Wow.. So I installed a set of these sparkplugs today, number 3 cylinder, the plug was seized and wouldn't come out, kept getting tighter and tighter, I went back and foward but was getting too tight and was really worried it could snap or even strip the thread completely..
Got some fuel applicator spray from a friend at work and luckily managed to get it out.. SLOWLY... The lower 3rd of the thread on the old plug is really damaged, will get a photo tomorrow. The new plug didn't seem to want to screw in by hand and felt like it could cross thread so I tried another new plug and same deal, I got one of the old undamaged plugs and sprayed it with the same stuff and carefully screwed it in and it seemed to clean the thread as the new one went in fine after that..
I'm really hoping the thread in the cylinder head is ok.. the new plug went in just fine, just a bit tighter than the other three. But felt smooth. Engine was hot at the time.
Runs fine and seems to go a bit better, little more torque and power.
https://whoosh-motorsports.myshopif...g-set-4-pcs-2014-2019-fiesta-st-free-shipping
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