My neighbor is going to have to have one or maybe both cylinder heads pulled because someone neglected to put anti-seize compound on the plugs when installed in his 3/4 ton Ford pickup... He has an estimate of close to $700 to repair the plug holes... I won't install header bolts, spark plugs or EGT sensors without the stuff.

 

Not disagreeing but can you quote your references? The FAA or AF does not usually override a manufacturers recommendations. The AF publishes TOs that are written along side the manufacturer of the product. I have done this before.

 

Or improper torque? Over torquing is usually the culprit. Anti-sieze will reduce the friction and allow for over-torquing, which in some cases may strip the threads.

 

You can feel the increase in resistance when the crush washer is being squeezed as you are tightening a new spark plug and much more resistance when it is completely crushed.... Spark plug install w/o torque wrench..... - Honda-Tech

 

I'll try to remember to look it up when I'm at the airport tomorrow or the next day. As for the AF, I have been gone from there so long that I have no idea where to find it now.

An interesting story from about 15 years ago. We hired a recently discharged AF mechanic. I gave him a job one day cleaning and checking plugs on an annual on an IO-360. When he got done the engine ran terrible on both mags and would pass a mag check on either mag. I assigned another A&P to help resolve the issues. He was looking for bad plugs wires, a defective mag or two, or swapped plug wires. He finally pulled all of plugs and found anti-seize slopped all over the electrodes. No wonder the AF got rid of him.

The moral of the story is when applying anti-seize to spark plugs leave the end 2 threads bare and never get it anywhere near the electrodes. Also a little dab is all you need. He ended up washing then thoroughly in solvent and bead blasting them to clean it up. Aircraft plugs are close to $25 each and you have 2 per cylinder wired to separate mags for redundancy.

CHAMPION SPARK PLUGANTI-SEIZE from Aircraft Spruce

Spark plugs anti seize GOOD or BAD? - Yahoo! Answers

Anti-Seize Spark Plugs from Aircraft Spruce

Look at step 8 here:
How to install aircraft sparkplugs

Spark Plugs

 

Yes, it's interesting how a/c engines, military or civilian, have the magnetos and redundant plugs. I got my AP a disgustingly long time ago and the engines then look exactly the same as now. Little has changed, in the basic design at least.

I would only say that if the torque spec doesn't state to use anti-seize then don't use it. If it states to use it then use it. Because the anti-seize is basically oil, you're oiling the threads, reducing the friction... In my Fit manual it states a 13 ft-lb spec for anti-seized threads while the NGK instructions state 18 - 21 ft lbs dry. It's possible that on some plugs, maybe on a/c plugs the torque margin is so high that it makes no difference whether or not anti-seize is used. I think for the Honda Fit though, one is taking a risk using anti-seize and torquing to the full NGK dry spec.

 

I did not get time to look it up today. I was making upgrades and changes to the airport wide area wireless network and ran into some problems. I did not get out of there until 9PM. The airport manager added a firewall that he did not tell me about and screwed up one of my 4 routers. It took awhile to find a duplicate IP address he generated on the firewall. I love it when people install things and do not look at the over picture. It is kind of like someone who installs oversize tires and different wheels. Later they cry about their poor gas mileage or that the tires rub on the body. .
I'll try to get out to my hangar this weekend and look up the requested FAA reference.

After reading all of the postings in this thread I'm really wondering if it is worth the effort to chase it down. This thread is sounding like no one is going to change their mind anyway so why bother.

You are correct. Other than in the experimental category not much has changed over the years in engine and ignition design. Continental, Lycoming, a little Franklin, round engine Pratt and Whitney, experimental Rotax, and experimental VW is all that is out there with the last 2 being maintained primarily by owners. There is no reason for them to certify any new designs since there is very little competition and it is all regulated at high cost by the Government.

 

Good info!

 

I had to learn the hard way. Dont use the E3 plugs. They suck. There is a reason you pay $5 per plug. They only last for about 25k miles. Mine looked worse after 25k miles than my original factory NGK plugs with 100k miles. Stick with factory, its worth the extra price in the long run, not to mention my fuel efficiency dropped 2-3mpg with the E3s. I am very interested to see if my mpg jumps back up once I get the NGKs back in.

 

anyone tried spark plugs on a 2nd gen fit?

i think it is much more challenging.

the coil packs are almost unreachable.

 

It did. Dramatically. I installed new shocks, Progress springs, new coil packs, and new NGK spark plugs, and went from an average of 33mpg to 39mpg (averaged from three tanks).

 

I did use anti seize compound and torque it to spec. I didn't even changed the plugs I gapped it and cleaned it with fine sand paper. I saw a dramatic improvement on the fit.

I also used some dielectic grease. I placed a thin coating on spark plug only.

 

Hi thank for this post and for the comment, even with that war going on, My wife 2003 Corolla is at over 140 000 km ( like 90 000 for you US friends) so her Spark plug are due, and decided to do both my 2007 blue fit is at 86 000 km ( 54 000 miles) a little early but i notice a increase in fuel consumption lately and feel the engine is little less smooth. since i can do it myself and got both denso POWER iridium set of 4 for 58.24 $ CND ( the OEM long life were 74$). so why not this thread work for both car, fit need the IK20L and corolla the IK16 ( all taken from denso parts search) torque spec are the same. thank other who comment on the Di-electric Grease, the main post was not so clear about it, it should be corrected. i Bought a 5/8 spark plug socket ( both spark are the same size ) and a extension, i have a cheap torque wrench that work fine for the small work i use it for. not only i gonna save some money, but it might be fun :-) i'm no mechanic, but i like to do some dirty work for time to time! Thank again!

 

Thanks for the great post Sid! Been a number of years since I have done this sort of thing and didn't have the manual for my 2007 Fit. Dealer couldn't diagnose the mis-fire since it wasn't pulling a code. In hindsight I am glad since buying the plugs and coils online and doing it myself probably saved me a few hundred.

 

Thanks CTCT, for the link about not using anti-seize.

Thanks to the OP for the write up.

 

Thanks OP.

Because of your post, I just changed the spark plugs AND ignition coils in my '07 Sport.

 

At 114K and still on the original plugs, I decided to replace them. Ordered some Denso 3401's from rockauto and set to work to put them in today.

All was going well until plug #2...put the plug in, tightened, took the socket out....no rubber grommet in the socket. How this happened I have no clue, but the grommet got wedged between the threads and prevented attempts at extraction with various devices as well as not being able to get the socket back on to take the plug out. I flailed for a few hours and then called a mechanic I know to come over and help.

Final solution: Torch the end of the old socket until it's super hot, then jam it on the plug until it melts enough to get enough threads on to extract the plug. But then problem #2....bits of grommet still left inside. Had to go back to the homemade tools to get them out. Cleaned the plug of all melted rubber, waited for it to cool back down a little and then no problem reinserting.

And a last problem which my mechanic buddy couldn't solve either - the bolt on the last coil pack was frozen. Odd, since the car still had original plugs & coils until today, never been messed with since factory. No idea why that one isn't breaking but I could only replace three plugs this time.

Wow, this one did not go as planned. And I'm a bicycle mechanic so odd wrenching situations are nothing new.

 

Thanks for the DIY. I had everything I needed before I started which rarely happens. I wanted to change my plugs because I noticed a sudden decrease in mpg to 30mpg from 35mpg even after changing out the air filter. Hopefully it gets back up there by the next tank.

Only extra thing I would add is to tape the 5/8-in spark plug socket to the extension for old/cheap extensions. My socket wouldn't release the plug so I had to back out the spark plug all the way, then tape it. A few wraps of electrical tape was sufficient.

 

When tightening with a socket wrench, how do you know when you've applied the recommended torque?

 

you want to use torque wrench. when you reach a set torque setting, it will make click noise.