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Discussion Starter #1
What is the gap for the 2.5, 4 cylinder engine, when using the NGK Iridium plugs? I can't find this info anywhere on the car and to further my frustration, there's no emission sticker under the hood...Final question, are there any tips for changing the plugs as it's a real tight fit reaching them. Thanks in advance...traintrackker
 

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Regardless of copper, iridium, platinum, it's the voltage that the coil puts out that more or less determines the gap.

.0039-.043 according to my manual (MY02 2.5)

Brian
 

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Update...Found out that the NGK plugs are supposed to be pre-gapped at the factory. Funny thing, the plugs I received from one auto parts place had different gaps set, per my gap tool. I ended up returning them and went to another parts place where I purchased some more. Hopefully, they'll be installed later today.
traintrackker
 

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Wait a minute....That's an old wive's tale about being pre-gapped. Never trust the factory specs to match your individual engine specs. Always check the gap. Remember, those plugs are made for many engines, and depending on what kind of spark control they have, the gaps will be different. Make sure you check. Brian
 

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Did check the gaps on the previous plugs and that's how all the mess started...The NGK's which were purchased at a local parts store had different gaps(3 were .42 and 1 was .45). I guess it was a bad day at the factory. Put the new plugs in after having to wrestle the plug wires off the plugs and glad I did. The previous plugs were Champions and they had seen some better miles. After a brief drive with the new plugs, things seem to be running better...traintrackker
 

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Gapping

.039-.043 I always gap @ 0.040 which will provide optimal burn over the longest amount of time (the gap get bigger as the spark plug is used because the electrodes wear away).

However, if you gap at .039 your spark might be to small.

Don't use the auto parts store suggestion of .044 to large!

I always get my plugs from the dealer because I know they are going to be in good shape. I have seen chain auto parts stores throw boxes of spark plugs around. It may cost more but at least you know they have been treated better before they reached your cars engine.

Never, never trust the gap even from the dealer always check and set yourself!!!!
 

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Buy a gap gauge (available at any auto store for $3-$5) Do not use the blade type only the wire type. Make sure it has a setting that is .040 on it. If you have never gapped a plug ask someone to show you (preferable a mechanic). It is easy to do but there are precautions. General rules:

1) No more than .002 adjustment at time

2) No more than .008 total adjustment (this is to keep the contacts as parallel as possible)

3) If the gap tends needs to be closed - this can be done by gently tapping the plug on a solid surface, checking the gap frequently. If you close it too far, do not lever it open against the central electrode, as the porcelain can crack - instead, use a plug gapping tool (this is on the gap tool you will buy) to pull the outer electrode open again.

Good Luck

*** Or you can buy Bosch Platinum +4 in which you do NOT GAP at all ever for no reason. I have never tried them but people do like them about $5 each.

Two types of Wire Gap Gauges (Picture links below)





[EDITED BY SUBHUMAN] to show images
 
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