miles on it and my 2015 has 9,000. I owned 3 auto repair shops for 45 years and I am now retired. I just don't like any surprises. I have both 5/8" and a 13/16" sockets, and have just gotten both 9/16" and a 3/4" socket. For 50+ years the 13/16" and more recently the 5/8" sockets fit everything. NO MORE, now they've complicated it---Every car and machine take different size spark plugs. This is one reason that automotive repairs are so expensive----The amount of $$$$ invested in tools !!!