Spark plug ejected Ford 5.4

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This is the first time I had such an experience. I was driving a 99 F250 when it just went BANG! I was surprised the engine didn't stall. Somehow I made it back to the shop. How much damage did I cause by driving it like that? It was just over 2 miles in city traffic. Only 1 plug lost and coil destroyed, boy did that truck run poorly.
 
Well, the bad news is its a relatively common issue.

Which means the good news is it is repairable and there are reputable repairs for it - as identified in the post above.

Honestly probably didn't do any additional damage to the engine.
 
USUALLY, you will just need to pay for the insert repair (labor, insert) and the cost of a new coil.
 
Originally Posted By: 901Memphis
Isn't that pretty bad for the cat getting fuel into it?


The PCM will detect the severe misfire and cut off the injector for 30 seconds at a time. Then it turns it back on for 200 revolutions of the engine before shutting it off again.

Short-term (a few miles) this will prevent the cat getting too hot. If you have to drive it longer, I recommend unplugging the injector. I drove my CVPI 160 miles with a blown out plug by unplugging the injector.

Oh, and unplugging the MAF helps get some of the power back too. My educated guess is with a cylinder drawing air from the plug hole, its way under representing the load on the engine. Letting it use the Failed MAF table in the PCM is a little closer to reality.
 
What exactly causes this to happen? Is it just that there are too few threads in the engine? Are these repairs permanent?
 
Low thread count along with low torque value (as a result of the lack of threads). What Ive experienced is the plug working loose over time for whatever reason. Probably expansion and contraction.

The reason I know this, is the day before mine blew, I heard a ticking while I was in a drive through. My window was open and I was hearing the sound reflect off the wall. It was too light to hear otherwise.
The ticking was the plug leaking as it had come loose. I changed the plugs on a friend's F150 with the same engine and it had a plug that was loose too. The coil pack boot was totally cooked.
The difference is his engine was a 2005, so it had the updated '8-thread' heads and it survived this until I replaced it.
Take a 4-thread head and loosen the plug a turn and you get a time bomb.
There is a place advising using a very high torque value on the spark plugs to prevent them from loosening, but, Ive checked and the stock value of 10ftlbs is about all you want to give a 4-thread head. Taking into account the strength of the cast aluminium.
An 8 thread head is much better in that respect, and 18-22ft-lbs is doable. So, I did tighten the plugs on the F150 to 18ft-lbs.

The repair is pretty much permanent. It converts it to an 8-thread hole, so barring spark plug installation error at some point, its permanent.
 
Originally Posted By: Rand
http://castingrepair.locknstitch.com/viewitems/spark-plug-hole-thread-inserts/ir-insert-kits-for-ford-modular-and-triton-engines?&bc=100|1002|1006

IIRC thats the Ford preferred repair method (dealer authorized)

http://www.locknstitch.com/pdf/Sparkplug 14mm insert instructions.pdf


+1 The LOCK-N-STITCH is the only correct method of repairing the threads on these engines. Messing around with Heli Coils just ruins the head and should never be used.
The Heli Coil presents 4 problems, without the bushing it is impossible to get the reamer and tap dead straight in the bore, it does not transfer heat properly away from the plug in the aluminum head, the seat is not correct for the plug and can leak and the tang that gets broken off in the coil is steel and can damage the cylinder.

This repair should only be done by a pro with the LOCK-N-STITCH tools and experience using it or the dealer, this is a one shot deal there is no redo.
 
Originally Posted By: pbm
What exactly causes this to happen? Is it just that there are too few threads in the engine? Are these repairs permanent?
Aside from the too-few threads, the primary reason for launching a spark plug in a modular motor is people who think they don't need to use a torque wrench causing damage to the threads by over-tightening. The factory spec is 11 ft-lbs, no anti-seize.
 
My car did that about a year ago. It happened to my daughter. She drove the car home. I thought it was just a bad coil pack till I took the cover off and found the plug laying in there still attached. She drove 8 miles like that. I got it fixed. Relatively cheap, less than a $150. I changed oil I figure there was some fuel wash down. Other than that no issues. Runs good, uses no oil. That was a year ago. Ford made the fix painless.
 
This was the list from 2008. Doesn't seem that the 3v/4v 4.6L engines have the same issue. Not sure why not.

FORD:
1997 Thunderbird
1997-2004 Mustang
1997-2008 Crown Victoria
1997-1999 F-250 Light Duty
1997-2004 Expedition
1997-2008 E-Series, F-150
1998-2004 F-53 Motorhome Chassis, F-Super Duty
2001-2005 Excursion
2002-2006 Explorer
LINCOLN:
1997-2007 Town Car
1998-1999 Navigator
MERCURY:
1997 Cougar
1997-2008 Grand Marquis
2002-2006 Mountaineer

Some 1997-2008 vehicles equipped with a 4.6L 2V, 5.4L 2V, or 6.8L 2V engine and aluminum cylinder heads may experience a spark plug port with stripped or missing threads.
 
The 3V motors have a ton more threads and the spark plugs are interference fit. The 3V plugs until mid year 2007-2008 will break off in the head if you do not follow the removal procedure.
 
Originally Posted By: RF Overlord
Originally Posted By: pbm
What exactly causes this to happen? Is it just that there are too few threads in the engine? Are these repairs permanent?
Aside from the too-few threads, the primary reason for launching a spark plug in a modular motor is people who think they don't need to use a torque wrench causing damage to the threads by over-tightening. The factory spec is 11 ft-lbs, no anti-seize.


Finger tight, plus 1/8th turn with anti seize for me!
 
Originally Posted By: Colt45ws

There is a place advising using a very high torque value on the spark plugs to prevent them from loosening, but, Ive checked and the stock value of 10ftlbs is about all you want to give a 4-thread head. Taking into account the strength of the cast aluminium.
An 8 thread head is much better in that respect, and 18-22ft-lbs is doable. So, I did tighten the plugs on the F150 to 18ft-lbs.


The place you're referring to tested a head to 100lbs without ripping threads out- I think it'll handle 28lbs just fine. I've done several this way and ALL have felt rock solid.







Originally Posted By: RF Overlord
Originally Posted By: pbm
What exactly causes this to happen? Is it just that there are too few threads in the engine? Are these repairs permanent?
Aside from the too-few threads, the primary reason for launching a spark plug in a modular motor is people who think they don't need to use a torque wrench causing damage to the threads by over-tightening. The factory spec is 11 ft-lbs, no anti-seize.


Incorrect. The primary cause is under-torquing, in addition to too few threads.
 
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