I was able to successfully change the spark plugs around 75k with no issues breaking off the two piece plugs. I replaced them with Motorcraft plugs. Fast foward to the present at 133k miles and due to the poor design of the spark plug wells, trash (dirt moisture ect) easily goes down the wells. I found this out when I had cylinder 2 misfiring. After pulling the plug and seeing the ignition pack and spark head were fouled considerably (so bad that I had to clean the well before I could even get a socket around the plug), I decided to replace all the packs and plugs.
I was successful in changing all the plugs except #3 which would not come out. I have tried every method I have found for removing a frozen plug which are the following:
"Spray a light penetrating oil and let sit overnight". I let it sit for 3 days, trying every day including the initial day I sprayed it. "Tighten slightly". Would not tighten.
I had a long breaker bar on it and it still wouldn't budge. I refuse to use a cheater bar because at this point, the amount of torque I have applied so far already could have sheared the plug, which would be a nightmare.
The only thing I have not done yet is run the truck to let it warm up before trying to remove it but I have seen mixed reviews about it possible shearing the plug easier when hot.
Your insights are appreciated.