MamaBear2015

We bought this 2002 Civic EX sedan with a Vtec engine about 6 weeks ago. We got very few receipts with it, but one said that the plugs were changed 2 years ago. So I went and checked one, and it was an iridium and the gap appeared pretty wide for a type of plug that I understand cant be changed from the factory gapping without risk of breakage.

I also looked up the car and Honda says to use platinum plugs in this engine.

So I just replaced them today, with four NGK Laser Platinum PZFR6F-11's, and comparing them, the new ones had gaps that appeared much smaller.

So I took my dial calipers and carefully measured the old ones and they had gaps around .065". I thought that iridiums couldn't be re-gapped, without risking breaking them, but am kind of puzzled as to how they got gapped that wide, and it doesn't appear that they were very old, or anything.

Anyway, the new ones had gaps around .045, which I believe is the spec.

The car started up much more quickly and easily with a rapid "varoom", then came down to operating RPM and seems to run much more smoothly with better pickup.

ezone

You probably could have regapped and reinstalled with no further issues.


The "-11" in the plug number is the gap in millimeters, the 11 represents 1.1mm. Honda gas cars have been using gaps of 1.1 or 1.3mm these days.

The gap on precious metal plugs can be adjusted by carefully bending the curved ground electrode, but you cannot use a cheap gap wheel as a wedge to jam the electrodes apart.

A commonly available and cheap tool:



IMO Platinum or Iridium, either work fine, there's no significant performance or lifespan difference as each have a 100,000 mile replacement interval.


Plain NGK V-Power plugs work fine too, but they wear significantly with use, 30k replacement interval is the norm for those plugs. (I put these in the 07 Fit I overhauled for the GF a couple months ago, because they are cheap.)

MamaBear2015

The ones I removed were ZFR6FIX-11.

ezone

Hmmm. Hadn't encountered a NGK number like that until now. Thanks.

The NGK site says the "IX" plugs are only designed to last 40-50k, so that means they wear and the gap probably increases as they wear.

PDF: www.ngksparkplugs.com/pdf/DYK/DYK_Laser%20Iridium%20vs%20%20Iridium%20IX.pdf

MamaBear2015

Don't see anything there, but I thought Iridium plugs were supposed to last 100k miles.... OK, I got the link to work. Didn't know that.

But the seller gave me a receipt saying these plugs were replaced about 11k miles ago by their mechanic.

I'm wondering if some silly person may have over-gapped them, and used a gauge to do it, damaging the electrode and causing erosion in the process?

Because in my photo above, that center electrode ( anode? ) looks eaten away some.

ezone

They must have precious metal on only one of the electrodes instead of both. Maybe to appeal to the value shoppers?

I'm used to seeing the longer life versions, I didn't realize NGK offered a cheapened version of a precious metal plug.
Anything is possible.

I didn't see any photo in your posts?

MamaBear2015

I'm seeing the photo above. I used drop box.

ezone

I see about 4 edit attempts but no pics, no link, nothing visible in the body of your post.

FYI Dropbox requires an account, the rest of us apparently cannot see your pics unless we are registered users......Maybe you can change your settings, make your pictures available to the general public?

MamaBear2015

I was only trying that because my FTP was down yesterday. Here it is:

ezone

^Doesn't look unusual in the pic IMO, but we don't have a brand new identical unit to compare with.

MamaBear2015

The gap is about .065 and the vertical electrode is eroded at an angle. 11k miles.