Blown out spark plug
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Blown out spark plug
2000 Excursion with the 5.4 in her. Lots of miles. Used only to tow a travel trailer. Blew out the #3 coil packet and spark plug today. Have to pull the head for sure. My question is why? Is there a more severe problem as to why it did this? Or is my old girl just worn out. 270,000 miles.
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There's a bunch of great posts on this site regarding this it is a common problem with the early 5.4 and 6.8 engines. Had to do with the number of threads that the soak plug threads in to, as well as dirt in the threads,and the torque of the plugs.
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From: Rowlett,TX
This freaked me out a bit doing my first plug change on the EX after I got it. It's a 2003, I read after the change that older 2003's had more threads added to prevent that from happening, or at least lessen the frequency on the 6.8's. Making sure the threads are free of any debris and using proper torque specs comes in handy. Probably the only thing I actually take a torque wrench to.
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From: Media PA
2000 Excursion with the 5.4 in her. Lots of miles. Used only to tow a travel trailer. Blew out the #3 coil packet and spark plug today. Have to pull the head for sure. My question is why? Is there a more severe problem as to why it did this? Or is my old girl just worn out. 270,000 miles.
No need to pull the head, there are repair kits for this problem that use very good inserts that are stronger than than the factory setup. Time-Cert (spelling?) is the recommended repair kit, it can be rented from a few vendors or the whole kit can be bought for $400-ish.
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Pulling head
I have decided to pull the head to fix the problem. While I'm at it, going to do a few other things that need some TLC. Head gaskets need replaced. Exhaust manifold gasket. But here is my question. Since I will have the head out, should I just fix all 8 spark plug sockets? Seems logical to me.
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Joined: Feb 2011
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From: Thousand Oaks, CA
Repaired it with the Time-Sert and has been fine.
If the heads are off I would put inserts in all the spark plug sockets.
Seems logical to me, too.
Ford should have done this at the factory.
From my reading it seems that leaving the plugs in for over 100k allows the plugs time to work loose.
The threads are torqued to provide pressure for the seat to seal.
With the early 4 thread heads when a plug gets loose there aren't many threads left before it strips.
The later 8 thread heads will allow the plug to spin a couple of turns before there are only a couple of threads left to strip.
You might hear exhaust leaking before that happens.
My early heads blew without any indication of exhaust leak.
Changing the plugs at 50k and checking the torque one more time at 10k seems to resolve the problem since the plugs do not have time to work loose.
My plugs usually look like they need changing at 50k on my 5.4L and 6.8L.
One case had a plug blow at 68k on an early 6.8L, and there have been people have them blow on the later heads, too.
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I recently had the #3 plug blow out on a 6.8L.
Repaired it with the Time-Sert and has been fine.
If the heads are off I would put inserts in all the spark plug sockets.
Seems logical to me, too.
Ford should have done this at the factory.
From my reading it seems that leaving the plugs in for over 100k allows the plugs time to work loose.
The threads are torqued to provide pressure for the seat to seal.
With the early 4 thread heads when a plug gets loose there aren't many threads left before it strips.
The later 8 thread heads will allow the plug to spin a couple of turns before there are only a couple of threads left to strip.
You might hear exhaust leaking before that happens.
My early heads blew without any indication of exhaust leak.
Changing the plugs at 50k and checking the torque one more time at 10k seems to resolve the problem since the plugs do not have time to work loose.
My plugs usually look like they need changing at 50k on my 5.4L and 6.8L.
One case had a plug blow at 68k on an early 6.8L, and there have been people have them blow on the later heads, too.
Repaired it with the Time-Sert and has been fine.
If the heads are off I would put inserts in all the spark plug sockets.
Seems logical to me, too.
Ford should have done this at the factory.
From my reading it seems that leaving the plugs in for over 100k allows the plugs time to work loose.
The threads are torqued to provide pressure for the seat to seal.
With the early 4 thread heads when a plug gets loose there aren't many threads left before it strips.
The later 8 thread heads will allow the plug to spin a couple of turns before there are only a couple of threads left to strip.
You might hear exhaust leaking before that happens.
My early heads blew without any indication of exhaust leak.
Changing the plugs at 50k and checking the torque one more time at 10k seems to resolve the problem since the plugs do not have time to work loose.
My plugs usually look like they need changing at 50k on my 5.4L and 6.8L.
One case had a plug blow at 68k on an early 6.8L, and there have been people have them blow on the later heads, too.
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I would change those two and check the tq maybe set the tq a few lb's lower just to be safe, I was surprised all of mine but the blown plug came out with no issues.
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