Based on a few scattered mentions on the internet about helicoil failing here and there... I'd guess it's the helicoil.

I did a re-thread on my spark plug about a year ago (Dec 2018), using a threaded insert. Its been something like 15k miles since and the spark plug hasn't backed out yet. I have 167k on the odo.

 

With mine ('11 Sport AT) at 40k-50k odo, the Check-Engine-Light (CEL) came on - misfire #2 & #3, the Vehicle Stability Assist (VSA) light came - disabled because of the CEL, and there was the odor of gasoline every morning on start up.

Wondering how other drivers are missing these signs and the FIT goes straight to: "Surprise" and the spark plug blows out. It has to take some amount of time days / weeks for a spark plug to unwhined, allow the combustion heat to harm the threads in the head and melt the coil pack to the point the plug 'ejects' from the head.

Are people purposely driving an ailing car (CEL on) until it explodes?

 

Mine smelled like gas for three months before I figured out it needed the plugs tightened. No CEL or power issues. It’s very possible to have a problem and not know. I imagine some ppl don’t get an odor, or just write it off as “well all cars smell a little”..

 

Last winter I had a cell for Misfire #2 and #3, just once. Went to my mechanic, checked all spark plugs, everything was OK. I didn't take the risk to not check them. Never came back since then...
That was on a 2014 Fit with around 70000km (Canadian 2014 Fit is the same as 2013 Fit).

 

It has to take some amount of time for the hot exhaust gases to erode the spark plug threads in the head. Only then can the spark plug come out and the head requiring thread repair. During that process, one must be getting 'clues' that something isn't right. I agree that some owner / operators just get in and drive without regard.

I live with such a person. Somewhere in Virginia while coming back to Pennsylvania from South Carolina the wife's CIVIC's low pressure TPMS light came on but she still drove the next 300 miles at +/- 60 mph. The next day, I was in the garage and notice that the one tire was flat and refilled it with air. I asked and she said, "Oh yea, a light came on but I don't know what it meant and the car didn't stop, so we kept driving." Lucky for her and me, I had put on those Bridgestone run-flat tires - apparently they really work above and beyond the call of duty (spec for 50 miles at 50 mph).

Later in the day, the tire was flat again, so I took it to the Firestone / Bridgestone store and they said that the tire was destroyed inside. Gave me $50 towards a new one. So, I get it all of the time that some have no awareness and even disregard the warning lights / signs no matter how obvious. I told her to call me or look in the manual if a light comes on. These lights / warnings actually mean something.

 

That miss at idle didn't cause the MIL (malfunction indicator light) to go on?

 

Yo I,m in my motor blew at 155k

 

Lets start about when to change/check spark plugs to avoid this motor blow up like mine
Billy Bullshit happening to anyone else
Especially Cylinder 3 like I am hearing constantly
not even 30k on plugs and the laser iridium was gone along with porcelain insulator on cyl 3 and 2

 

what would u like a picture of ?
Motor switched (WITH ONLY 21K)
IT was either valves or cylinder (155K)

replace coils
design of motor where spark plugs are is a FLAW - heat from exhaust
oh by the way u can change spark plugs /coils without removing the stupid cowl
reach around

 

There is an engine here with over a half a million miles and vast majority of fit vehicles and these engines run without issues.

If you are suggesting to change plugs and coils without removing the cowl, you are almost guaranteeing to torn the plugs incorrectly and cause an issue.

Fact is, by hearing about issues here in the forum tells us nothing about the incidence of this issue on a large scale.
We all know that people who come to forums is an extremely small percentage of owners and represents nothing is only a "racer wannabe who likes to modify the heck out of everything or race this subcompact as if (and some even go as far as installing) it has a turbo, boost... nitrogen oxide, performance ecu and other bullshit.

Do the maintenance, check your plugs at specified intervals (100K), don't abuse the car, and you are unlikely to have any issues. Do the opposite and you are guaranteed to have plenty of them.

 

Edit: Don't be rude

 

At about 60k miles, my 2013 Fit thru a code. Missfire #2 cyl.
car drove the same.
Cleared the code.
Day later, code came back and a little later, the car lost 1/2 power.
Turned car off and restarted and drove home ok.
I think the computer does this to protect converter. Maybe turns injector off.
Sort of screams, fix me!
Loose #2 plug.

 

just happened to me, 2009 sport, 62k miles. Through a code for cylinder 2 misfire. Plug was almost completely out. Changed all plugs and coilpacks and did a valve job, no more code. Cylinder #3 plug was also halfway out, too.

 

unfortunately, this seems to be happening to people left n right now

 

20 years of wrenching on my own cars, I don't use a torque wrench to tighten spark plugs. I always use anti-sieze which prevents galling threads, and I use a normal 1/2" ratchet that is about 12" long. This lets you feel the plug sealing washer crush. I estimate I get about 25-30 lb-ft.

Spark plug threads are large diameter with moderately fine thread pitch, so I feel you wouldn't start endangering the threads til you get over 50-60 lb-ft.

Learn to remove the plastic cowl behind the hood on the Fit, and this gives you a comfortable view and room to work in the area of the spark plugs

 

my fit just had this happen with 80k miles honda in jersey city quoted me 2900 for a head replacement and 4300 for a new swap And that is isnt i still owe 9k on the car and this happens anyone have any info on the size of the helicoil my grandson was able to remove the old spark plug but cant seem to thread a new one please help!!!!!!!!!! can u please email him directly @ tylerkotchkowski626@gmail.com

ALSO .has anyone tried to sue honda im not the person to run to the court system but this is really a tragedy

 

I would avoid the helicoil. I don't mean the brand, but the actual coiled wire type. I've seen a few mentions here and there (on the internet, not just this forum) about it coming loose.

I used https://smile.amazon.com/gp/product/...?ie=UTF8&psc=1 about a year ago (@130-140k on the odo) and the spark plug hasn't come loose, but then again, I haven't needed to check/change it yet. So in all honesty, I don't know if this could be just as bad as the helicoil. If you use this one, I would suggest using the longest one, it should be just enough to cover all the threads on the spark plug and keep that unexposed to the rest of the combustion in the chamber.

 

Freereign, if you could write a message that makes sense I would agree to read it. For example in your first message that I read you wrote: "Yo I,m in my motor blew at 155k." I have no idea what you are trying to say there. I read another message and it wasn't any clearer so I stopped reading your messages.

First of all I would ask: what is a "motor blew"? What is inside it? In other words, what is an "I,m"? How did an I,m get inside your motor blew and what did the I,m do when it got inside your motor blew? And when did it do that, after 155k feet, 155k meters, 155k miles, or was it after 155k days after it first got inside that it did something? Which is it? And did what? I,m has been inside your motor blew for 155k something-or-others and then – so what? Is it going to stay there? Is it going to leave? Is it good or bad for an I,m to be inside a motor blew? Why did you mention it?

I'm not asking you to produce great literature, just make a little bit of sense.

 

Yeah, that member hasn't been back in close to a month now.

 

Yo I,m still trying to figure out what he means when he said "Yo I,m in my motor blew at 155k"