Advice on what to do about a technician who stripped my spark plugs into the head

[KrisZ]

It’s not just an insert job, the threaded portion for two of the spark plugs is probably stuck in the cylinder head, since it’s missing from the plugs.

Not sure if another tech would’ve done any better, likely not.

 

[Rand]

What lube is usually put on the the tap/cutter when doing this?
Blow it out? So, after the repair, leave the plug out & crank it?
Vacuuming the cylinder won't help?

usually a heavy grease it will hold most of the shavings.. if done correctly.
of course if having to do 3 cylinders.. and its a I-4 engine it might be easier to do with head off.
How much is a replacement head?

 

[Nukeman7]

Can you help clarify the situation? Did the mechanic damage the cylinder head during spark plug removal?

Or did he install the spark plugs and over torque them and strip out the threads in the head?

Or did he cross thread 3 out of 4 of them?

If it happened during removal, there may not be much one can do about that. Sometimes problems happen and there is no magic work around.

Here is the Original BITOG thread from last year that explains the background of the OP's situation. Note that only one cylinder is stripped while the other two have plugs that fractured, leaving the metal base of the plug stuck in the cylinder head. The stuck remnants may (or may not) be extracted without damaging the threads.

The video below shows how a Time-Sert kit is used to repair stripped spark plug threads on a motorcycle engine without pulling the cylinder head.

 

[Mechanician]

Okay, thank you for letting me know. What do you think the mechanic should have done in this situation?

And I'm guessing the Time-sert repair inserts would still be a pretty expensive job that requires removing the head?

You do have more problems than just damaged threads.
The head will have to come off. The two broken pieces need to be removed - and they're not made of aluminum.
These were NGK plugs, look original, they should have been changed at 105,000. They may have come out back then - no way to know.
I do agree with others that he should have stopped after the first one. He should have given you a call.
This was a common problem on the very old air cooled VW Beetles. There were some old tricks for those, but those tricks probably couldn't be used today.

 

[Mechanician]

The video below shows how a Time-Sert kit is used to repair stripped spark plug threads on a motorcycle engine without pulling the cylinder head.

I have done a few, and have seen many done by others without removing the head.
Care has to be taken - to remove as much of the shavings as possible.
I have never seen any destroyed engines. The engines don't seem to mind the little soft aluminum shavings that are left behind.

 

[Mackelroy]

I dont know the effects natural gas would have on aluminum head and spark plug corrosion wise.

In Hind sight, maybe he should have just declined the whole job, dealing with grandpas old modified vehicle.

Anyway, you dont really know any method he tried, but you have a stripped head, and your perception is all his fault that he could have avoided. True or not true.

You either tow it somewhere else, or let them give you an estimate for repair.

 

[Exhaustgases]

Using a penetrate oil before removing them ? That will only come close to working if the spark plugs will loosen a small amount first.
In this case it is not the mechanics fault. No matter who tried to remove them, they would have done the same thing.
This is the glory of aluminum heads for one. If it had the time serts this would not happen.

Oh any smart shop should have a clause saying that this sort of thing can happen, and if it does we are not at fault and have you sign it.

 

[Exhaustgases]

Anyone saying a simple spark plug change out is easy and fast, think again. It can be one of the more difficult jobs to do. Just look at that mess. Can go from a couple hundred dollar job to a 3000 one quick.

 

[KrisZ]

I’m pretty sure these plugs could’ve been worked back and forth little, by little and removed without damaging the threads.
However this requires experience to recognize there is a problem. Something that’s lacking in the industry.

Looking at OPs spark plugs, the tech likely just kept turning the wrench despite the resistance. He was so confident in his skills, that he repeated the process two more times. The carnage is quite an obvious sign of his lack of experience.

 

[JHZR2]

Anyone saying a simple spark plug change out is easy and fast, think again. It can be one of the more difficult jobs to do. Just look at that mess. Can go from a couple hundred dollar job to a 3000 one quick.

Sure, if you yank out very old plugs the way it happened to op….

A little care and they will usually come out. As others said, if you have issues with the first, you stop and re-assess.

It’s not like this is an engine wedged in a tight bay or some huge exotic thing. This is four plugs in an inline engine…

 

[meep]

Man that’s rough. Dude. So many good points already. Theres not a small chance that even with an experienced tech there would have been some damage. This guy didn’t have the best judgment but the one plug with threads looks pretty welded in there. THAT wasn’t his fault. Do these CNG cars run hot?

 

[D60]

Okay, thank you for letting me know. What do you think the mechanic should have done in this situation?

And I'm guessing the Time-sert repair inserts would still be a pretty expensive job that requires removing the head?

In your original thread which Nukeman links @Trav explains what they should have done.

I was also going to look for that thread because I remember this discussion

 

[IndyIan]

I’m pretty sure these plugs could’ve been worked back and forth little, by little and removed without damaging the threads.
However this requires experience to recognize there is a problem. Looking at OPs spark plugs, the tech likely just kept turning the wrench despite the resistance. And we see the carnage.

Yeah, maybe... I've never had sparkplug corrode and stick like that, but I have on bike pedals with an aluminum crank arm and steel pedal shaft. The aluminum or iron oxide just stuck in some of the steel threads of the pedal and carved out the aluminum threads on the way out. I had never seen that before, but it seemed to me the oxide was so hard and stuck, that it wasn't popping loose, and the aluminum is just too weak.
If it was steel into steel, I'd do some calibrated smashing with a hammer to break the corrosion lock, but into aluminum I don't think that works?
The sad thing is, that the gap on the one plug looks a bit big but probably fine, and the OP was right in thinking that all 4 plugs aren't going to fail at once.... I have one local mechanic that I think would do the same thing though, just stubbornly follow the book even though its likely to cause bigger problems, and costs for the customer... Needless to say I only went to him once and haven't been back.

 

[clinebarger]

You approved having the spark plugs removed.....Your chances of ever seeing money out of that shop is slim to none.

The head will need to come off & have at least the 2 broken plug core drilled out on a Milling machine, Might as well insert all 4 holes.
I don't like having a steel insert protruding into the combustion chamber....A good machinist can install shorter inserts & not drill all the way through.

 

[Cujet]

Just an FYI, inserts can be just fine. Aircraft cylinders use inserts right from the factory.

 

[The Critic]

That wasn't the tech's fault. Plugs were seized in the head. Change your plugs on time - every 105K or 7-10 years. Cylinder head will need to come off in order to properly repair this.

 

[Nukeman7]

That wasn't the tech's fault. Plugs were seized in the head. Change your plugs on time - every 105K or 7-10 years. Cylinder head will need to come off in order to properly repair this.

This appears to be a common issue with the Civic GX due to the natural gas engine running hotter and causing the plugs to seize. This CNG forum thread has a lot of discussion on this topic.

 

[BrianF]

We ran into issues with our old propane vehicles. Everything ran dry and tricky to remove. Our old factory propane van ate valves.

 

[dan7055]

Hey all, can you advise me how difficult it might be to remove the cylinder head myself, then take it to have it repaired? How much do you think it should reasonably cost to have the cylinder head repaired once removed?

 

[notharry]

Who really knows what could have been done differant. Many trusted videos i have watched on the fords that broke plugs said crack them and soak them with penertating oil. work them a bit afterwards. Sometimes it worked sometimes not and broke. Some say the engine should be hot others cold. Some say heat the engine up by running it under load spray with peratrant crack them and add more. Wait for it to cool and work the fluid down intl the threads. Work them back and forth (which makes the mose sense to me). Some say after that use a impact because once the plug is moving, keep it moving. And that sort of clicks as well.

Ford had a kit that replaced the threads in the engine. IF there is any debris other than aluminum left in the cylander (aka if a spark plug part needs to be drilled out) pull the heads. The steel shaving will quickly cut into a piston and ruin it, the bore and the engine probably. Aluminum will mostly vaccume out blow out wipe out. take your time blow and vacumme before moving rotating the engine at all. The piston shold be midway in the bore. when cutting ned insert threads clean then lower the piston all the way in the bore. Clean again. IF any part of the broken plug is still in the head it can be soaked and may come out with a easy out. First.. Get this to a competant mechanic. He has to back the repair. If he says pull the head pull the head. Do it right and perhaps just install a good used head and check the valves, lap them in to make this a lasting repair.

The first shop that touched it should have some skin in the game in that he should not be paid a dime and perhaps help with the repair. A Small claims suit may be fruitful but IMHO, these things can happen but most will agree nearly never this bad. I would be at least you would get every dime you paid him back. Getting one shop to testify against another will almost never happen.

Not many answers from me Just more questions sorry. For what its worth My 2 cents.

Good luck