z24 spark plug issue. Noob needs help!

[JohnNRiner]

I had the heads in my 84 4x4, 2.4 reworked few months back. This past week I had one of my exhaust plugs blow out of the head while driving. Doesn’t appear to be stripped or cross threaded. Tightened it back in and all was well. A couple of days later it had started backing itself out again. I am obviously not a mechanic or even claim to be mechanically inclined lol. I have no one around to help or advise. Can anyone help me? Thank y’all so much. 

[DIY 1985]

I had an exhaust plug loosen up once due to debris in the way upon initial installation.

 

So, it could just be debris in the way of a properly torqued seal?  For a head that is dirty, I scrape the outside of where the plug washer seats, gently, to remove gunky dust, wipe with a gasoline-soaked q-tip, use compressed air (if I have it), etc.  For the threads, themselves, I rinse a plug in gasoline, install wet with the socket (by hand, no wrench).  The gasoline allows the plug to clean the head's threads, and eventually go all the way to the seated spot without the torque of the wrench, ensuring that the threads are clean.  Back the plug out again, wire toothbrush the threads of the plug, dip in gas, reinstall without wrench, repeat until clean and fully seated.  Mop up the gasoline with more q-tips.  When I finally install, fully torqued, I use nothing more than motor oil as an anti-seize.  Clean threads will allow the torque applied to compress the gasket/washer which holds the plug stable against the head thru temp swings, etc.

 

You might have bad plugs where the thread isn't up to proper tolerance?  The rumor goes that there are fake ones out there, but, I wouldn't be able to tell the difference, and how true are rumors anyway?

 

Some plugs have a gasket/washer that isn't captive on the base of the thread, so make sure that the loose plug actually has one.

 

You might just need to install a thread-repair-insert?

 

 

Edited July 4, 2021 by DIY 1985

[datzenmike]

They should also be NGK, the same as used by the factory. Type " How to spot fake NGK spark plugs" into You Tube. If you find any spark plugs at a ridiculously cheap price they are probably fake. Amazon and e Bay often sells them. Buy from a reputable dealer. Check your 'new' plugs against an old plug before putting them in.  

 

 

 

http://4.bp.blogspot.com/-4Vm_v6TXUfE/Tgkb6FD0_8I/AAAAAAAAEC8/s-Ws5PgXPn8/s1600/photo7.jpg

[Charlie69]

Buytour plugs from a reputable auto parts house NOT Amazon!

[captain720]

Are you torqueing them to a spec or just hand tightening them? Does anyone know the torque spec on our spark plugs? I usually just put them in and havn't had a problem......