mickey513

Went to two different auto part stores to buy the NGK 6994 spark plugs and ask the workers to double check the spark plugs to make sure it was 0.44 for me and surprisingly both time they were not. I understand that iridium spark plugs should be "pregapped" but these were way off at 0.35 to 0.38 ...

How do you you guys gap Iridium spark plugs to 0.44? What tools do your use since the center is so fragile and thin.

Eaglesfan9106

If you tried to measure them you ruined them.

ZOMGVTEK

I would question the test methods if you find such a large departure from spec.

Glance at them to ensure they didn't suffer shipping damage, and run them.

nfnsquared

^^^ fixed.

YeuEmMaiMai

those plugs are gapped from the factory. if you gapped them, they are more than likely toast as you took the point off of them...

mickey513

I did not gap them with the cheap 99 cent "coin", purchased a gaping tool from Sears that had hooks that allow you to gap without touching the iridium tip. I purchased the plugs direct from a local dealer after speaking to the Parts Managers about the gaps on the plugs. He confirmed that even though they are supposedly "pre-gap", the majority of the iridium plugs if you measure are rarely at .44, the shop that changed my plugs last time didn't even bother to check the gap before sticking them in my car, was driving around with sluggish acceleration and poor gas mileage.

And yes, you can gap iridium plugs if you have the right tools. I purchased a tool similar to one on this NGK plug video:


Hope this helps others in the future.

YeuEmMaiMai

not buying that explanation from your mechanic, sounds like he was talking out of his you know what. I have never had problems with any NGK plugs and I use them in EVERYTHING that I own

eastcoastguy

I have had the same problem as the OP, two different times from two different places the NGK 6994's were incorrectly gapped at .037. I know according to NGK's website that they can be gapped carefully and the right way, but why are they off by so much when they are supposed to come pregapped?

eastcoastguy

^^^^^ ignore this, sorry!

justnspace

iTrader: (1)

^butt butt, explain why, or what happened? just curious on why to ignore

eastcoastguy

Because I messed up, I was measuring the gap with a coin style tool and supposedly thats not how to measure Iridium plugs. I've been desperately trying to figure out : https://acurazine.com/forums/3g-tl-p...r-mpgs-959072/

Response I got from NGK

"Thank you for your E-mail. The Laser Iridium IZFR6K11 is produced on the assembly line at a 1.1mm gap ( this is where they get the 11 in the part number from). You cannot check gap with a coin style gapping tool due to the fine wire design, a wire or feeler gauge is required. These is a OE replacement design, meaning this is the same spark plug used when the vehicles engine was produced. They do not adjust gap at the factory. Recommended gap is a range, not a specific number. If you want to adjust gap you can, just use a tool that does not put any force on the fine wire center electrode."

Thanks for wondering!

justnspace

iTrader: (1)

cool! thanks for showing the email!
I never knew that it was a range and always thought it had to be exact. Thanks again

eastcoastguy

I think maybe that info should be made a sticky, because in all the threads I have seen nothing said in measuring the gap that a coin tool could not be used, or that the gap is a range. Also so many people still think its not ok to gap the plugs.

Octanee

I'm not sure where a coin gap tool even worked lol, the ramp is too steep imo, it'll throw you off by as much as 10 thou for sure. Always use a feeler gauge.

Gap wise, a longer gap to a degree can be desired, it leaves a longer spark arc. which can be good for a better burn. But the spark can get "blown" out if it's too long and requires more volts. higher compression or say turbo's you will want the gap to be less. Not sure what the exact physics are on that but with the boost it can literally cause the spark to not fire. Perhaps the denser air is more resistant to arc? Hmm.

So yeah it's generally a range. Try gapping your plugs to 30 thou. Can't go wrong there. May help In your case. As the arc would be considered stronger maybe, as I'm typing this I'm thinking I should of gapped. My new plugs lower, ah well, it runs...