bclexus

@jgscott - Jamie, How often do you replace the light bulb in your refrigerator?

jgscott

iTrader: (1)

I lack the ability to have multimeter reading eyes like some of you do, to read resistance without a multimeter. Sorry.

bclexus

Jamie - The resistance in modern day resistance type spark plugs has a built-in resistor of ~ 5k to 7k Ω to attenuate the ignition noises generated during spark emission so it doesn't interfere with radio reception or communication equipment. The video you posted displays measuring this internal spark plug resistance, which presents absolutely no affect whatsoever on the spark plug's ignition performance ability. Zero... It's totally meaningless in terms of engine performance or fuel economy.

The video you posted also displays another meaningless detail - that full continuity (near 0 Ω) is needed between the spark plug's shell/threads and the side ground electrode. Nothing more, nothing less. Again - it has no value, it's pointless...actually senseless!

The tail of the tape is this: Measuring a spark plug's internal resistance is totally meaningless to attest its ignition performance ability. Measuring a spark plug's continuity between shell/threads and the side ground electrode is totally meaningless, the same as measuring the continuity of a wire conductor that is 3 inches in length - it will always measure 0 Ω.

jgscott

iTrader: (1)

Oh no, no, and no. I am not going to start training class here. I have researched this quite a bit. Best you talk to NGK, or Denso or Champion Engineers. They have all redesigned and changed Core tech over years, for the very reasons that Core has a lot to do with plugs. I don't design them. Does anyone here? There is a reason why FAKE plugs fail when the authentic ones do not. They both have Cores.

Like I said it is the GS owners choice.

bclexus

Jamie - Please don't start training class, especially after you posted that meaningless video! Because you seem to be quite an expert at not knowing what you're talking about.

JUTMSS32

Agree 100%. This is a no brainer for me.

While I do agree that 60k for a spark plug change is way less than what the spark plugs are good for. I think you can go 100-150k safely with a quality set and in most other circumstances, I would do just that. In this case, changing them at 60k keeps you in compliance with the Lexus Emission Control Warranty. If you're somewhat mechanically inclined and can change them yourself, why not? It only cost about $120 tops for 6 Denso spark plugs and about an hour of your time. Sure, there are usually 1 or 2 plugs that are hard to get to, but with some research on the forums, Google and Youtube, you can usually find easy ways to navigate this issue.

What I wouldn't do is risk going over 150k miles on a set. The failure of 1 bad plug in the set could result in having to replace catalytic converters, O2 sensors, coil packs and of course a new set of plugs in an attempt to rid the car of all the codes that may result. There's too much to risk for me and unfortunately I went through this with my last car, Camry XLE V6. I changed my first set of plugs at 100k with no issues. The second set, (OEM Denso) I had one fail and start misfiring at about 180k on the set, 280k on the car and went through all of the above to get rid of the codes. My mechanic only changed one plug and coil pack and my local exhaust experts replaced 2 converters and some O2 sensors. I eventually replaced all 6 plugs myself but traded the car in at about 307k to get the GS.

Nusbaum

Regardless of your decision on plug maintenance, checking the plug tubes for oil pooling is good practice. While changing plugs on my SC430 I found two tube seals leaked significant oil into the tubes. No visible valve cover leak. Not sure when the seal leak would have caused problems, but would not have discovered it without the 100k plug replacement. If you normally check tubes for leaks change plugs on whatever schedule you want, otherwise you might not catch this potential problem.

jgscott

iTrader: (1)

The Title of this Thread is - Conflicting info on Spark Plug change intervals? Do I need to change at 60k miles?

Lexus says YES.
Denso says YES

You can do whatever you want with "your" Lexus, owners.

This is the 2nd and Last post of fact info I'm going to post. Like I said before, I have already spoken to both Denso, and NGK, in the past due to running n/a stock engines and FI like Nitrous. For my own personal choice. There is Zero conflict from Lexus, Denso, or NGK. Maybe posters, but not their experience in Development Engineering and Design Lab.

Sent to me by DENSO - Denso Spark Plug Training Manual. vs CL Members post Narratives.

https://www.denso.com/global/en/prod...f/t-manual.pdf