Examining used spark plugs

[FordSVTGuy]

Use your expertise to help me learn from these used spark plugs. What jumps out at you? I don't see excessive deposits or gunk on the electrodes but they are fairy dirty. Just pulled them from my daughter's 2016 Passat with the 1.8T engine. They are NGK by say Volkswagen on them too. This is at 82,000 miles and I'm not sure if they were ever changed before. My guess is no. I bought this for her used at about 70,000 miles. I replaced with identical aftermarket NGKs.

 

[JohnnyG]

Pretty typical, normal wear and deposits. Nothing remarkable and nothing to fix.

 

[hemitom]

Pretty typical, normal wear and deposits. Nothing remarkable and nothing to fix.

Bang on advice ! replace as you did and move along !

 

[KrisZ]

Mine looked far worse, but still there was no performance issues at all.

These days there is very little you can tell from spark plugs and even less you can do about it, if something looks off. Back in the carb days it mattered and you could adjust the mixture to your linking, these days no such thing is possible.

 

[Boomer]

VW recommends 40,000 mile change on plugs. Mine get done at that limit.

 

[Lubener]

https://honda-tech.com/forums/forced-induction-16/***-basics-reading-spark-plug***-3063102/

 

[martinq]

It's hard to tell from the pics, are these single or double precious-electrode (platinum, etc)?
NGK part number?

 

[FordSVTGuy]

It's hard to tell from the pics, are these single or double precious-electrode (platinum, etc)?
NGK part number?

NGK Laser Platinum #06k905601dk2

 

[FordSVTGuy]

VW recommends 40,000 mile change on plugs. Mine get done at that limit.

At 40,000 miles, how do the plugs look?

 

[martinq]

NGK Laser Platinum #06k905601dk2

Laser Platinum are dual electrode, really good stuff.

I would run those out to past 100k I think and running some Fuel System Cleaner will help clean up the injectors, combustion chamber including the spark plugs. Valvoline Restore and Protect might also help if you're having any misfire or oil consumption.

 

[FordSVTGuy]

Engine is running great, but I do want to run some fuel system cleaner for the injectors…

 

[Oliveoil2]

Engine is running great, but I do want to run some fuel system cleaner for the injectors…

If that’s what you want to do, do it during the final 2 fill ups before an oil change. That way it gets all the chemicals out with the old oil. But seeing your plugs I wouldn’t. They are burning beautifully. You have a keeper there.

 

[TheMAN]

NGK Laser Platinum #06k905601dk2

that's way too many miles for platinum plugs, especially in a turbo engine... you can see how worn/rounded the electrodes are... with iridiums that's OK with that many miles but you'll end up with the same looking plugs if you get them to 100k, which is way too much on a turbo engine

 

[TheMAN]

Laser Platinum are dual electrode, really good stuff.

I would run those out to past 100k I think and running some Fuel System Cleaner will help clean up the injectors, combustion chamber including the spark plugs. Valvoline Restore and Protect might also help if you're having any misfire or oil consumption.

not on a turbo engine it's not

combustion pressures and temperatures are much higher, and that requires higher spark voltages... higher spark voltages + heat + pressure = faster wear

these OEM denso iridiums came out of a toyota 1ZZ-FE at 105k miles.... USDM recommended intervals is 110k... it ran fine but after seeing that, it's way too many miles for it... even 100k is stretching the limits of what they can do with the platinum ground electrodes that are basically gone, in a bone stock non-turbo engine!

 

[TheMAN]

At 40,000 miles, how do the plugs look?

stick to the 40k intervals for those dual platinum plugs, no more... if you want to run them to 75 to 80k, then step up to OEM style NGK laser iridium plugs, which are iridium tipped, with platinum tipped grounds

 

[SC Maintenance]

Looks OK. Color is decent, maybe a bit dark, center electrode is still the right shape. I can see why VW recommends 40K changes, my Nissans look better at 105K.

 

[sru1436]

https://honda-tech.com/forums/forced-induction-16/***-basics-reading-spark-plug***-3063102/

This is awesome, thank you. I have a few carburetored engines in my stable.

 

[martinq]

It's not

not on a turbo engine it's not

combustion pressures and temperatures are much higher, and that requires higher spark voltages... higher spark voltages + heat + pressure = faster wear

these OEM denso iridiums came out of a toyota 1ZZ-FE at 105k miles.... USDM recommended intervals is 110k... it ran fine but after seeing that, it's way too many miles for it... even 100k is stretching the limits of what they can do with the platinum ground electrodes that are basically gone, in a bone stock non-turbo engine!
View attachment 351925View attachment 351926

It's not how they look but how they perform. I would run the first set until I know there is a consistent performance issue and use that for a point of reference.

I "need" to change plugs in our Nissan 1.8 from 2010 with 150k on them but it is currently a non issue. I'll keep it in mind until I have an ignition related symptom which should be soon? Surely before 200k I would think.

 

[TheMAN]

feel free to burn out your coil packs and replace them because they "performed" well past what most manufacturers calls for, for a specific engine application... even following the book to the T, you can run into problems, all because the insatiable desire for extended maintenance intervals in the US, as that helps drives sales... it's not unheard of from people with toyotas with coil pack problems because they changed their plugs at 110-120k

naturally asperated low compression engines are very easy on spark plugs... high compression or forced induction, not

 

[martinq]

feel free to burn out your coil packs and replace them because they "performed" well past what most manufacturers calls for, for a specific engine application... even following the book to the T, you can run into problems, all because the insatiable desire for extended maintenance intervals in the US, as that helps drives sales... it's not unheard of from people with toyotas with coil pack problems because they changed their plugs at 110-120k

naturally asperated low compression engines are very easy on spark plugs... high compression or forced induction, not

I'm OK with replacing plugs, coils and injectors after 100k, it's not that big of a deal. I'll do what needs to be done.