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claymore 06-16-2009 11:07 PM

DIY GD3 removing replacing plugs and indexing
8 Attachment(s)

The following is provided as a GUIDE ONLY, and neither myself nor Honda Fit forums take any responsibility for the outcomes of someone else doing the following. You follow these steps at your own risk!


5000 Km rolled around and it's time to change the spark plugs in my Jazz Vtec GD. while this shows the GD a GE is basically the same procedure EXCEPT some people like to remove the "cowl plastic pieces" which is not shown here. I checked on a GE and I think with a cold engine you CAN do this on a GE WITHOUT REMOVING THE COWL PLASTIC.

If you are comfortable doing work by "feeling you way along" without looking directly at what you are working on you can do it on a GE.

We will also be talking about "Indexing" spark plugs. Indexing is not hard, or great secret but we will get to that.

Tools required:

Attachment 1024

The only thing that is a "Must Have" is a proper spark plug socket but more on that later. Another good to have but not absolutely necessary is some "Anti-seize" paste. It comes in a plastic bottle and is used on bolt threads to keep bolts from STICKING in treads.

For the Jazz a 6 inch ratchet extension is the perfect length but again a longer or shorter one will do use what you have on hand.

A 10mm wrench can be used in a pinch if you do not have a small 1/4 drive ratchet set but use a 1/4 inch ratchet and socket if you have one as it saves a lot of time leaning in over the engine.

An extra but not needed is a magnifying glass that I use to "Read" the plugs.


I use a one step colder plug and they are perfect for my driving style as we will see later.

Spark plugs today are built by computer driven robots and they come gapped to the proper specs. but as with anything it's best to at least give the gap a quick check. I prefer gappers that come with round wire type measuring indexes but there are many types out there. Avoid the "flat" type if at all possible.


When you are gapping your plugs BEWARE of the tool coming into contact with the ceramic insulator inside the plug. They are fragile and will crack if you hit them.

This is how you want your gapping tool to fit into the gap when checking clearance nice and straight

Attachment 1034

When some brand plugs come in the box the "top" is loose in the box and you have to screw it onto the top threaded part of the plugs in this photo NGK plugs came with it screwed on as shown where the pen is pointing.

Screw it on fairly tight, about as tight as normal pressure you can get using a pair of pliers, because you are never going to take it off and a good connection is needed.

Attachment 1027

Time involved:

This is an easy DIY and only should take about 1/2 hour for Vtec and maybe 1 hour on isdi engines.

Get Started:

I have removed and replaced literally thousands of spark plugs over the years and if at all possible do the job with a COLD ENGINE it makes it so much easier and is much better for your hands.

It doesn't take long to cool off if you leave it for an hour with the hood up like I did today the engine is cool enough to work on with no problems. :p

First steps:

First remove the plastic engine cover to get more room and prevent and damage to the engine cover on a GD you lucky GE owners will not have to remove your engine cover.... you don't have one like the GD.

To get added slack in the wires leading to the sparking units (coil overs) slide the black plastic clip out of the bronze metal bracket right behind the oil filler area.

Attachment 1028

It just slides out of the bracket.

Attachment 1029

To get at the plugs you first have to remove the sparking units (coil overs) they are located behind the engine just behind the valve cover. They are about square boxes about 1 1/2 inch wide with on 10mm bolt holding them down.

Modern engine no long have "spark plug wires" so don't bother looking for them.:rolleyes:

This is the bolt that must be removed ( what a job it was to get this photo)

Attachment 1030

Unscrew the bolts and BE CAREFUL YOU DON'T DROP THE PESKY LITTLE BUGGERS. After removing them over 8 times I dropped one today and after 15 minutes looking for it I finally found it wedged between the pipes on the top of the header. :(

Once the bolt is out the sparking units just pull off and it's easier to turn them left and right a few times to loosen them up.

Handle them a bit carefully as they are plastic and cause a lot of problems so no rough handling and no dropping.

Attachment 1031

When new they have a coating that looks like white baby powder on the part that goes down over the plug DO NOT WIPE THIS OFF as it's a dry lubricant and moisture prevention.

If you look closely on the right back section of the sparking unit you will see a light blue connector with a white bundle of wires. To remove the unit you MUST push in on the light blue connector clip to remove the connector from the unit DO NOT JUST TRY AND PULL IT OFF.

I personally like to remove all the units and let them dangle from their wires and then the plugs but you can remove the single unit and plug then move onto the rest one at a time if you want.

The wires are short enough it would be almost impossible to get them back on incorrectly but if your not sure just look at the plastic runner that is covering the wires as it has slots in it IN ORDER so you shouldn't have any problems getting them back on in the right place.

This is the only time I wished I didn't have a strut bar as it's right in the way of getting to the plug units but there is still room to squeeze your hand back there carefully.

Here is the reason you need a proper spark plug socket for removing your plugs. This is the soft rubber insert that comes inside the spark plug socket and "Holds on to" the spark plugs.

Attachment 1032

This is why you need a proper spark plug socket. When you are taking out your old plugs and putting in your new ones they are pointing straight up and down and if the socket is too loose the plugs could fall right out of the socket. So use an old plug and check your socket before you start to work. If it doesn't hold the plug snug enough that you can point it straight down get a new one or put some masking tape on the inside to make the plugs a snug fit.


I like to "Read" my plugs but it is part knowledge and part science and too long to teach you at this time. All it involves is looking CLOSELY at the gap end of your plug and you can determine the condition of your engine internal parts, it's fuel mixture, timing and plug heat range correctness. It's not too hard so if you are interested just Goggle "reading spark plugs" and read the results. But generally if the plug end is light brown you should be OK but if it is black and oily or the electrode looks melted it's time to check you engine for problems.

This is a perfect example of a good running plug. Note the small amount of tan looking crud that is what you should be shooting for. No black oily crud and no small black dots on the white insulator that would indicate detonation problems.

Attachment 1033


manxman 06-17-2009 04:15 PM

Thanks for re-posting your great DIY, claymore. Just a couple of comments. For the '09 Fit I-Vtec owners, add another 1/2 hour of labor for the removal of the upper and lower plastic cowl pieces, which is the only way to reach the spark plugs.

Another suggestion is to buy a magnetic spark plug socket. This will prevent the plug from accidentally falling out of the socket as you pull it out from the back of the engine, and more importantly, will prevent a new plug from falling out as you try to get it started into the cylinder head. Regular plug sockets have rubber rings inside the socket that normally hold onto the neck of the plug with friction.

One more little thing-- anti-seize compound around here comes in metal foil tubes, like toothpaste- not in bottles (at least that is the case with the chain parts stores). Tool supply stores that cater to professional mechanics probably have large plastic bottles or jars of anti-seize, maybe with a brush applicator fastened to the cap. A little anti-seize goes a long way. I have been using the same little foil tube for 10 years, and it's only 1/2 gone. All DIY-ers NEED anti-seize for any threaded piece that will be removed regularly in the future- such as wheel studs/lug nuts. On other forums, noobies are always complaining about how they broke off one or more wheel studs when they rotated, or changed out their wheels. Those people did not use anti-seize (or grossly over-tightened their lug nuts).

claymore 06-17-2009 10:10 PM

Sounds like good advice to me.

der Mond 06-18-2009 10:13 AM

Thank you both very much, this is a keeper.

macbuddy 06-25-2009 02:42 AM

Another low cost performance tip...

Originally Posted by claymore (Post 2202)
Notice that in the Jazz Vtec if the open part of the electrode is pointed straight toward the front of the engine it is pointed right at the intake valve.

Hey claymore,
Thanks for this DIY. I've done this to all my other cars in the past, just never got around to doing it on the Fit. I'll have this done by this weekend.


manxman 06-25-2009 06:48 PM

Hi Mike,
Welcome aboard these forums!

claymore 06-26-2009 01:36 AM

Hey Mike glad to see you are joining us here. The jazz/Fit is so easy to change the plugs if you don't have any strut bar it's could be a 15 minute job. I just did mine today and the news is not good..... the number two plug came out soot black. I had just cleaned the TB with spray cleaner so I'm hoping the soot is from the cleaner. If not maybe I have the spark unit failure a lot of people are having BUT it runs fine no misfires or rough running. So I will take it on the highway tomorrow and do a high speed run then pull number two and see how it looks with the new plugs.

More to come.

claymore 06-26-2009 11:51 PM

Whew dodged a bullet. I went on a run down the expressway and a couple of trips poking around town in traffic to load the new plugs. And the good news is the number two plug that was sooted up black on the old plug is now looking normal again.

It must have been crap from spray cleaning my TB with carb cleaner that sooted up the old plug. Funny how it with only the one plug but screw it it's back to normal now WHEW.

macbuddy 07-14-2009 03:37 PM

Reporting back...
Hey John,
I forgot to report back on the plug indexing. Wouldn't you know it, I removed and replaced the plugs, and found that all 4 were already facing in the right direction.
Normally, I would try different plugs and/or dfferent cylinders to achieve the desired direction of indexing. I read about using washers to accomplish this as well. What's your technique?

claymore 07-14-2009 09:15 PM

I just tighten normally and watch for the mark to get close then stop when it's lined up. Most of the time like you they end up in the right spot with normal torque only once did I have to leave it a little crooked because to get it straight would have meant over-tightening it.

I don't think washers would work because the built in washer needs to be squashed to make the seal and possibly it may make a leak.

But anyway while the extra few minutes it takes to index is worth it I wouldn't spend any large amounts of time trying to get one plug to index the gain is just (For me) not worth the extra effort for just one plug being a little off.

One other thing on that "other site" finally someone posted a bit of advice about colder plugs TWO YEARS AFTER I POSTED THE SAME THING ON THAT SITE glad they could catch up. Using one step colder plugs is a good idea and his results are great like 3-5 HP just for changing plugs. Worth the effort of looking around for colder plugs.

It's very simple chose which brand you want look on your old plugs and there will be a "6" in the number just ask for a set with a "7" in the number replacing the "6" bam a set of colder plugs. I have been running them in my car for about three years and never had a loading problem or any kind of problem.

I wish I had your scan gauge to check how much more timing gets put in with the change to colder plugs as I'm pretty sure that extra advance is more responsible for the increased HP than moving the tip of the plug further out of the combustion chamber which in effect would lower the compression rate by a minute amount.

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