Spark plug broke?

[ImBravo]

Took a car into 1st mechanic for cylinder 2 misfire after i had already change all 4 plugs. They said that cylinder 3s plug was “cross threaded” and that was causing the misfire on cylinder 2 so they replaced the spark plug.. made no sense to me.. so i get the car back and take it on a 60mile drive and back and it breaks down again on the way back but this time much worse. Barely made it home and made a call to a new mechanic to get a 2nd look at it.. well it sat for about a month before i could get it in but when i did, they said that what happened during my 60mile drive was that the “new” plug they put in cylinder 3 broke and fell into the cylinder and did some pretty good damage inside and that he recommends a full engine replacement.. but he said i should talk to the original mechanic shop and see what they will do about their mistake because new plugs dont just break and it looks like it they put in an old plug instead.. the original shop said bring it in monday so they can take a look at the damage.. but they didnt seem to happy with me.. whats the likelihood they actually help me out? Attached is a pic of the plug that we pulled out.. (still fired btw but not sure how)

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[cerbomark]

wow, never heard such a mishap. Wonder how they got a new plug in after the old one was cross threaded. you think a new plug won t be possible to just screw in. good luck.

 

[NGOT8R]

I wish you the best of luck in getting this resolved from the first mechanic.

The problem I see here is, the first mechanic told you that the spark plug was cross threaded, but what I don’t understand is, why did they work on the car with a cross threaded plug without removing the head? There Is no mention of how the mechanic repaired the cross threaded spark plug hole, although in your photo, it does appear that someone installed a new insert in that hole and then threaded in a new plug which ultimately broke.

That begs another question. If a new insert was installed, did the mechanic seat the insert too low and as a result, the piston hit the plug and caused it to break off in the cylinder, thus causing catastrophic damage? Unfortunately, I don’t see you getting out of this situation without paying something out of pocket for it.

IMO, the right thing to do here, may be for the first mechanic to meet you in the middle on the cost, since he said the plug was already cross threaded, which necessitated the need for that repair in the first place. With that being said, whomever cross threaded the plug has culpability there and if the first mechanic made a mistake by improperly installing a new insert that severely damaged the engine, then he too is culpable. That’s why I say meeting in the middle on the cost to repair it seems fair to me.

 

[ImBravo]

I wish you the best of luck in getting this resolved from the first mechanic.

The problem I see here is, the first mechanic told you that the spark plug was cross threaded, but what I don’t understand is, why did they work on the car with a cross threaded plug without removing the head? There Is no mention of how the mechanic repaired the cross threaded spark plug hole, although in your photo, it does appear that someone installed a new insert in that hole and then threaded in a new plug which ultimately broke.

That begs another question. If a new insert was installed, did the mechanic seat the insert too low and as a result, the piston hit the plug and caused it to break off in the cylinder, thus causing catastrophic damage? Unfortunately, I don’t see you getting out of this situation without paying something out of pocket for it.

IMO, the right thing to do here, may be for the first mechanic to meet you in the middle on the cost, since he said the plug was already cross threaded, which necessitated the need for that repair in the first place. With that being said, whomever cross threaded the plug has culpability there and if the first mechanic made a mistake by improperly installing a new insert that severely damaged the engine, then he too is culpable. That’s why I say meeting in the middle on the cost to repair it seems fair to me.

Yeah, sorry i should have put that in there. They did fix the cross threaded problem. Put an insert in. It was cross threaded before i bought it because when i replaced the plugs myself, it was super hard to take out but obviously the one i put back in probably followed the same threads. But yeah im not too sure what happened to make it break but they check it tomorrow and hopefully we can go from there. My problem is, i told them it was misfiring on cylinder 2.. why touch 3? Idk. It all blows my mind.

 

[ImBravo]

wow, never heard such a mishap. Wonder how they got a new plug in after the old one was cross threaded. you think a new plug won t be possible to just screw in. good luck.

They said they put an insert in to make it thread correctly again.. which im sure they did but did they do it right? Idk.. ive never run into a situation like this before

 

[cerbomark]

well just go forward and get it fixed right. I fear too many hands touched it now and no one want s to take responsibility is likely.

 

[Rapid Red]

That pic looks almost like the insert used was not the correct length. The plug threads are out beyond the insert?

I would be asking that question, I've used these on some dual plugged Harley heads. The plug thread were matched to the plug base. So just the electrode was exposed in the combustion chamber.

With all that crap on the plug beyond the end of the insert. There is no way that that plug was coming out without taking the insert with it.

That absolutely is a mechanic fuck up, get an answer about the correct sized insert that fits the plug, & should have been installed. Not talking about a "well, I was told" I mean written printable documentation about the insert, and it is out there.

Give a lawyer the documentation, have him write a letter as proof for what proper insert should have been installed, hand that to Mr Wizz the mechanic.

They thought what they did was going to get them paid. By the time you found that shit fix, they would be 1 bankrupt, or it held and you sold the car.

 

[NGOT8R]

Sorry to hear about your troubles. Please keep us posted on what the mechanic says and does about it.

 

[fmc_smt]

Just my opinion, the plug did not break . If you look at the plug the electrod is burnt off . This is an indication the the plug was not tight , or the insert was not to proper torque. First you have to look at what the OP stated , he changed the plugs prior . He also stated the plug came out hard . With that stated I would ask , if any coolant lose has been noted . Why you may ask , if you have coolant lose in these engines that will cause a spark plug to seize in the head . It takes a lot of talent to cross thread a spark plug , the tapper of the plug helps prevent that . I think this goes back further , to when the original plug was replaced . May ask OP did you bye new or used ? More information might be helpful.

 

[FreePenguin]

Ive been reading a lot of sad mustang post recently due to shady or bad mechanics. Got to imagine how many people get their toys worked on with hard earned money and broken everyday by people who dont know what they are doing or not being careful and not posting here on forums.

good luck OP. though how much damage can a little piece of plug really do? id imagine it would simply spit it out through the engine. an electrode isn't really very large, vs lets say the actual plug snapping out and bouncing around the engine like a marble.

 

[NGOT8R]

Ive been reading a lot of sad mustang post recently due to shady or bad mechanics. Got to imagine how many people get their toys worked on with hard earned money and broken everyday by people who dont know what they are doing or not being careful and not posting here on forums.

good luck OP. though how much damage can a little piece of plug really do? id imagine it would simply spit it out through the engine. an electrode isn't really very large, vs lets say the actual plug snapping out and bouncing around the engine like a marble.

I agree, it’s really pathetic. There are still some honest hard working shops/people out there, but it’s getting to where it’s very hard to take a chance on anyone. We have the shady people to thank for that.

 

[ImBravo]

Just my opinion, the plug did not break . If you look at the plug the electrod is burnt off . This is an indication the the plug was not tight , or the insert was not to proper torque. First you have to look at what the OP stated , he changed the plugs prior . He also stated the plug came out hard . With that stated I would ask , if any coolant lose has been noted . Why you may ask , if you have coolant lose in these engines that will cause a spark plug to seize in the head . It takes a lot of talent to cross thread a spark plug , the tapper of the plug helps prevent that . I think this goes back further , to when the original plug was replaced . May ask OP did you bye new or used ? More information might be helpful.

I bought it used 2 months ago. Haven’t had any problems until now. I didnt notice any coolant in there but i was losing coolant pretty bad since this happened.

 

[ImBravo]

Sorry to hear about your troubles. Please keep us posted on what the mechanic says and does about it.

Definitely will keep yall up to date. Sucks to have the happen. Only got the car 2 months ago. Im hoping me and the shop can work something out.

 

[Cobra Jet]

Did you buy the car from a Ford Dealer, private party or a "mom-n-pop" shop?

If Ford Dealer you might have some leverage to going back to them and see if they can offer any help.

Has the shop where the car is at bore scoped the cylinders to provide you with any pictures of the internal damages?

Did they remove any metal from the oil pan?

If it had a coolant leak while you had it, was the shop aware (did you let them know)? If they knew that bit if info I would have suspected the shop would have done a better diagnosis before just changing out plugs (again). I would not expect any private owner to "know" that when trying to get a plug out that if it was "tight" that concern would point to a cylinder head issue due to a bad head gasket or coolant leak.

If you are wondering about any prior ownership repairs and the car was purchased by you from a Ford Dealer, you can request an OASIS report to see what (if any) warranty or other repairs the vehicle had IF it was serviced at any Ford Dealer in the US 48. If it was not purchased at a Ford Dealer, there are also a few members on this site (there is a current open thread too) that can help with an OASIS report if needed.

 

[Rapid Red]

https://www.summitracing.com/parts/oes-25649


Thread Repair, Fix-A-Thread, 14mm-1.25, Spark Plug, Aluminum Heads,

That insert looks 1 1/4 inch to you?

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