Blowing out spark plugs

[jrjr]

I have read many references here to blown out plugs and I believe it only pertains to 3V 5.4L engines....

Only thing is that it's the 3V 5.4 that breaks plugs. Shouldn't have an issue with the 2V (on some 03s, and anything before 03).

Is this assumption correct or do both the 4.6 and 5.4 motors have this issue? Maybe the quote above actually meant 'breaking' plugs when torquing them and not blowing them out of the head.

I also have read to use only Motorcraft plugs and to not use never-seize so I will stick to that plan. I should be getting my Expy in a couple days and this will be good info to have. Man I have read a lot of threads here!! Thanks for all the info.

 

[toms89]

The spark plug ejection issue is a problem with the 2v heads. They only had 4 threads in the heads?! This made proper torque a necessity. Too little and they come loose. Too tight and you risk damaging the threads in the head. I still used anti sieze as I did not want to risk corrosion...again damaging the threads in the head upon spark plug removal. I have heard of many spark plugs getting siezed up in aluminum heads through the years before I ever even heard of this ford plug launch issue. Want you to understand where I am coming from. I personally dont think anti sieze contibuted to plugs coming loose if properly torqued. But there are many that recommend not to use it. I also prefer to err on the high side than too little torque.

If too little torque they come loose and then you only have the top edge of even fewer threads holding and the pressure can eject them damaging the threads in the process.

You reseach it and you will find many recommendations....you will have to roll the dice and decide what is best for you.

 

[jrjr]

The spark plug ejection issue is a problem with the 2v heads. They only had 4 threads in the heads?! This made proper torque a necessity. Too little and they come loose. Too tight and you risk damaging the threads in the head. I still used anti sieze as I did not want to risk corrosion...again damaging the threads in the head upon spark plug removal. I have heard of many spark plugs getting siezed up in aluminum heads through the years before I ever even heard of this ford plug launch issue. Want you to understand where I am coming from. I personally dont think anti sieze contibuted to plugs coming loose if properly torqued. But there are many that recommend not to use it. I also prefer to err on the high side than too little torque.

If too little torque they come loose and then you only have the top edge of even fewer threads holding and the pressure can eject them damaging the threads in the process.

You reseach it and you will find many recommendations....you will have to roll the dice and decide what is best for you.

So, is the statement true that Expys earlier than 2003 had 2V heads? If so then my 4.6 1997 is one of them.

Never seize would be good on dissimilar metals for sure to eliminate ion exchange but the Motorcraft plugs, as I read it, are aluminum threaded so they should be compatible with the aluminum heads. Still, it would not be a bad idea imho to use it and I will most likely do that. One thing that never seize will provide if nothing else is a uniform torque value but it should also provide for more reliable plug replacement in the future as well.

 

[99 Expy]

I think I've only heard of the problem with 5.4 heads. I have a 99 4.6 and changed the plugs on mine and had no problems. I didn't use anti seize or anything and I recently pulled a few plugs to check them, and everything went well. I would recommend using factory plugs and having plenty of time to change them. It took me about 3 hours to do mine.

 

[Stoned06]

AFAIK, The 5.4 had 2V heads up to (including?) 2005. The 4 thread heads (those with the blown plug issues) disappeared in 2003 when they switched to 8 thread heads. The 3V heads have the seizing plug issue.

 

[alaskanexpy]

i'be blown one, i caught another right before it blew...thank god.

 

[2000eb]

anti seize or never seize actually changes the tq there are tq charts you could use to compinsate but i dont recommend taking the chance dont use either use motorcraft plugs cause they have the sluminum threads and tq to recommended spec. i have tq charts somewhere i used to work on helicopters where tq was extremely important thats where i learned how much all of that crap can change the actual tq

 

[jrjr]

So by all of this I would surmise that my 97 4.6 is not the 2V head that blows plugs by reputation and also to not use anti seize. Maybe I will be able to see the threads in the front holes with an inspection mirror. Maybe the plugs will have been done already. It does run really well. Time will tell.

There aren't a lot of posts on here about blowing plugs, a few though. Maybe we need a poll....

 

[mmrseed]

I wouldn't make many assumptions about the safety of the 2v 4.6 vs 5.4 etc....Talk to the mustang guys (as I have in my local club) and you will know that all the 4.6 2v mustangs (96-04) all were subject to thrown spark plugs after their first plug change. I would assume it's the same for the expy and its motor

 

[rburch]

Ford spark plugs blowing out is a common problem with Triton engines in Ford F150, Mustangs, Crown Vics, Vans, Expeditions and motor homes made before 2004.