Luckily (knock on wood) this has not happened to me, but it scares the sh_t out of me. Can anything be done to prevent this besides making sure they are tight every so often? I don't want to torque them down too hard for fear of jacking the aluminum threads. Anybody have any tips on this?

 

Had it happen twice. same plug. After the second time I was told to torque the plugs to 26lbft instead of the normal specs. Never had a problem with a plug since...

 

This seems to be a fairly common problem with Mustangs for some reason. I mean it does nto happen to everyone, but it happens. The more you pull the plugs, I would think the better the chance of having an issue.

 

Why would there be more of an issue the more you pull the plugs?

 

aluminum heads and steel threads will wear down the threads i suppose

just factory torque them and you shouldnt have any issues. i havent had one blow out and in delaware my car has seen 15#'s off boost in 30* temps at the track. thats only happend 2-3 times in its 20k miles.

 

26ft lbs is way too much. 13ft lbs is perfect. The use of anti-seize is debatable. I dont use nor recommend it and neither do the guys at Modular Powerhouse. Ill have a write up on my site soon about changing plus.

If you're getting spark blow out then you need to tighten the gap on your plugs. Whats your set up caballo.

 

I haven't had a blow out, thank God, I just have seen a lot of threads on the topic lately and it has me scared. I went back through and made sure they were all tight today. I guess I will just do periodic checks to make sure they aren't coming loose. I would estimate that they all are torqued between 11-15 lbs.

I'm running motorcraft AGSFxxxxx (I can't remember the numbers). They are the full length thread plugs and I believe they are platinum tipped.

 

Are you talking about throwing a plug, or blow out. Blow out is nothing more then having the spark itself blow out and not ignite the fuel. This is a pain, but not a bad problem. It comes from having the plugs gapped too wide and generally does not happen unless a nitrous or turo/super charger application.

The more you pull and install your plugs, the greater the chance of cross-threading or not putting them in correctly. This can cause the entire plug to shoot out. This is a bigger problem, but not the end of the world.

 

What I mean by blow out is the entire plug actually blowing out of the head.

 

Apparently the issue was w/ the original plugs for the modular engines having only like 6 threads on it. However, the full length threads are suppose to fix the problem. I wouldn't worry too much about it since my dad's F-150 has 200,000 miles on it and hasn't thrown a single one. However, don't feal alone, because the Hemi engines have the same problem.

 

Is there a reason why you are concerned? You have a greater chance of hitting a deer then throwing out a spark plug unless you actually think you installed a plug wrong.

If this should happen, you have three options:

1 - Just screw the plug back in. This will only work if the plug twisted itself out because it got loose, but not if threads are ruined.

2 - Repair the threads on the head. This is a step better then a Mickey-Mouse fix and is a bit better then temporary. If you have a high hp application, I am not sure if this is an option. Cheap fix if you can do it yourself.

3 - Pull and replace the affected head. This would cost about $1000 for head and labor on one side of the car I would think, but I am not sure. The good news is that there are a lot of used stock heads out there. ****, I threw the ones away from my old motor....they are just paper weights if you don't need them. If you find one used, it will be cheap. Some guys might use this as an excuse for ported heads.