Blew another spark plug!


New Member
Apr 5, 2005
Chico, CA
About 6 months ago blew cylinder 2 plug, got it helicoiled and was perfect. Well the other day blew the cylinder 1 plug. Could this be a internal problem or just the ford heads threading so crappy. Should I get it helicoiled again or just get some new heads? How hard is a head install? Thanks
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First time it blew it was the stock plugs, had it fixed and all of them changed from a local ford dealership. Just got ahold of the dealership and there going to fix tomorrow for an hour labor charge. But do you think there would be any internal damage?
Usually the cause of this is:
a) changing plugs when engine is hot
b) tightening plugs too tight and damaging the threads
c) not tightening plugs enough and having them back out and blow out when there are only a few threads holding the plug in
d) not using anti-seize, and the threads are damaged upon removal

If you can fix it with a heli-coil do this to the others.Wait till engines cools, remove the plug caps and spray down the holes with wd-40, let it soak over night. Remove the plugs and coat them with anti-seize and reinstall using a torque wrench to 10-12 ft lbs
Do not repair spark plug port threads in aluminum cylinder heads-
Unapproved usage of helicoil for serice
Some engines equipped with aluminum cylinder heads may exhibit spark plug port(s) with stripped or missing threads, "Do not" service stripped or missing spark plug port threads by using "helicoil" or "tapersert" repair kits. It is likely that additonal engine damage or engine failure will occur after an unsuccesful atttempt to service the cylinder head spark plug reports with "helicoil" or taperset. The only authorized service procedure is to replace the cylinder the cylinder head assembly when spark plug port threads are damaged is to replace the cylinder head assembly when spark plug port threads are damaged and in need of service, refer, to the pertinent workshop manual (section 303-1) for cylinder head removal and installation procedures. Note: When servicing spark plugs for any reason , do not use air or powertools and take care to ensure that spark plyugs to not crossthread.