[csmaan12]

Decided to change my spark plugs yesterday, because I was getting annoyed from the idle vibration, and I went out on a limb at guessing it was that since, its not an uncommon cause.

Anyways, I bought 4 NGK Laser Iridium spark plugs which are highly recommended for this car. I go to take out the old plugs, and they were some Denso Iridium...whatevers, gapped at .047, which apparently is out of the recommended spec for gaps, they didn't look old or burnt out or anything, so I even thought about putting them back in, but I said screw it, and changed them out to the NGKs. Lo and behold, idle vibration gone completely, and idling slightly higher (~750rpm), compared to the previous 600rpm.

I'm not 100% certain it was because of the difference in gaps, or just the quality of the plugs. Even though, I read around and it says proper spark plug gap is .039-.043, but its conflicting information, considering the OE recommended plugs are .044. Eh anyways, just felt that I should share this information.

 

[2.2Lude]

What was the gap of the NGK's you swapped in?

 

[EKJDM]

Aren't the NGK pre-gapped already. Plug and play?

 

[2.2Lude]

I work at O'reily Auto Parts, and can confirm they're NOT all preset. Reason why you should always check the gap before you install.

 

[csmaan12]

The NGK's are .044 pregapped. The old plugs were the previous owner's doing. Just wasn't something you think of doing when buying a car, checking the spark plug gaps.

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[gdub]

Yeah those NGKs are pregapped because I checked mine when I bought em and they all were. The part number is IZFR6K11

 

[curls]

The NGK Laser Iridium's IZFR6K11 are pre-gapped and I'm pretty sure I read on NGK's website (or on the packaging) that you are NOT supposed to adjust the gap on them at all due to the fragility of the electrode.

 

[DroBottles]

NGKs it is then all day!

 

[SumthngSynister]

yeah. everyone should check the plugs when they get their cars used. i got mine and tried to figure out why it was running like crap. took the plugs out and found out the last guy put Bosch copper plugs in. wtf?

 

[808havok_tsx]

Lo and behold, idle vibration gone completely, and idling slightly higher (~750rpm), compared to the previous 600rpm.

hrm... my previous car (now my sister's car) has a 600rpm idle... could never figure out why... it also has a slight idle vibration but i always thought that was because of the UR underdrive pulleys i had installed... the 600rpm idle and slight vibration remained even after the pulleys were removed.

when i have some time, i'll see if i can change out the spark plugs in her car and see if it fixes those issues.

 

[kewlliljethro]

Mine has a 600 RPM idle, but I have no vibration :O

I changed out the spark plugs bout 30k miles ago and have UR pulleys installed

 

[marshdh]

Large gap common after usage

It is perfectly natural for plugs to have a large gap after 40-50K usage. Modern ignition systems have the ability to fire a plug across wide gaps and performance degradation is minimal. However, I have an 05 TSX and when I changed plugs for the first time at about 50K miles I did notice an unexpected boost in performance and smoothness. As other people in this forum have stated "do not modify the gap on iridium plugs.

 

[tottenham12712]

I work at O'reily Auto Parts, and can confirm they're NOT all preset. Reason why you should always check the gap before you install.

No, you should never gap pre gaped plugs. They are pre gaped for a reason, they are coated, if you try to gap them you will run the plug.

The NGK Laser Iridium's IZFR6K11 are pre-gapped and I'm pretty sure I read on NGK's website (or on the packaging) that you are NOT supposed to adjust the gap on them at all due to the fragility of the electrode.

100% correct.

 

[evil804]

speaking of vibration, is it normal to have a vibration at idle when running the defroster or AC at full blast? nothing terrible, but its a noticable shudder at lights if i have the defroster or AC cranked.