Any engine with misfire detection is capable of misbehaving using NON-OEM plugs.
Iridium Plugs
- Thread starter DarthDuty
- Start date
A little lesson I learned the hard way..if you switch to a different type from OEM, follow the plug manufacturer recommendations for plug gap, not the vehicle manufacturer recommendation. I feel most issues come from the fact that, the vehicle system is optimized for a certain type and gap, and when that is changed the system is out of balance. My last truck,'10F150, had rough idle issues after a plug change from platinum to iridium, because I followed Ford's gap advice. Looked up the gap from the plug builder, which was different, changed the gap and it made a very noticeable difference. Just my $.02
Multi electrode plugs exist to meet emission related miles traveled before replacement requirements. Sharp edges and points allow electrons to to "jump" at lower voltages. (Hence points on "lightning rods"). My personal opinion is that many ground electrodes on a plug mask the air fuel mixture. The plugs on my cars and bikes are not hard to change so I stick with single electrode platinum NGK. If you have a vehicles which has hard to reach plugs, use the iridium. Just understand there's no magic to it.
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Originally Posted By: bbhero
Ahh that makes sense to me
Yeah if the car came with platinums I would use the same. Like with my ladies Camry.
OEM on Camry 4 cylinders back to at least 97 were dual ground iridium.
Ahh that makes sense to me
Yeah if the car came with platinums I would use the same. Like with my ladies Camry.
OEM on Camry 4 cylinders back to at least 97 were dual ground iridium.
My Tacoma (4.0 V6) came with platinum plugs, to the best of my recollection. 60k interval specified. I changed them early, put in Denso iridiums.
This truck spends more than half its miles towing a 5000 travel trailer (Manual transmission, a lot of time with the throttle wide open, 3k to 3.5k rpm). I pulled the plugs when they had 70k on them....There were still working just fine. I was surprised to find the gaps 3x the specification (About .120").
To my knowledge, there were no double iridium plugs available for this application. If there were, I would have bought them.
I put in another set, just like the last ones. I will check them sooner, this time. No really noticable difference in performance after the change. Never a miss, before or after, and instant starts, even in -10F weather.
This truck spends more than half its miles towing a 5000 travel trailer (Manual transmission, a lot of time with the throttle wide open, 3k to 3.5k rpm). I pulled the plugs when they had 70k on them....There were still working just fine. I was surprised to find the gaps 3x the specification (About .120").
To my knowledge, there were no double iridium plugs available for this application. If there were, I would have bought them.
I put in another set, just like the last ones. I will check them sooner, this time. No really noticable difference in performance after the change. Never a miss, before or after, and instant starts, even in -10F weather.
Hello,
1) Iridium plugs (ACDelco) came in the 3.8L Chevy V-6 I was working on. It had 96,000 miles.
As a "bargain" trouble shooting measure I replaced them with ACDelco's most basic plug of the exact same size.
The improvement was undeniable at idle and at speed.
2) My Volvo is non-turbo so I use the recommended 3 prong Volvo plugs. It makes life simpler.
Everything I've read (which is questionable because it's on forums) links iridiums with cylinder pressure.
It's as if you HAVE TO get iridiums if you have a high boost turbo. I do not know.
3) In the family's Saabs (all of which have a dedicated plug due to the fancy ignition system) the only iridium plug specced is for the '05 Aero-a higher pressure turbo.
The '99 and '02 are lower pressure turbo and use platinums.
Hope this illuminates. Kira
1) Iridium plugs (ACDelco) came in the 3.8L Chevy V-6 I was working on. It had 96,000 miles.
As a "bargain" trouble shooting measure I replaced them with ACDelco's most basic plug of the exact same size.
The improvement was undeniable at idle and at speed.
2) My Volvo is non-turbo so I use the recommended 3 prong Volvo plugs. It makes life simpler.
Everything I've read (which is questionable because it's on forums) links iridiums with cylinder pressure.
It's as if you HAVE TO get iridiums if you have a high boost turbo. I do not know.
3) In the family's Saabs (all of which have a dedicated plug due to the fancy ignition system) the only iridium plug specced is for the '05 Aero-a higher pressure turbo.
The '99 and '02 are lower pressure turbo and use platinums.
Hope this illuminates. Kira
Originally Posted By: Kuato
When switching to iridium plugs, be prepared to change back. I've seen far too many threads here, and other forums, where people had issues with iridium plugs.
I have put iridium plugs in a past vehicle that came from factory with standard plugs, it ran amazing I did check the gap though.
When switching to iridium plugs, be prepared to change back. I've seen far too many threads here, and other forums, where people had issues with iridium plugs.
I have put iridium plugs in a past vehicle that came from factory with standard plugs, it ran amazing I did check the gap though.
By my own experience the conclusion I got was that, IMO, iridiums can't deal with rich mixture and cold operation (read old engine/carb design) as good as old school plugs could. The porcelan tip has to be kept cleaner and they don't have that coating to avoid buildup and could short up or give misfires. Nonetheless in the right conditions, they are self cleansing at the root, when operated hot and lean.
But they are really good when new, because the impedance/resistance is lower and it fires even with a somewhat weaker coil or old wires. They need less energy to jump spark, when new and clean.
But they are really good when new, because the impedance/resistance is lower and it fires even with a somewhat weaker coil or old wires. They need less energy to jump spark, when new and clean.
Originally Posted By: Pontual
By my own experience the conclusion I got was that, IMO, iridiums can't deal with rich mixture and cold operation (read old engine/carb design) as good as old school plugs could. The porcelan tip has to be kept cleaner and they don't have that coating to avoid buildup and could short up or give misfires. Nonetheless in the right conditions, they are self cleansing at the root, when operated hot and lean.
But they are really good when new, because the impedance/resistance is lower and it fires even with a somewhat weaker coil or old wires. They need less energy to jump spark, when new and clean.
I use Denso Iridium plugs in my R1150RT BMW, which specifies copper plugs. Other than much longer life, the biggest difference is in much improved cold starting and cold operation after startup.
Changing the originals made a big difference (With another set of OEM plugs) at 12k. Changing the iridiums at 25k makes no difference in running, whatsoever. I suspect 50k is conservative.
By my own experience the conclusion I got was that, IMO, iridiums can't deal with rich mixture and cold operation (read old engine/carb design) as good as old school plugs could. The porcelan tip has to be kept cleaner and they don't have that coating to avoid buildup and could short up or give misfires. Nonetheless in the right conditions, they are self cleansing at the root, when operated hot and lean.
But they are really good when new, because the impedance/resistance is lower and it fires even with a somewhat weaker coil or old wires. They need less energy to jump spark, when new and clean.
I use Denso Iridium plugs in my R1150RT BMW, which specifies copper plugs. Other than much longer life, the biggest difference is in much improved cold starting and cold operation after startup.
Changing the originals made a big difference (With another set of OEM plugs) at 12k. Changing the iridiums at 25k makes no difference in running, whatsoever. I suspect 50k is conservative.
A couple of years ago I ordered NGK Iridium IX for my Zetec in my Contour. They were recommended replacement plugs for my car from Rock Auto. Just got around to putting them in this past fall. Turns out they are not really meant for waste spark ignition systems. Thought I was improving my ignition system, oh well, live and learn. The car is over 19 years old and doesn't get driven except in the warm weather, usually for vacations, 3,000-5,000 miles per year. So if I get 15,000-25,000 miles out of them I'm not complaining. They were half the costs of the Motorcraft plugs and the car runs really good with them. They have to be better than plugs with 60,000 miles on them. That's the change interval on my car with double platinum's.
Whimsey
Whimsey
Originally Posted By: Koz1
Originally Posted By: Kuato
When switching to iridium plugs, be prepared to change back. I've seen far too many threads here, and other forums, where people had issues with iridium plugs.
I have put iridium plugs in a past vehicle that came from factory with standard plugs, it ran amazing I did check the gap though.
Yep, some vehicle it doesn't matter one bit.
Originally Posted By: Kuato
When switching to iridium plugs, be prepared to change back. I've seen far too many threads here, and other forums, where people had issues with iridium plugs.
I have put iridium plugs in a past vehicle that came from factory with standard plugs, it ran amazing I did check the gap though.
Yep, some vehicle it doesn't matter one bit.
Why stick with OEM?
It puts the spark gap in the size and position where the engine designer intended and tested it.
There's also the matter of ground electrode number, position and flamefront shrouding.
How close do the other brands get it?
Often not close enough.
It puts the spark gap in the size and position where the engine designer intended and tested it.
There's also the matter of ground electrode number, position and flamefront shrouding.
How close do the other brands get it?
Often not close enough.
Waste park ignition will need plug with dual metal tip, either iridium, platinum but not just normal plain ground electrode. There is a few NGK IX model that comes platinum chip on the ground electrode. However, nowadays, it is very easy just get the denso iridium tt or ngk ruthenium model, all of these comes with dual tip and outlast your original plug if it didnt come with iridium. Just make sure when you install new plug, your gap can not exceed the original more than 0.1mm. otherwise you may have idling issue when your ignition power is weak. This gap many times are overlooked and people blame iridium plug is the problem.
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