spark plugs

[justinf89]

About a year ago, after I got my explorer, I checked the spark plugs and re-gapped them. I was suprised to find iridium plugs, although improperly gapped at .04in when they are supposed to be .054in. They looked in pretty good shape so I put them back in.

Last black friday, I got a free set of platinum plugs for it for when the time came to change them. I plan to take one out today or tomorrow to take another look at them.

I'm not too familiar with iridium plugs so how do I know if they are worn out? I don't want to change out perfectly good iridium plugs for lesser platinum ones. Thanks guys.

 

[ltslimjim]

I've heard that iridium don't necessarily always last longer, depends on the quality of the brand of iridium plugs in your vehicle and if your app has seen severe service or non-optimal conditions I've heard tale of perhaps the iridium actually failing at the tip somehow?

 

[justinf89]

I'll take one out or maybe one side and take pics of them and post it.

 

[NHHEMI]

Originally Posted By: justinf89
About a year ago, after I got my explorer, I checked the spark plugs and re-gapped them. I was suprised to find iridium plugs, although improperly gapped at .04in when they are supposed to be .054in. They looked in pretty good shape so I put them back in.

Last black friday, I got a free set of platinum plugs for it for when the time came to change them. I plan to take one out today or tomorrow to take another look at them.

I'm not too familiar with iridium plugs so how do I know if they are worn out? I don't want to change out perfectly good iridium plugs for lesser platinum ones. Thanks guys.


If you regapped them to the proper gap you more than likely ruined them. Iridium plugs are not supposed to be gapped. It damages the Iridium tip. I would say plan on changing them out for the new platinums.

 

[tinmanSC]

Iridium plugs are "long life" plugs in most cases. However some manufacturers are making them into performance plugs, and are not intended for long service life (NGK has some of these, I think Denso does too so check the type was that put into your car.) Amazingly, some of these Iridium plugs are lasting the life of the car, but technically they are to be changed at 100K-150K intervals.

Gapping an iridium plug is also a no-no. Due to the properties of the metal it can have a larger or sometimes shorter gap. For larger, this gives you more spark to start your flame-front in the combustion chamber. This is good. I'm not sure why they say shorter sometimes.

 

[EricF]

iridium tip plugs are the plugs designed to go 100k. they are not to be gapped or adjusted.
Usually they have a platnum tip, so they were OK to use in your explorer (the V6 motor needs double platinum plugs due to the waste spark system).

I've never seen a worn out iridium plug yet.. I would say the fine tip won't be fine anymore?

 

[justinf89]

Thanks guys. I gapped them well over a year ago very carefully not to touch the tip. I didn't know that the gap may be different for them though. The iridiums listed on ngk have the same gap as the coppers so I just assumed they needed to be .054. The plugs are motorcraft so they might be original for all I know. The explorer ran fine afterward, and has ran fine for the past 20k miles since I gapped them. I've gone on 4 trips from va beach to chicago on it too and it does fine. I think if I damaged it I would know but I'll take one out to check.

Edit: How would I find out what the gap should be for motorcraft iridium if they are original equipment and the manual says .054? When I checked them they were all down to .04 or more.

 

[justinf89]

My bad guys, the plugs are platinum. I saw the thin tip and assumed it was iridium. My question now is, why does the platinum champion I got as a replacement look so much bigger? The tip on the motorcraft does look a little rounded but it's not worn down that much.

 

[GMBoy]

Originally Posted By: justinf89
My bad guys, the plugs are platinum. I saw the thin tip and assumed it was iridium. My question now is, why does the platinum champion I got as a replacement look so much bigger? The tip on the motorcraft does look a little rounded but it's not worn down that much.

The motorcraft plug has a platinum center electrode where as the Champion takes the cheap way out with just a platinum "puck" attached to the ground electrode...looks like a little dot welded on there. The OEM plug is a "better" pluh, but I would still go an use those Champions. You'll still get 40-50k miles of life from them.

 

[ltslimjim]

I have to replace my OEM plugs every 30,000 miles.

 

[justinf89]

Ok so I checked and it does have the waste spark system. Does that mean that the motorcraft platinum's were inadequate? They aren't double platinum but in the motorcraft parts store online, those plugs are the one's spec'd. Now I'm confused.

The center tip listed for the motorcraft sp500 in there now is iridium alloy, and the ground electrode is nickel alloy, yet the plug is called platinum?

 

[mgm13]

Use the MotorCraft plugs as almost anything is better than Champion. If you want better buy NGK or Denso. The smaller the size of the tip the less energy it takes to fire it. Many of us gap irridiums without any problem, just be extremely carefull.Also less gap normally means stronger spark not as likely to be quenched or blown out.

 

[Steve S]

I would replace the plugs with the exact plug the manufacture uses.

 

[mechtech2]

Waste spark ignitions require that the plugs fire both ways, depending on the cyl they are in.
So Double precious metal tips are required [factories often use special single plat tipped plugs with the plat on either end, but they are cylinder specific and not available to the public]

You can and should gap all spark plugs. that is why there is a spec for them!
But anybody can screw up anything. Use care.

 

[GMBoy]

Originally Posted By: mechtech2

You can and should gap all spark plugs. that is why there is a spec for them!



AMEN!! If I had a nickel for every time I heard a parts guy tell a customer that the plugs are pre-gapped at the factory, I'd be rich!

Problem is the pre-gap is averaged to meet several applications - not just the car you're buying for. So, yes! Gap all plugs before install..except special plugs like Bosch +2, +4's and some iridiums with a tiny electrode that will break easy.

 

[dwendt44]

NGK Iridium plugs are pre-gaped. And, from my experience quit accurately.

The 'suffix' is the gap in millimeters. (ie. -11=1.1 mm)

I recently purchased a NGK plug for my B&S Intek engine in the lawn tractor. Engine calls for .030". NGK doesn't make an Iridium plug in that gap, so I got the same heat range in a wider gap (.043) and closed it up to .030". No problems so far.

 

[justinf89]

Thanks for all the help guys. I think i'm going to go back with the motorcraft's since there not that expensive, and I don't have to worry.