100K sparkplugs at 40K

[SwampSurvivor]

I've had a few vehicles with the so-called 100k plugs look worse than that at 50k. The worst was my Taurus at 40k ... I'm not sure how it even fired - the plats were wore to nothing.

I then replaced with copper and changed them every fall.

 

[GMBoy]

Plugs are just too cheap to stretch to 100k miles when they can cause more expensive issues such as strain on ignition coils, ruining aluminum heads etc. I also have not seen many plugs go 100k miles...had to change the plugs in 2 CTS's (both DI) due to misfires at under 50k miles. I had posted about this.

Do people get 100K miles on plugs? They certainly do and sometimes more. But there are many who cannot get past 50-70k miles either so it depends on a lot of factors just when you need to change them.

AS for the poster, looks like too many fuel additives and the plug is too cold to burn off deposits. Go back to the stock plug heat range and you can (as others also said) gap fine wire plugs.

 

[Eddie]

These plugs seem to have more crud on them than normal. This is partly due to the plugs running colder than recommended so, the crud doesn't burn off. I also wonder if part of the problem is the use of mediocre gas i.e. not a name brand. I've know several people who have gotten 100,000 + miles on a set of plugs and the plugs looked like they were good for another 50K.

 

[punisher]

We should hve a "30K plug changed at 120K" mile thread.

Most productive tuneup ever on a '80 C1500 with a 305. 2 plugs had almost no ground electrode, still fired. Only thing that caused a missfire was ash deposits finally closed the gap on one plug. Inside of distributor had "nuggets" rotor knocked off from contacts in cap over the years. HEI got a little more, not much more, but a little more respect from me that day. Any HEI I had seen before, in that bad a condition, had a melted carbon button/rotor on it.

Thank the maker it didn't have aluminum heads as I would have had to quicksert 8 holes that day.

 

[CBR.worm]

I'll answer a couple of questions, I didn't expect so many responses so fast.

The car has 135K miles on it. It has almost no city miles (I have no city). Most of the miles are highway, as much as possible in the mountains with or without a trailer. Some of the miles are from track days. At 80mph in top gear it is just over 3K, the engine rarely sees anything below that if I am moving. This cars sole purpose for me is for fun (even though it is too heavy, too soft, too slow and has poor brakes). For slow/local trips with wife/kids I use the FX...Which is also too heavy/slow and of weak brakes. It is not too soft though.

No fuel additives, only 93 Chevron or Mobil (they are near my house). There is a warning label not to use anything other than premium fuel - if you do, only enough to get you to another station. Any deposits are a result of Chevron/Mobil 93 and Mobil 1 0w40 that sneaks through.


Colder plugs are due to pinging - it helps a little, the owners manual recommends one range cooler if it will see high speeds and minimal idle time.

The plug box says not to gap, that it will damage the electrode. The paperwork that comes in the box says if you gap them, the electrode will snap, so I don't.

All six plugs look virtually identical, they each have their own coil (coil over plug) so I doubt it is wasted spark - but it could be. I bought this car new, every plug that has come out of it has looked about the same. Typically I run 45K, this time I ran 40K because I was due for an oil change, PCV valve, an evap valve and another set of belts anyway. Might as well do it all at once.

These are NGK LFR6AIX-11 'Laser' Iridium plugs.

I do need a tune. The car runs rich 100% of the time. Spending time and money on the dyno are not high on my list of priorities right now.

 

[friendly_jacek]

Originally Posted By: CBR.worm

These are NGK LFR6AIX-11 'Laser' Iridium plugs.


LOL, I was wrong on city driving but correct on NGK plugs. I recognized them by the tapered ground electrode.

You are mistaken if you think the NGK IX series of iridium are long life plugs or "laser" ones. They are not, as they have no precious metal on the ground electrode, and are thus performance iridiums with no long life benefits compared to standard plugs.

Autolite XP5325 will give you iridium finewire with long life platinum ground electrode. Best bang for buck. I use it in my Toyota.

 

[SteveSRT8]

Originally Posted By: friendly_jacek
Autolite XP5325 will give you iridium finewire with long life platinum ground electrode. Best bang for buck. I use it in my Toyota.


Yep, the 'hybrid' NGK's are generally spec'd for 100k miles replacement in many cars.

I have run them much longer, they are a great design.

 

[artificialist]

My 2003 Saturn ION was built with 100,000 mile double platinum spark plugs, but I had to replace them at 60,000 miles. ACdelco quit making double platinum plugs for that car, and I had to use single electrode Iridium plugs.

What is also strange was that my mom's 2005 Jeep Grand Cherokee was built with NGK Copper plugs that were meant for replacement every 30,000, but they were okay for 90,000 miles. I put Autolite Double Platinum plugs in there because that was all I could find.

I rarely ever see spark plugs fail close to when the manufacturer says they will. The only car I can think of that does have plugs fail when expected is the Toyota 1MZ variant with waste spark ignition and weird looking Denso plugs with 2 grounds.

 

[OVERKILL]

The deposits may just be due to the colder plugs then.

 

[bowlofturtle]

maybe i should consider pulling out mines... My 05 sedan is @ 67k now. Nissan recommends the plugs at 105k. I've had a spare set of plugs since 35k, (ebay set of 6 for $15) I wanted to pull them at 80k but i'll just do them sooner.

Hopefully nothing needs to be removed. I can see some of the coilpacks

 

[CBR.worm]

They are pretty easy compared to V6 FWD cars. On the driver's side, the air intake tube and airbox can be taken off giving clear access to all the coilpacks on that side. The passenger side is pretty accessible. The hardest part is that Nissan bundled a wiring harness straight over the top of both sets of coilpacks that is pretty tight.

 

[CBR.worm]

Don't be tempted to move the throttle butterfly, if you do there are steps that need to be taken to recalibrate it.

 

[yonyon]

That picture makes it look pretty easy to get to those plugs. I think I'd be much more confident in changing those plugs out than trying to get the wackadoo oil dipstick back in its home. It's a very complex motion that requires practice, isn't it?

 

[GMBoy]

Originally Posted By: CBR.worm

Don't be tempted to move the throttle butterfly, if you do there are steps that need to be taken to recalibrate it.



Throttle body needs cleaning

But yeah - don't move it! Spray all around it atleast to dissolve that crud.

 

[GMBoy]

Not all NGK Laser Iridiums are long life...they advertise one model performance line for 30k miles.

These are long life:
http://www.ngksparkplugs.com/products/spark_plugs/laser_iridium.asp?mode=nml

These are not:
http://www.ngksparkplugs.com/products/spark_plugs/iridiumix.asp?mode=nml

 

[CBR.worm]

Yeah, the dipstick is dippy.

And there is always sand sitting on the flange that the dipstick hole is in, I know that every time I check my oil some sand surely falls in.


It is pretty easy to get to the plugs, getting the wiring harness to move out of the way is challenging. I end up unbolting a couple of the harness supports and disconnecting a couple extra connectors, and I still end up having to push it aside with more force than I would like.

 

[joaks]

Originally Posted By: GMBoy
Not all NGK Laser Iridiums are long life...they advertise one model performance line for 30k miles.

These are long life:
http://www.ngksparkplugs.com/products/spark_plugs/laser_iridium.asp?mode=nml

These are not:
http://www.ngksparkplugs.com/products/spark_plugs/iridiumix.asp?mode=nml


The Laser Iridium are, the others are called "IX".

 

[friendly_jacek]

Originally Posted By: joaks
Originally Posted By: GMBoy
Not all NGK Laser Iridiums are long life...they advertise one model performance line for 30k miles.

These are long life:
http://www.ngksparkplugs.com/products/spark_plugs/laser_iridium.asp?mode=nml

These are not:
http://www.ngksparkplugs.com/products/spark_plugs/iridiumix.asp?mode=nml


The Laser Iridium are, the others are called "IX".


This is exactly the point BMBoy and I are trying to make. The OP uses IX plugs that are "short-life" rather than long life, thus the whole thread is misleading in the first place as the OP doesn't use "100K" plugs.

 

[joaks]

Originally Posted By: friendly_jacek
Originally Posted By: joaks
Originally Posted By: GMBoy
Not all NGK Laser Iridiums are long life...they advertise one model performance line for 30k miles.

These are long life:
http://www.ngksparkplugs.com/products/spark_plugs/laser_iridium.asp?mode=nml

These are not:
http://www.ngksparkplugs.com/products/spark_plugs/iridiumix.asp?mode=nml


The Laser Iridium are, the others are called "IX".


This is exactly the point BMBoy and I are trying to make. The OP uses IX plugs that are "short-life" rather than long life, thus the whole thread is misleading in the first place as the OP doesn't use "100K" plugs.


Oh, my mistake. I saw where the plugs were called laser iridium and thought that was the correct title. You are correct.

 

[Vikas]

I think those Nissan engines are hard on the plugs. I took the original set from 3.0 engine and the gap had more than doubled at 140K. *HOWEVER* the car was running fine and new spark plug made no difference in the running of the engine.

I suspect your spark plugs would look not so good at 100K but they would still function fine at that age. I do not believe you will notice any difference when you put the new ones in.

- Vikas