Iridium Spark plugs are they worth it.

[Hobo,NC]

2007 Suburban 5.3 with 618K on the clock, on its 3rd engine.







History the top two plugs are NGK platinum have 325K on them and the bottom two AC iridium352K, 25K after I put the plugs in it had a misfire I replaced two plugs with NGK and never changed them back to the AC. The misfire was not the spark plugs a fuel injector was going bad. The NGK have over .100 gap the iridium have .010 over the original .040 gap. The insulator had broken off one of the AC plugs.

He has been saying for the last few years he was going to replace this vehicle so it’s been on life support to just get by. In the last year he’s had to rebuild the transmission the original went 500K. The transfer case just went out along with the differential. Its always ran out well but its starting to show its age. All the pattern issues with the 5.3 are back.



The original engine went 260K he replaced it with a used engine that lasted 150K. I put a GM reman in it that has about 220K on that engine now. He made a bad call on going with a used engine it cost him thousands of dollars to put a used engine in it that already has 150K on it.



I learned my lesson on aftermarket water pumps on this one they ate my lunch. OEM is the only way to go: ). I’ve only charged the AC one time the AC clutch is worn slap out now I took the shim out of the clutch hub we will see how it goes.

It’s been replaced he’s keeping it as a backup. I would have liked to have a fleet of these to work on as its kept me up well. Every 5K its showed up you could set your clock by it. If you want to know I worked on it open the hood.

 

[DPittman]

Don’t know about the plugs but I know you must really love that Suburban. We got a 03 with 262k on it and it just about done. Still starts and drives and the air is cold but the Illinois road cancer has killed it. Can’t p any more money in it but I hate to see it go. One of the best vehicles I’ve ever owned

 

[DoubleO7]

He put the old used plugs into the replacement engine?

 

[M-MAN]

Probably be better off going with the cheapest plugs you can find. At least then he would have to change them in a sensible time frame.

 

[Hobo,NC]

He put the old used plugs into the replacement engine?

Yes and got another 200K plus out of them. I will say this strange unusual misfire he had has gone on for awhile. It would have a random misfire cold and go away once it got up to operating temps. It would not show up on the misfire counter. At this mileage it could be anything as 7 of the injectors are original along with the ignition coils.

Its a spare now so I he left it for me to drive I thought it was time for some plugs : ) the misfire is gone.

 

[Hobo,NC]

Probably be better off going with the cheapest plugs you can find. At least then he would have to change them in a sensible time frame.

Iridium is top dog in any fight 350K with little ware verses the other plug is all the prof I need.

 

[J Hamilton]

Iridium is top dog in any fight 350K with little ware verses the other plug is all the prof I need.

NGK iridium is all I put in my vehicles. Never had an issue with them.

 

[Geo-TH,In]

2007 Suburban 5.3 with 618K on the clock, on its 3rd engine.







History the top two plugs are NGK platinum have 325K on them and the bottom two AC iridium352K, 25K after I put the plugs in it had a misfire I replaced two plugs with NGK and never changed them back to the AC. The misfire was not the spark plugs a fuel injector was going bad. The NGK have over .100 gap the iridium have .010 over the original .040 gap. The insulator had broken off one of the AC plugs.

He has been saying for the last few years he was going to replace this vehicle so it’s been on life support to just get by. In the last year he’s had to rebuild the transmission the original went 500K. The transfer case just went out along with the differential. Its always ran out well but its starting to show its age. All the pattern issues with the 5.3 are back.



The original engine went 260K he replaced it with a used engine that lasted 150K. I put a GM reman in it that has about 220K on that engine now. He made a bad call on going with a used engine it cost him thousands of dollars to put a used engine in it that already has 150K on it.



I learned my lesson on aftermarket water pumps on this one they ate my lunch. OEM is the only way to go: ). I’ve only charged the AC one time the AC clutch is worn slap out now I took the shim out of the clutch hub we will see how it goes.

It’s been replaced he’s keeping it as a backup. I would have liked to have a fleet of these to work on as its kept me up well. Every 5K its showed up you could set your clock by it. If you want to know I worked on it open the hood.

I bought OEM plugs for my 2007 GMC work truck off Amazon, very reasonable price.
Are they worth it. Yes because I will only use what the smart people that built my truc used.

 

[4play]

Regular old "copper" nickel plugs give the best spark, platinum triples the life span but with higher resistance, it has a weaker spark. Iridium plugs have better life,with a better spark vs platinum. Nothing requires iridium, or even platinum, it's a selling point to extend maintenance frequency. Iridium has almost replaced platinum in all OEM's now. Platinum plugs are basically obsolete, probably going to hang around as long as people are buying them.

Are iridium plugs worth it? I think so, at least on stuff you want to keep and last. Let your wallet decide, but platinum or iridium will give you another 100k -150k or more if iridium. Iridium plugs are also the best option if you are dealing with fouling or deposits.

 

[ASE guy]

2007 Suburban 5.3 with 618K on the clock, on its 3rd engine.







History the top two plugs are NGK platinum have 325K on them and the bottom two AC iridium352K, 25K after I put the plugs in it had a misfire I replaced two plugs with NGK and never changed them back to the AC. The misfire was not the spark plugs a fuel injector was going bad. The NGK have over .100 gap the iridium have .010 over the original .040 gap. The insulator had broken off one of the AC plugs.

He has been saying for the last few years he was going to replace this vehicle so it’s been on life support to just get by. In the last year he’s had to rebuild the transmission the original went 500K. The transfer case just went out along with the differential. Its always ran out well but its starting to show its age. All the pattern issues with the 5.3 are back.



The original engine went 260K he replaced it with a used engine that lasted 150K. I put a GM reman in it that has about 220K on that engine now. He made a bad call on going with a used engine it cost him thousands of dollars to put a used engine in it that already has 150K on it.



I learned my lesson on aftermarket water pumps on this one they ate my lunch. OEM is the only way to go: ). I’ve only charged the AC one time the AC clutch is worn slap out now I took the shim out of the clutch hub we will see how it goes.

It’s been replaced he’s keeping it as a backup. I would have liked to have a fleet of these to work on as its kept me up well. Every 5K its showed up you could set your clock by it. If you want to know I worked on it open the hood.

We just had a misfire on a big block newer 3500 dually. It was in our shop, but I did not do the repair. The owner opted for cheap reman injectors and it still misfired. Shut of the truck and fuel pressure rapidly dropped to near zero. Bought a set of AC Delco brand new injectors and the misfire went away along with the drop in fuel pressure. Imagine that. Bad remans. I almost always recommend new, and sometimes require it for us to do the repair. I figure since we do work labor free, they can opt for the good stuff. To answer your question, I would use OEM, unless he was selling it very soon.

 

[DanielW]

I was always told that newer engines required the iridium plugs, because the spark voltage on newer cars is 2 - 3 times what it was even 20 years ago, and copper and platinum just doesn't hold up. Don't know how true it is, but for the extra $50 or so, why bother putting anything else in.

 

[moresmoke]

I changed the plugs in my Ford 6.8 at 100k. No measurable west on them. Probably could have left them, but then they likely would have been permanently attached to the heads.

 

[Bikinkawboy]

With a good enough ignition system, you could replace a spark plug with a corn cob and it would fire. Newer ignition systems with their high voltage, short rise time spark will fire plugs that an old points ignition with the low voltage, long rise time could never fire.

The rise time is the most important. Like a 5 gallon bucket with a 1” hole in the bottom. Try filling it with a garden hose and the bucket will never get full because it runs out as fast as you can fill it. Take a 5 gallon bucket full of water and quickly dump it into the one with the hole and for an instant the bucket with the hole will be full.

 

[Part Time Pete]

I just replaced the plugs in my 2019 Civic for the first time at 235,000 miles. They're great, but a little spendy at $28 a piece

 

[Hobo,NC]

With a good enough ignition system, you could replace a spark plug with a corn cob and it would fire. Newer ignition systems with their high voltage, short rise time spark will fire plugs that an old points ignition with the low voltage, long rise time could never fire.

The rise time is the most important. Like a 5 gallon bucket with a 1” hole in the bottom. Try filling it with a garden hose and the bucket will never get full because it runs out as fast as you can fill it. Take a 5 gallon bucket full of water and quickly dump it into the one with the hole and for an instant the bucket with the hole will be full.

That's all wonderful if you consider the ignition coils and coil drives bullet prof but they are not and expensive to to replace. The rise time firing line happens outside the cylinder a spark plugs health may have noting to do with it.

 

[William Allen]

According to the date code on the bottom AC plugs, they were produced on 12 Aug 2017 on assembly line 3 at DENSO in Athens, TN. I know this because I work at the factory that produces them.

 

[BarnyardEngineering]

On a Chevy, replace with OEM AC Delco (platinum?) plugs ONLY. Don't fall for the fancy designer plugs.

I've had multiple mechanics give me this advice. One, after I put the fancy iridium plugs in my 2003 Silverado 1500 and immediately started missing and throwing codes. Took it in to the dealer and all they did was put new stock Delco plugs in and it ran perfect for the rest of the time I owned it.

 

[JJay48]

I always use the OEM plugs on a stock engine.

 

[Brown David]

With a good enough ignition system, you could replace a spark plug with a corn cob and it would fire. Newer ignition systems with their high voltage, short rise time spark will fire plugs that an old points ignition with the low voltage, long rise time could never fire.

The rise time is the most important. Like a 5 gallon bucket with a 1” hole in the bottom. Try filling it with a garden hose and the bucket will never get full because it runs out as fast as you can fill it. Take a 5 gallon bucket full of water and quickly dump it into the one with the hole and for an instant the bucket with the hole will be full.

Good analogy.

 

[Texasmark]

2007 Suburban 5.3 with 618K on the clock, on its 3rd engine.







History the top two plugs are NGK platinum have 325K on them and the bottom two AC iridium352K, 25K after I put the plugs in it had a misfire I replaced two plugs with NGK and never changed them back to the AC. The misfire was not the spark plugs a fuel injector was going bad. The NGK have over .100 gap the iridium have .010 over the original .040 gap. The insulator had broken off one of the AC plugs.

He has been saying for the last few years he was going to replace this vehicle so it’s been on life support to just get by. In the last year he’s had to rebuild the transmission the original went 500K. The transfer case just went out along with the differential. Its always ran out well but its starting to show its age. All the pattern issues with the 5.3 are back.



The original engine went 260K he replaced it with a used engine that lasted 150K. I put a GM reman in it that has about 220K on that engine now. He made a bad call on going with a used engine it cost him thousands of dollars to put a used engine in it that already has 150K on it.



I learned my lesson on aftermarket water pumps on this one they ate my lunch. OEM is the only way to go: ). I’ve only charged the AC one time the AC clutch is worn slap out now I took the shim out of the clutch hub we will see how it goes.

It’s been replaced he’s keeping it as a backup. I would have liked to have a fleet of these to work on as its kept me up well. Every 5K its showed up you could set your clock by it. If you want to know I worked on it open the hood.

My 2011 Silverado owner's manual shows the Iridium replacement interval at 100k miles.....along with (synthetic OEM) fluids other than the normal engine change timing which as we all know is shorter.

I traded a 2009 Ram Hemi V8 running a pair of Champions per cylinder, not that easy a changeout for a shade tree mechanic, and the manual change period was 30k miles. One of the reasons I got rid of it.