Thanks GAFIT! I used 16ft/lbs for my latest install since I could not find the torque specs for the spark plugs mentioned in the Haynes or owners manual.

We must have 14mm thread spark plugs then. I see elsewhere the recommendation is "approximately 7 to 15 lb. ft. for 14mm threads, and 15 to 20 lb. ft. for 18mm threads " according to Pep Boys.

https://www.pepboys.com/car_care_cor...l_and_removal/

 

Been reading on this forum and other places for several months that I'm not the only one having this spark plug issue with a Fit. Here's my story: We bought this 2008 Sport when it was 2 years old and had about 10,000 miles on it. Late last winter we decided we would go on a road trip in late April that ended up being over 5,000 miles. In planning for it I figured I'd replace the timing belt since the car had about 80,000 miles on it. What a joy when I was looking for a belt kit online to find out it had a chain! That made me so happy that I had the Fit, since that meant someone engineered a quality car into it. So, I decided to give it a new set of plugs and other regular maintenance stuff. On the trip most of the time it got really good gas economy except for a couple of tankfuls where it got below 30mpg and had a slight miss. I figured it to be bad gas since everything improved with the next tankful. After we got home 5 weeks later it seemed to run just fine until about 2 weeks later when it developed a real miss. Well I've been working on my own vehicles for over 50 years and the first thing I do to chase down a miss is pull a plug. I don't remember which one I pulled but it was likely #1 since it is the easiest to get to. BTW I have never had to pull off any cowl parts to get at the plugs. To my surprise it was finger tight. So, on to #2. same thing. #3 was really loose. 4 was somewhat loose too. So I snugged them up just like I have done on plugs before (yes even on aluminum heads) and although mystified I figured it was fixed.
Next trip into town (about an hour away) my CEL comes on. Checked it and it had a #3 misfire code. I finished my business and limped home. Ever since then, whenever I travel more than a 50 mile round trip, at least one plug is loose. Because of info on this forum i started to use a torque wrench, but became wary of going over 15 pounds. I've tried putting blue lock tight on the threads first, then tried putting it on the crush washer. Eventually tried a whole lot of it, like mabey 20 drops. Ya know the stuff is only good for 450 degrees so I'm not surprised that it didn't do much good. All in all I've been dealing with this 2 or 3 times a week. Last time I torqued them to 20. I have several pro mechanic friends and they all said they have experienced loose plugs on different kinds of vehicles, but usually just tightening them without a torque wrench fixes the problem and none come loose again. One suggested using one of those flat lock washers. Haven't tried that yet. Wondered it it would keep things from sealing right.
Since there is an Army of us having this same basic problem, it's obvious that this is an engineering flaw and Honda needs to step up to the plate. I'm not a sue happy person but someone posted on the forum the idea of a class action lawsuit. I applied for one at: https://topclassactions.com/ a few weeks ago but haven't heard back. Maybe you all should do so and help get some attention.
I hesitate to do a heli coil because of loose metal getting in the combustion chamber. I'm trying to read more and think things through before I do something I'll regret later. I still like the car and the idea it has a timing chain. I've maintained it well and want to keep it for about a million miles. It still has it's original tires and they look good.
Just my 2 cents for now. I'll write more when I think of it.

 

BTW: I happened to be driving past the Honda dealer a couple months ago so decided to drop in. I asked the shop manager if they ever found a fix for the loose spark plug issue. He said he doesn't know of any issue and said I obviously over tightened the plugs. He said they should only be at 14 pounds. So, they are in denial. I spoke with the parts guy and he told me that their supplier(I guess Honda America) charges them more for the NGK plugs than he buys them for himself at O'reilly's. That's all he said.

 

I have two Fits with high kms, 239,000 and 309,000. I have posted before and still highly recommend to rechecking torque on plugs at least by first 50,000 and I replace mine at 100,000 instead recommended 168,000.
I have owned Honda’s since 1980 and years past this has never been an issue with copper core plugs but they were replaced every 24,000 and then 48,000 as per Honda. Copper core center electrodes wear much faster than platinum and iridium, thus the frequent replacement, but they are 1/4 the cost.
Note HONDA is not the only manufacturer having this problem. I spoke to a fellow who worked at Ford and they have same issue, with most just blowing out of the cylinder head and costing big bucks.

2015 spark plug
I think the manufacturer is trying to resolve these precious metal plugs from coming loose starting on the 2015 Fits. Check out the price!! and they have been redesigned as the plug combines both precious metals by adding one to the ground electrode. Also the reach is substantially longer than past plugs...I think to create about 25% more surface contact area to cylinder head. Another note it requires a 14mm deep socket.

This is a educated guess on my part. I know this because I was changing plugs on my daughters Fit

 

I have to check them every 50 miles. This until I find a permanent fix.

I heard the ford problem is only certain engines and is fixed just by retorquing them once.

 

its not an official fix...but my recommendation has been to treat the plugs like they are one time use. i believe once u crush the washer even at 14 lbs, and or back the plugs out, its done and will never hold again even at higher torques. id say have a set of plugs on standby, and next time you check them and if they are loose just replace all of them and take them to 20 ft lbs. and after that if you "check" them, only turn in the tighten direction with the torque wrench.

i had a couple of loose plugs on my car a year and a half ago. the loosest one was tighter than hand tight, but definitely not at the recommended torque. replaced all of them and have done what i described above and they have been fine.

anyways, keep an eye on em and i hope u get em sorted

 

Perhaps, but why are Fits unique in this problem. I have had Accords, an Integra, and Subarus. None have this issue. Put plugs in my 99 Accord and there fine. No issue.
On my Fit I've been checking them in the tighten direction for a while and snug them to 20. Just buying time until I find a real fix.

Thanks for your input eulogy.

 

idk ...not sure anyone's figured it out. chalk it up to a design flaw i suppose. there has been theories its related to exhaust port design/location.

 

I read somewhere the idea that there are more threads on the spark plugs than the head has. In other words the length of the plug barrel is more than the length of the threaded hole of the head. If so the tip of the plug would extend into the combustion chamber by a few threads. When I get some time I'm gonna send my camera in there and try to count the threads to see if this is true. If so the theory is that carbon builds up on the few spark plug threads exposed in the combustion chamber and the first time the plug is pulled those deposits damage the threads on the head. After that the any new plugs would not be held as securely as the original.

If true the design was like a time bomb set to go off after the warranty is over; whether intentional or not.

 

We have an '09 Civic and the '11 FIT Sport AT (original owners of both). Like you, no plugs problems with the Civic (~135k miles) but on FIT I started to notice the odor of gasoline on start up but chalked it up to rich mixture (winter) but then the CEL and VSA lights started to come on ~38k miles. Initially, the code showed misfire in #2 cylinder and I made the mistake of taking it to the dealer: $50 diagnosis, claimed it was a bad coil pack $160, that required $50 of labor to install. Within 2 days, the CEL & VSA lights were on but this time the codes indicated that #2 & #3 were involved. The dealer said, "Oh you need another coil pack." Lucky for me (not sure about that), I had asked for the old coil pack, which they gave back in a bag / box, so I hadn't looked at it until then. Sooty, and I could smell gasoline, and I'm thinking, "How can piece of equipment completely outside of the fuel feeding / combustion / exhaust smell like gasoline?" I did the old left-handed reach-around and that's when I noticed that #2 & #3 plugs were only finger-tight. That's when I started thinking that those SOBs at the dealer have a gold mine going here, by changing $160 coil packs +$100 of diagnosis & labor and they can do that four (4) or more times on each FIT, but never fix the 'real' problem. When I eventually addressed this myself, I put the original coil pack back on #2 and it remains there today performing without flaw / error codes. Regardless of the coil pack cost (OEM / aftermarket), I'm amazed that so many owners opt to replace these when the underlying problem, 99% of the time is only the loose spark plug. See it all the time on this forum.

I installed new NGKs so that the crush washer was new, I removed the HVAC cowling (lost one of those $3 plastic pins around the windshield molding), and held it to the OEM torque spec. That worked for another 8k miles, then #2 & #3 loosened up again, but this time, I just reached in and hand-tightened. That was good for another 5k miles, then it happened again. At 51k miles on the odometer, I hand-tightened each plug (relatively new NGKs with the already 'crushed' crush washers) after applying blue Permatex threadlocker paste (not a lot though). I now have a hair over 80k miles on the car and it has been good ever since - nearly 30k miles.

I now do a lot of local driving, so many hot-cold-hot cycles. Maybe I caught mine in time before there was any significant erosion of the threads (head) by the bypass of hot gasses but that little bit of blue threadlocker has held things together for me.

In late 2017, I took a welding class at the local Vo-Tech and one guy there would come from work in his tech uniform from the same Honda dealer that I use for parts & the now infamous coil-pack replacement. I causally asked him about where he worked, etc and then asked about FITs and loose plugs and he said that it was a 'known problem'. Again, that confirmed to me that the dealer couldn't be trusted.

During the airbag recalls (both sides on the FIT but only driver side on the Civic), I'd ask different service clerks (they write up your work order after diagnosing the problem, etc, before it goes back into the shop), when should I think about changing the power steering fluid in my FIT. Not one of them knew that it was electric, had no fluids to change, but all three (3) of them said that I should do it around 60k miles. When you go there, you've got to know more than they do and challenge them or you're getting screwed.

Same thing happened when every damn TPMS sensor battery died, one by one, all four (4) wheels, after installing new tires. I bought OEM ones at the parts counter for $48 / ea and had an outside garage program them to the car but then they declined if I wasn't buying the sensor from them. So, on the last sensor that died, I when back to the dealer and checked at the parts counter before heading checking in and getting my work order written up. OEM TPMS sensors were still $48 ea. When the service clerk started doing the work order for my car, he says that the sensor was $75. Told him right there that I'll walk over to parts and buy it for $48 and hand to him, not going to pay $75. He backed off. You just can't trust them and I shake my head thinking about that fact when I look at the 30-50 people sitting in the waiting room there eating popcorn, drinking coffee, watching TV - all 'numb' to what's going on - like sheep to the slaughter. Overcharges / needless repairs / due to poor product knowledge / outright lying. I'm sure somewhere and sometimes there are honest dealers / service clerks / shop techs, so not trying to paint them all in negative light but you have to 'know' what's going on more than they do. For me, I'm only going there when I don't have the special tool / electronic thing to do the job that I already know how it's done.

 

FWIW: At least your not alone.

 

I don't even bother with TPMS sensors. I just check air pressure like we always did. I ignore the warning light.

 

I'm in Pennsylvania and we have an annual vehicle safety inspection: tires, brakes, exhaust, lights, wipers, windshield, and how it feels when driven by the tech. Hooking up the OBDII port to a computer and reporting out the results of system error codes is done too (I get a readout and so does the State Dept of Trans along with mileage, proof of insurance coverage & proper registration ownership).

So, any reputable inspection station 'won't pass' any vehicle with warning lights constantly on 'or' stored in the computer even if not showing on the dash display. They can also tell that the memory was recently erased (erasing codes) and the vehicle hasn't been driven 50-60 miles to refill the memory, thereby, not 'truly' representing the condition of the vehicle's safety system codes. They can fail you but you still have to pay the fee and come back again for more $.

So, I can't be a tough-guy and put electrician's tape over the displays I don't like. I have to fix things so they are working properly. Sooner or later, running without the appropriate inspection stickers (color coded so the police can instantly know if you're out of compliance) costs $100 - $200 and you have to get it fixed within so many days and then prove it to the police that issued the ticket. We also have plenty of local & state police, so only a matter of time before you get pulled over.

I do appreciate knowing that others sharing the road are held to the same high standards on their vehicles (does,'t stop someone turning left in front of you or hitting a deer) but I have friends in Ohio and their vehicles aren't inspected and they routinely experience breakdowns & significant safety failure. Maybe I need better friends?

I hope you can appreciate that, for me, where I live, and from past experiences, it's better just to fix things, on you're own terms, when they need fixed.

 

Yeah, I grew up near Allentown and back then they did inspection twice a year. Frankly it was a racket. It's one of the reasons I live in the Rocky mountains for the last 39 years. They don't have inspection here. People seem to just take care of their cars without being treated like children. Last spring we drove to PA with the Fit without any trouble at all. That was right after I changed the plugs for the first time at about 72K. The problem didn't start until we got back, having put about 5K on the car.

It's interesting that your plugs seem to behave better than mine. Wonder why?

 

Is "blue Permatex threadlocker paste" a paste not liquid? How do you apply it?

 

It's in a tube with a twist bottom / screw. Pushes up and out a nozzle. Tastes sweet.

Yes, I too remember the twice a yr PA inspection. Any rust, anywhere, was a reason to fail. I think it's different now and they are only concerned with a rust hole into the cabin, whereas, a fender is OK. A lot of Bondo work on junk back then.

 

I remember road crews in PA throwing salt on roads before they plowed off the snow. What we they thinking? It's supposed to melt ice not the snow. That stuff really eats up a car. Out here they don't put salt down. They use something different and only when it's extreme. We also have less traffic.

I've been torquing to 20 lately. Seems to be holding. When I recheck them I turn them in the tighten direction with the torque wrench. None seemed loose but checking in the tighten direction doesn't seem conclusive. It's hard to tell if they turn, if for example one is down to 19. But, none were "very loose" for sure. When using a torque wrench in the loosen direction you can definitely tell how tight they were.

I got some green lock tite that I may try at some point. Or perhaps the permatex blue paste.

 

I have three (3) motorcycles and anything that comes off goes back on with that blue paste. I never liked the liquid version even though it tastes the same. I've settled on the paste version.

 

That's interesting, I'll have to try it. I used to travel on a Harley Panhead and nothin vibrates like they do. I used locktite blue for everything on it and it always worked. But, the spark plugs never came loose! Didn't have to locktite them. Think about that HONDA!

 

Some noted, in other threads, that they think that the aluminum head heats and cools in peculiar ways that 'work' the plugs loose in #2 & #3 (those seems most often mentioned).

Motorcycles vibrate everything loose. I hate paying $4 and waiting 1.5 wks to get a lost screw / bolt. The '15 V-Strom I have is like undressing an Amish girl with all of these peculiar nuts / bolts / pins everywhere. Sometimes, the finish stuff on the left side is different than the right holding the plastic together. I take a lot of pics / label baggies. Scary.