Spark Plug Gap Tool--Iridium

[IndyFan]

What is the best tool for checking and adjusting the gap on irridium spark plugs? I've read that a standard gap tool can rub the irridium coating off of the electrodes.

Any help is appreciated!

 

[ElectroMechanoMan]

I’ve used feeler gauges, wire gauges, and tapered gauges for checking plugs and never had an issue. Just be careful not to force the gauge in the gap. If it goes in with more than a small amount of drag, the gap needs to be widened.

 

[kschachn]

It's not a coating, it is a solid piece of iridium alloy welded to the center electrode which is typically copper or nickel or both. The ground electrode can also have a small puck of solid platinum-group metal welded to the rest of the electrode.

Unless you have some desperately cheap plugs, and then I wouldn't believe it's actual iridium.

 

[xspeedy]

The idea is to not wedge anything into the gap to spread the ground electrode. So use a hook type.

 

[Lubener]

What is the best tool for checking and adjusting the gap on irridium spark plugs? I've read that a standard gap tool can rub the irridium coating off of the electrodes.

Any help is appreciated!

To minimize any chance of damage, I would use a flat feeler gauge.

 

[oldcodger]

I would think the wire gapping tool shown above would be best.

 

[Astro14]

It's not a coating, it is a solid piece of iridium alloy welded to the center electrode which is typically copper or nickel or both. The ground electrode can also have a small puck of solid platinum-group metal welded to the rest of the electrode.

Unless you have some desperately cheap plugs, and then I wouldn't believe it's actual iridium.

Which is why I check, gently, with a feeler gauge, and don’t adjust - too easy to damage those fine electrodes.

I have yet to find one out of spec.

And I have 24 Iridium plugs in each of the Mercedes, as well as Iridium plugs in the Volvos, so, I have checked a lot of plugs.

 

[kschachn]

Which is why I check, gently, with a feeler gauge, and don’t adjust - too easy to damage those fine electrodes.

I have yet to find one out of spec.

And I have 24 Iridium plugs in each of the Mercedes, as well as Iridium plugs in the Volvos, so, I have checked a lot of plugs.

I’m probably a black sheep in that area, I never check the gap and I don’t adjust it either. I just take them out of the box and install

 

[Hall]

Every manufacturer of Iridium plugs says NOT to adjust them. You can check them, but if they're out of spec, return them for replacements. If that means check 'em in the store, so be it.

 

[dishdude]

They're gapped at the factory and have the little cardboard sleeves to protect them, just do a visual check for damage and put them in.

 

[Chris142]

They're gapped at the factory and have the little cardboard sleeves to protect them, just do a visual check for damage and put them in.

That's what I do at work.

 

[ltslimjim]

The idea is to not wedge anything into the gap to spread the ground electrode. So use a hook type.

View attachment 317624

I used this type of tool to gap my twin-tipped Denso’s that I just installed the other day. Worked perfectly. No contact with either electrode. It’s likely, as others have said, you probably won’t notice a difference running them with the pre-gap they come shipped with. I just wanted to get it closer to the spec’d gap of the OE plugs; which is .052. The Denso came pre-gapped at .040 and with the tool I gently set them to approx .049.

 

[Thermo1223]

I’m probably a black sheep in that area, I never check the gap and I don’t adjust it either. I just take them out of the box and install

Same...

 

[SC Maintenance]

I check mine gently with a flat feeler gauge the next size down I have and eyeball it to make sure there is a bit of gap. I figure if there that close - then close enough. I also have never found one out of spec. If I did I agree, I would return it rather than attempting to adjust.

 

[MyWifesBoyfriend]

Always check the gap, especially if they are not the factory specified plug. You'd have to be ham fisted to damage the tip.

 

[TomYoung]

I’m probably a black sheep in that area, I never check the gap and I don’t adjust it either. I just take them out of the box and install

I check when I get the chance, but have not adjusted the gap since the eighties. I don't have proof, but I given the long, long lives of spark plugs today and the modern technology, I think that we have just moved to a different place. Kind of like how the thin oils have become so good these days, that you don't need the thick ones. Wait, did not mean to say that!

 

[D60]

I check - gently - with wire. Left pries open. Right closes. Neither touches electrode

 

[IndyFan]

Thank you all very much! I've got to swap out the original plugs in my wife's Compass. I also think I need to do them on my daughter's Renegade. Both are at around 110,000 miles, so slightly overdue, even though they both still run smoothly. Serpentine belts will be up after that.

 

[spasm3]

Which is why I check, gently, with a feeler gauge, and don’t adjust - too easy to damage those fine electrodes.

I have yet to find one out of spec.

And I have 24 Iridium plugs in each of the Mercedes, as well as Iridium plugs in the Volvos, so, I have checked a lot of plugs.

I check - gently - with wire. Left pries open. Right closes. Neither touches electrodeView attachment 317676

I think the issue with gapping iridium is if you use the coin type( with the ramp) that has you pry on the center electrode. Its hard but brittle and prying on it can break it.

I like the tools @D60 posted above. I use feeler and wire gauges carefully.

I usually undergap my plugs by about .005. @Trav and i have discussed in the past, undergapping plugs maybe easier on the coils. I have never replaced a coil or cop since doing this.

I gap them prying on the back of the non center electrode like this.

 

[georgef]

Serpentine belts will be up after that.

The serpentine belt isn't due until 150,000 miles.