Stripped Spark plug hole....or worse?

SmokinBBC

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Driving to work today and a loud bang happens under the hood of my Ford Expedition. Pulled over with the engine still running to take a look. Sounded like a blown exhaust gasket(or like the sound of backfiring through the exhaust). Drove it home.

Coil is blown off and spark plug is laying next to the valve cover. It's a Triton V8 which has a coil at each cylinder. I threaded the plug back in only to find that the plug hole is stripped. As Gene would say...Mutha Fu....


It's a 2003 and the engine has 130k miles on it. The plugs were changed at 100k. It ran great until today. What would cause this to happen? Maybe the plug hole was stripped when the mechanic replaced the plugs and it just now gave way?


What options do I have with this? Heli coil? New head? If anyone has one of these engines in an expedition, you know it is almost impossible to do work on the 4 rear cylinders since half the engine is under the front of the cab. I was going to call the local dealer to find out what they could do, but I wanted to check here first.

Just ain't my day!
 
Effed without benefit of intercourse.....aluminum heads are SO easy to cross thread on spark plugs...sounds like the mechanic did that, but good assed freeking LUCK proving that.....

ME, assuming they deny forever, pull engine, pull both heads, take to a head shop, .....nothing else to do, unless your last name is Trump....

:bomb::goodnight:
 
My buddy just had this same problem on his E-250, back plug blew out. It took the shop most of the day to get the thing repaired but I don't think the hole was stripped on that one, the plug core blew out of the insulator. It is a major PITA to work on. No room!

I'd try the heli-coil insert first, that is if you can get in there.
 
There's absolutely no room to get a drill in there for a helicoil repair.

The only way to get at it is to pull the head.:mad:
 
There's absolutely no room to get a drill in there for a helicoil repair.

The only way to get at it is to pull the head.:mad:

I know your bummed, and expectedly so, but you already know the answer. Pull the head, and take it to a cylinder head shop.
 
There is a kit made specificly to repair your problem without removing the head. We have a fleet of over 100 Crown Vic patrol cars with the 4.6 and have repaired many of those blown spark plug threads, it's a fairly common thing with the 4.6's and the 5.4's.

NAPA auto parts stores sell the kits.
 
That's great to know. There you go again, the power of the forum is awesome! I have one of these 4.6's in my E-250 and I'll be filing this one away for future reference. Thanks!

So what's the problem with these heads, do they run that hot at the back that this happens?
 
There is a kit made specificly to repair your problem without removing the head. We have a fleet of over 100 Crown Vic patrol cars with the 4.6 and have repaired many of those blown spark plug threads, it's a fairly common thing with the 4.6's and the 5.4's.

NAPA auto parts stores sell the kits.

On a transverse mount engine on the firewall side?
 
All of the vehicles in our fleet with the 4.6 and 5.4 are all rear wheel or 4 wheel drive. I'm not aware of any Ford product with a traverse mount 4.6 or 5.4 engine.
 
Talked to the service mgr. at the local ford dealer on Friday. He said it's fairly common and fixes them without taking the head off. He did not say the specific cause, but said it was possible that the thread was stripped when the plugs were change.

Fordman, how do you get all the metal shavings and the helicoil tab out of the cylinder? I am concerned that any of that stuff left behind would score the walls and damage the rings or get lodged between the valves and seats.

Even though this engine has 130k on it, it doesn't burn any oil. And apparently the cylinder pressure is fine...spark plug shooting out kinda proves that. I am wondering if the cats are bad or if there is blockage in the exhaust system. Would that cause excessive back pressure which could contribute to the thread failure and plug blowing out? Cats/exhaust system are original.
 
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This is a very common prob on those tritons, do a search on youtube, you'll see several vids where these are repaired in the vehicle. Apparently it's shitty head quality that causes these problems. The fix is to install a threaded insert. (timesert)
 
There is a kit made specificly to repair your problem without removing the head. We have a fleet of over 100 Crown Vic patrol cars with the 4.6 and have repaired many of those blown spark plug threads, it's a fairly common thing with the 4.6's and the 5.4's.

NAPA auto parts stores sell the kits.

My bad. I had some serious ASSUMING going on.
 
This is a very common prob on those tritons, do a search on youtube, you'll see several vids where these are repaired in the vehicle. Apparently it's shitty head quality that causes these problems. The fix is to install a threaded insert. (timesert)

Thanks TT. Found a couple of good ones that explain it well.

[ame]http://www.youtube.com/watch?v=2opNGDKGdkQ[/ame]
 
Our kit doesn't have the tab you knock out like a Helicoil does. It uses a Keensert type of threaded insert that has 4 locking tangs down the side of the insert. You drive them down with the tool in the kit and it locks the insert into the head.

Once done we stick a vacuum adapter in the hole with a sealing plug on the end and suck out any shavings. Then a quick look with a borescope to make sure it's clean is the last step.

We haven't had to replace any threaded inserts on any 2006 on up engines. The 2005 and down seem to have had the problem. Our kit cost 600.00 but it gets used fairly frequently. NAPA auto stores have a version for the do it yourself type of person that's not as extensive or expensive as the one in the shop.

If you were having catalytic problems the OBD II on board system would detect it and turn on the check engine light. Speaking of, did this turn on the light and the misfire on cylinder # code come up?

130K on your engine is no big deal, it's in the prime. Our patrol cars go out of service at that mileage and at 130K, our engines have over 200K on them with all of the idling time added in. The trannys may be shot but the 4.6's still run great.
 
There were some recalls on that issue. Your vehicle is probable past that but I would ask the question of the Ford service manager.
 
Our kit doesn't have the tab you knock out like a Helicoil does. It uses a Keensert type of threaded insert that has 4 locking tangs down the side of the insert. You drive them down with the tool in the kit and it locks the insert into the head.

Once done we stick a vacuum adapter in the hole with a sealing plug on the end and suck out any shavings. Then a quick look with a borescope to make sure it's clean is the last step.

We haven't had to replace any threaded inserts on any 2006 on up engines. The 2005 and down seem to have had the problem. Our kit cost 600.00 but it gets used fairly frequently. NAPA auto stores have a version for the do it yourself type of person that's not as extensive or expensive as the one in the shop.

If you were having catalytic problems the OBD II on board system would detect it and turn on the check engine light. Speaking of, did this turn on the light and the misfire on cylinder # code come up?

130K on your engine is no big deal, it's in the prime. Our patrol cars go out of service at that mileage and at 130K, our engines have over 200K on them with all of the idling time added in. The trannys may be shot but the 4.6's still run great.

The service engine light had a slow flash after it happened, but no codes in the system. When I cranked it on Friday to get it turned around in the driveway, no flashing....strange.
 
So what's the problem with these heads, do they run that hot at the back that this happens?

Apparantly there is only 2 or 3 threads for the plugs. So when a defect like that causes problems some manufacturers will be a bit more foregiving if you yell loud enough or know someone. One of those warranty deals that they try not to talk about. Let us know if you have success.
 
So what's the problem with these heads, do they run that hot at the back that this happens?

Apparantly there is only 2 or 3 threads for the plugs. So when a defect like that causes problems some manufacturers will be a bit more foregiving if you yell loud enough or know someone. One of those warranty deals that they try not to talk about. Let us know if you have success.

The plug turned about 4 times before finger tight.

Since it is my DD which I needed up and running....and I have never done this before, I had it done at the dealer.

$280 for the labor. Coil, plug and thread insert were extra. (OE prices.) Car runs as it did before....knock on wood!

BTW, the dealer was pretty busy in both the service area and on the SALES floor.
 
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