Just When Things Were Going Good...

[Ross]

Well, I've posted recently about my new 4.10's and DR tune, and about how all was right with the world. I put in a new set of Bosch platinum plugs, just for the heck of it to try them out. Car was running fine. Headed to a friend's dad's funeral yesterday, and all of a sudden I hear the loudest popping and clanging and banging you can imagine. Car starts running rough, like there was a dead miss on one cylinder. Carefully drove it a couple of miles to where I could get it off of the freeway and look at it. Nothing visible was wrong, but something obviously was wrong internally.
Had it towed to a shop and this morning they call and tell me that the number 2 cylinder has backed the spark plug out and it has been banging around in there as I drove.
Discussed options, and decided to try a Heli Coil. Service guy says that it's not a 100% sure fix, but he's had about 80% success with not having to replace the head when using them. I guess we'll see.
I really can't figure this out. The plugs had been in less than a week. No, I didn't torque them, but I have never torqued a spark plug since I started putting them in back in the '60's. Never even heard of torquing plugs until I joined this board. This is the third set of plugs I've had in the car, and this is the first problem like this.
Service guy said that they have seen a lot of problems with Bosch plugs. Said that they are just plain cheap, regardless of how much they cost. OK, if this is my fault and I just didn't put the plug in tight enough, then I have to take the blame. But I swear I can't figure out how I put that plug in any different than any other one.
My hopes for long engine life are quickly disappearing.

[FordNut]

No, I didn't torque them, but I have never torqued a spark plug since I started putting them in back in the '60's. Never even heard of torquing plugs until I joined this board.
The Marauder is the first car I've ever torqued the plugs in, too. But I know how expensive aluminum heads are (the labor's outrageous too) and I've read enough about problems with threads stripping out of Lightning heads that I feel better being safe than sorry. Always torque them and there's no question whether they were installed right.


Sorry for your misfortune, hope the helicoil works for you.

[Rider90]

I had a couple plugs pop out of my 4.6L SOHC in the Vic. We used brass inserts, forgot the name of them, but they were widely known and used. Stay away from BOSCH everything, I've used their plugs and wires before and never will again. Even their really nice expensive plugs don't last long.

[Marauderman]

The Marauder is the first car I've ever torqued the plugs in, too. But I know how expensive aluminum heads are (the labor's outrageous too) and I've read enough about problems with threads stripping out of Lightning heads that I feel better being safe than sorry. Always torque them and there's no question whether they were installed right.


Sorry for your misfortune, hope the helicoil works for you.
So.....Brian.........tell us again the torque spec again for them...thanks.......

[Breadfan]

The torque value for spark plugs on our cars is 12ft/lbs.

I used anti-seize compound too. Part of the problem is fatigueing the threads when you pull out the old plugs. I want to minimize that in the future. I've read of some bring the threads out with the plug. EEK! Scary stuff. Also, some will claim the plugs ground to your heads to spark and that anti-seize will cause problems - antiseize is made of micronized metal particles in a suspension, and the suspension burns off leaving a micronzied bit behind that keeps things from corroding and seizing. I've never seen this cause a problem.

BTW, DO NOT confuse anti-seize compound with anything like LocTite or Thread Locker. These products are ADHESIVES that keep bolts locked in threads and is definitely not what you want. I only bring this up because I've seen people use these terms somewhat interchangeably.

During my Trilogy install I think the scariest part for me was doing the plugs after the horror stories I had heard. I took my time, slowly broke the OEM's loose, and used anti-sieze and torques to 12ft/lbs on the new ones.

A good idea is to recheck the torque after a few miles too.

I've been torquing spark plugs for a long time - probably didn't have to but always torque them to 10-15 ft/lbs depending on the car.

I have a tendecny to overtighten that's why I do this. When I was younger I snapped a spark plug in half on a lawn mower engine. :)

I'm very sorry to hear about your misfortunes though - I have heard the helicoils seem to work well for most. If you're under warranty you can try to take it to the dealer, you're not the first or the last to have this issue.

[FordNut]

I believe the spec is given in fig newtons or inch-lb, but I always go with 10 ft-lb and it's in proper range. Plus that's the lowest setting on my torque wrench.

[EbonyMarauder03]

We have a MM at my dealership with a plug or two blown out of the driver's side head. Ford has a TSB or FSA about using non-Ford plugs in the DOHC V-8's. As a matter of fact I think this guy had Bosch plugs in his car. His head should be in tomorrow. Ford does NOT recommend heli-coils since they affect heat transfer from the plug to the head.

[Smokie]

I believe the spec is given in fig newtons...

Fig Newtons, now that's funny.:D

[Breadfan]

I believe the spec is given in fig newtons or inch-lb, but I always go with 10 ft-lb and it's in proper range. Plus that's the lowest setting on my torque wrench.

Haha fig newtons. :)

I've heard anything from 10-12 for our cars, I err on the side of tight since some people had them backout.

[Zack]

Torque wrenches suck!

[TripleTransAm]

Torque wrenches suck!


Sez the guy with warped brakes.

:lol:

[Vortech347]

Are the plugs in our cars Full length? The plugs in the Aluminum heads on my stang have twice as much thread as the stock head plugs did.

[RoyLPita]

Checkout Dave Compson's thread about this subject. It will be helpful.

[Ross]

Thanks for all of the responses. I always use a little anti seize on the plug threads. As far as Ford not recommending heli coils, I suppose they simply prefer that we buy new heads from them! Of course, if the heli coil doesn't work, I may have to do that, anyway...
Answer this for me, though.
If you have changed your plugs in the MM, you know that there is a long hole that the plug goes down into. After the plug is installed, a long rubber (plastic, silicone, etc.) boot goes over the plug to make the connection, and the coil is on top of the boot. All of that is held down tightly by the coil cover.
I could see all of this backing out if the coil cover wasn't in place, but with the cover holding everything down, how could a plug pop out and have anyplace to go? Seems like the simple pressure of everything pressing down on it would hold it in place?

[jakdad]

Ford OHC 4.6 & 5.4 engines have been launching plugs since day one. The early 5.4s had about 3.5 threads holding plugs. Later ,2001, I believe were redesigned with about 8 threads. Most of the time the plugs wouldn't launch until you stressed them (such as racing). Don't expect Ford to issue a recall on the millions of heads. I thought they would have corrected this on the 4 cam motor. Maybe not. Maybe DR can chime in on this since he has been into a lot of 4 cam engines.
:mad: :mad:

[fastblackmerc]

Thanks for all of the responses. I always use a little anti seize on the plug threads. As far as Ford not recommending heli coils, I suppose they simply prefer that we buy new heads from them! Of course, if the heli coil doesn't work, I may have to do that, anyway...
Answer this for me, though.
If you have changed your plugs in the MM, you know that there is a long hole that the plug goes down into. After the plug is installed, a long rubber (plastic, silicone, etc.) boot goes over the plug to make the connection, and the coil is on top of the boot. All of that is held down tightly by the coil cover.
I could see all of this backing out if the coil cover wasn't in place, but with the cover holding everything down, how could a plug pop out and have anyplace to go? Seems like the simple pressure of everything pressing down on it would hold it in place?
Have you looked at the spring that connects the coil to the plug? It looks like a giant ball point pen spring. Here are some pic of the OEM spring & the GMS replacement that Wes did a group buy on. OEM on the top, GMS on the bottom. The GMS is braided wire that you can not bend easily.

[FordNut]

Thanks for all of the responses. I always use a little anti seize on the plug threads. As far as Ford not recommending heli coils, I suppose they simply prefer that we buy new heads from them! Of course, if the heli coil doesn't work, I may have to do that, anyway...

Well, there is a possibility the reduced heat transfer efficiency would cause the plug to run hotter. For a N/A car, the additional heat probably won't be an issue but I could see it being a possible source of detonation in a S/C car.

[wchain]

Bosch Plugs are a BIG mistake. Motorcrafts are the way to go. There's Bosch Germany, and Bosch USA, two different qualities. When I work on GM cars, they get AC Delcos, Jap cars get Jap Plugs, and Fords get Motorcrafts. They're $2.19 bucks at you local McParts

The repair shop doesnt make sense Ross.
The #2 plug backed itself out, okay, so whats clanging and banging around? Theres nothing to clang and bang. Compression is lost through the hole that the plug was backed out of and pushing against the plug that is secured with the COP.

If thats the case, you dont even need a heli coil. Just put a new plug in and keep going.

What likely happened, and this has happened to Bosch Platinums I used before, is that the side electrode, as well as the center electrode, insulator tip AND seal, all fell off the plug itself, and is banging and slapping inside your cylinder walls.
http://images16.fotki.com/v277/photos/4/41821/223357/Plug_construction-vi.jpg
Now the 3rd case, that would call for a heli coil, a TIME Insert (http://www.timesert.com/index.html), or a replacement head, is if the plug was launched from the head, along with the threads themselves.

The last 2 reasons are probably more plasible than the first answer. I hope the info you're getting is not from Southwest Lincoln Mercury. Is this shop a reputable place? How much experience do they have with 4V/Ford Mod Motors

Here's another thread I started about plugs blowing out.
http://www.mercurymarauder.net/forums/showthread.php?t=20586

[Dave Compson]

http://www.mercurymarauder.net/forums/showthread.php?t=19779&highlight=spark+plug+head

Now what do i do. stripped plug in head. Too me a sec. to do the search, but here it is. Good luck. Been there, dont want to go there again. Its motorcraft plugs for me from now on!

Dave

[JACook]

Discussed options, and decided to try a Heli Coil. Service guy says that it's not a 100% sure fix, but he's had about 80% success with not having to replace the head when using them. I guess we'll see.
I do hope he was using the "helicoil" term in the generic sense. Helicoils are not the best repair for Mod Motor
spark plug holes. I use TimeSerts (http://www.timesert.com/html/ford_sparkplug_faq.html). <-Link These restore both the threads and the tapered seat. And, unlike
Helicoils, these will never back out. Read how they work, and you'll understand why.

As for the torque wrench thing, I've had some people question my ancestry over this, but having done a few
of these repairs on Modulars, I can say yours is not an uncommon experience. The factory calls for ~12 ft/lb
and they mean it. As spark plugs go, this is not all that tight.