Spark Plug shot out of head

[wesman]

My mechanic just called me, I have a spark plug on the passenger side that has shot out of the head.
I was driving along (not fast at all) and I heard a pop and then it started missing badly.
Ouch.

[RR|Suki]

My mechanic just called me, I have a spark plug on the passenger side that has shot out of the head.
I was driving along (not fast at all) and I heard a pop and then it started missing badly.
Ouch.

oh dear... that's no good. Good to see you are posting again, do you still run G-Man track days? I plan on doing track days next season, so if you ever do Road America again, me and the racing club here at MSU would love to invade :D

[magindat]

#2?

This issue has been discussed a million times all over the net.

Will they be able to helicoil? Or, do you need a new head?

Good luck.

BTW, have your plugs ever been changed?

[RoyLPita]

Check out Dave Compson's thread about his ordeal.

[AstroVic]

I had the same thing happen on the #7 cylinder of my 2000 CVPI. It has a brand new engine now, so it's no biggie.

Unfortunately, this is not uncommon. :(

[ckadiddle]

That sucks. Sorry to hear it.

[grampaws]

Sorry to hear..common problem though..
There is a company called the Plug Doctor
I think located in Hamilton,It's scary a guy makes
a career fixing these!! really expensive but does
good work-no come backs!!
expect 500 too 800 bucks ball park..aaargh!

[Mach1]

Sorry to hear this. I have first hand experience with this. My F150 5.4 did the same thing. When changing spark plugs in these engines you have to be very careful. When the truck reached 100,000 miles, I decided to change the spark plugs. The number 6 plug is located right below some sort of fuel rail check valve or something, and I couldn't tighten it very well without removing the fuel rail, I took a chance and thought I had it tight enough. The engine started making a ticking noise shortly after I changed the plugs but I thought it was valve lifter noise or something. The ticking got louder as time went by and the plug blew out about 20,000 miles after the plug change! If only I had checked out the plugs. I changed the head myself and it only cost me about $500.00 in parts. I learned the hard way you have to be very careful when changing plugs in these engines. It turned out ok in the long run, now the truck has almost 250,000 miles and is still running great. There is a tool available from a company called Powerbuilt, its called the Backtap, it sells for $39.95. I doubt it would work in your engine but if you still have some threads left it may be worth trying.

[Mach1]

So if you hear any ticking from your engines, I strongly recommend you check the spark plugs!!!:nono:

[MM2004]

My mechanic just called me, I have a spark plug on the passenger side that has shot out of the head.
I was driving along (not fast at all) and I heard a pop and then it started missing badly.
Ouch.

Are the threads damaged/stripped?

Mike.

[wesman]

Thanks for the support guys. The car had Densos in it from Denis Reinhart pretty soon after I got it, maybe 45,000 miles now. The threads are gone. I am pretty sure he said its the #3 cylinder. No doubt my car has had a hard life, when its not on a track its towing my race car!
Wes.

[Breadfan]

If you try to repair I recommend timeserts vs a helicoil: http://www.timesert.com/

At this stage in the game getting a replacement used head probably will be similar in price, but may be more labor which could drive the overall cost up.

Good luck

[Bradley G]

That's too bad, Wes.

Do these plugs, vibrate loose?

[Rider90]

That's too bad, Wes.

Do these plugs, vibrate loose?
I've had this happen to me on my 99 CVPI with about 102k on the clock. I was driving home and heard a pop, then a misfire and a lot of passing air under the hood. Sounded like the exhaust manifold cracked in about 20 places at the same cylinder.

They don't vibrate loose, but rather the thread count is a joke. I don't recall specifics, but because the aluminum heats up, cools down, expands, and contracts more than cast iron there is more risk involved. I'm shocked to hear our Marauders can fall victim to this, I was hoping it had been taken care of by now.

[FordNut]

Some claim it's caused by over-tightening, others say it's from leaving them too loose, there's even claims that it's due to thread galling. That's why I always use a torque wrench and just a touch of anti-seize.

[Marauderjack]

Another reason to get the Granatelli solid connectors......THE PLUGS CAN'T BACK OUT!!!:beer:

Marauderjack:D

[RF Overlord]

Some claim it's caused by over-tightening, others say it's from leaving them too loose, there's even claims that it's due to thread galling. That's why I always use a torque wrench and just a touch of anti-seize.Actually, all three can contribute to the problem. Over-tightening easily can damage the threads without your being aware of it, under-tightening is obvious (especially with so few threads) and thread-galling can be caused by too many installation/removal cycles and/or using a spark plug with the wrong finish.

Some will claim they can "feel" when a plug is properly tightened without using a torque wrench. The FSM specifies 7-15 ft/lbs; this is a very small range to repeatedly, and accurately, obtain on all 8 plugs using only a ratchet. While it may have been acceptable practise on the cast iron heads of yesterday, one should ALWAYS use a torque wrench on aluminium heads. Use of anti-seize very sparingly is a good idea, but only if the torque reading on the wrench is properly compensated for (lowered about 10%).

[wesman]

Want to know something funny? I was getting ready for a trackday 400kms away & planning on towing with the Marauder when this happened. Instead I parked it at my Mom's house and we towed with her 2005 Explorer. By the time I got back, I had had enough of the Explorer experience. I get back in my car to take it to the shop, cold as hell, missing badly, 70% of normal power & smelling like gas, and I still loved it right away. Strange. I guess I bought the right car.

We are going to try an insert that is tapered. If that doesn't work a fellow board member has offered to sell me a set of used heads.
Thanks for all your support Gents.

[RoyLPita]

Keep us posted, please.

[grampaws]

The plugs usually recommended are full thread..for max thread contact
replace your existing plugs with full thread plugs..especially the
one that is repaired..It is repairable the time serts look like a good
method--the hard part is not dropping al the shavings into the cylinder..

[Mach1]

It would be interesting to know if any factory installed plugs came loose. I have a feeling that many of the blow out problems are caused by installing replacements incorrectly. You must blow out the spark plug pockets with compressed air before removing the plugs, there can be quite a bit of road grime and sand in them, and if you don't clean it out, dirt and sand will wedge between the plug seat and head seat. If this happens, the plug will leak slightly and erode, then become loose, rattling around until it wears the threads off! Installed properly, they don't cause any problem. They are pretty fussy though.

[Mach1]

I guess my main point is if the plugs are seated and torqued properly, you won't have any problems. Also, the leakage past the plug is what causes the tick noise, not the plug rattling. My coil assembly looked like charcoal underneath, from all the hot combustion gasses escaping past the plug. I wonder how many of these problems are caused by dealers service techs installing them improperly?

[Big House]

Well when I get my plugs replaced.. the Stealership will do the work. That way if something goes wrong...they will replace what they screw up.

[Shora]

Well when I get my plugs replaced.. the Stealership will do the work. That way if something goes wrong...they will replace what they screw up.

The problem may likely occur in as much as 20,000 miles. Good luck getting the dealership to take responsibility then.

Oh, and my dealership is so afraid to touch the spark plugs that they begged me to wait until 100,000 miles. Why you ask? So that my ESP will expire and save them the expense if something goes wrong.

[JACook]

The plugs usually recommended are full thread..for max thread contact
replace your existing plugs with full thread plugs..especially the
one that is repaired..It is repairable the time serts look like a good
method--the hard part is not dropping al the shavings into the cylinder..

Fully-threaded plugs will do absolutely no good, unless the heads have been retrofitted with the fully
threaded type of TimeSerts. The plugs aren't the problem. The heads themselves only have about six
threads engaging the spark plugs. And really, this isn't a problem either, as long as proper service
procedures are being followed.

RF is spot-on with his recommendation. I've been chastised once or twice on this board, for being so
anal about torquing spark plugs. All's I can say is, you pays your money and you takes your chances.
An inch/lb torque wrench is cheap insurance when you think about it.

The TimeSerts are an excellent repair method. I've done several, and highly recommend them. The
repaired hole completely replaces the threads and tapered seat, and the locking tang ensures they
can never back out.

[Marauderjack]

JACook....

What do you do with the shavings from tapping the hole for the TimeSerts....It seems to me they would go directly into the combustion chambers??:eek:

If there is a way to install them without ill effects of aluminum shavings in the cylinders why not just do all eight holes and forget about it??:confused:

I have changed the plugs in my car five or six times and have no issues with the threads and no.....I don't torque them!! I have installed plugs in aluminum heads for 40+ years and although the torque wrench is a good idea I have never used one!!:shake:

Marauderjack:cool:

[Hotrauder]

JACook....

What do you do with the shavings from tapping the hole for the TimeSerts....It seems to me they would go directly into the combustion chambers??:eek:

If there is a way to install them without ill effects of aluminum shavings in the cylinders why not just do all eight holes and forget about it??:confused:

I have changed the plugs in my car five or six times and have no issues with the threads and no.....I don't torque them!! I have installed plugs in aluminum heads for 40+ years and although the torque wrench is a good idea I have never used one!!:shake:

Marauderjack:cool:

Jack, What is the old saw about lucky and good? You are both, my friend. I know that you don't advocate rookies like me install without a touque wrench just to make that clear, right? thanks Dennis

[JACook]

What do you do with the shavings from tapping the hole for the TimeSerts....It seems to me they would go directly into the combustion chambers??:eek:

I do three things.

First, the cutting tools are coated with wheel bearing grease, which catches the majority of any
chips. The cutter is stepped, and made with fairly deep v-shaped grooves between the cutting edges.

Second, I go slow. Pull, clean, and regrease the cutter frequently, and vacuum out the spark plug
hole using a long skinny (bout 5/8" dia) nozzle I bought at Home Depot.

Third, I position the engine so that the exhaust valves are slightly open, and attach a shop vac so that
it blows air into the tail pipe. On cars with dual exhaust and crossover tube, I duct-tape an old sock in
the other tail pipe. This provides a continuous stream of air out the spark plug hole while I'm cutting.

I won't say it's perfect, but since it _is_ small aluminum chips we're talking about, I'm comfortable that
there won't be enough chips missed to make a difference.

The cutting tools do not have to cut all that deep either. The spark plug hole is already mostly there.
The biggest cut happens at the top of the hole, where the insert will seat.



If there is a way to install them without ill effects of aluminum shavings in the cylinders why not just do all eight holes and forget about it??:confused:

Some people advocate doing exactly what you suggest. I don't, mainly because if the other holes are
not damaged, proper torquing is an easier and cheaper way to prevent future problems. I do pull all the
other plugs and examine them and the holes they came from.


I have changed the plugs in my car five or six times and have no issues with the threads and no.....I don't torque them!! I have installed plugs in aluminum heads for 40+ years and although the torque wrench is a good idea I have never used one!!:shake:

And yet, here we are.
We're having this discussion precisely because someone else thought exactly the same thing, no?

Like I said, you pays yer money and you takes yer chances. I haven't been doing this stuff for quite 40
years, but getting close. I didn't used to use a torque wrench on 'em either. But think about the plug
holes in most older aluminum heads. The ones on my '71 Datsun have 3/4" of threads. The greatest risk
to these threads is galling when you're removing the old plugs. They're also washer-seat plugs. At the
other end of the spectrum are the old VWs. Used to do a lot of inserts on those. But again, it was
usually because the old plugs came out with aluminum strands wrapped around their threads.

The Ford Modular engines, OTOH, only have ~6 threads engaging the spark plug, and they're taper seat.
Could I install them using my calibrated bare mitts? Probably. Knowing what I know about these heads,
will I? Not a chance. Just not worth the risk.

[Ross]

Welcome to the club. Mine did that about 20,000 miles ago. Really sucks. That's why I say that this is my first and last Ford. Never had a GM engine self destruct. OK, flame away. This has brought up really bad memories.

[wesman]

Got it fixed, $800 Cdn , we used a helicoil. There was enough material to tap new threads. There was a destroyed coil pack too.