# Spark Plug analysis **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** sparkplugs\ **Created:** [September 21, 2023, 11:15am UTC](https://community.cartalk.com/t/spark-plug-analysis/193001 "2023-09-21T11:15:08Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Solidventur](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/solidventur/32/8634_2.png) [@Solidventur](https://community.cartalk.com/u/Solidventur)\ **Post date:** [September 21, 2023, 11:15am UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/1 "2023-09-21T11:15:08Z")
Need advice on reading these plugs. from a Sienna with 57k miles on a Toyota 2GR-FKS engine. Some kind of “sandy” deposit on them, what does it indicate? ![IMG_6235small](https://global.discourse-cdn.com/cartalk/original/3X/d/0/d0d0a06a72e3f0e04b295b490071f8aa847db1f4.jpeg) ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 21, 2023, 12:38pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/2 "2023-09-21T12:38:17Z")
Do they all look like this? Any driveability problems? ---
**Author:** ![Solidventur](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/solidventur/32/8634_2.png) [@Solidventur](https://community.cartalk.com/u/Solidventur)\ **Post date:** [September 21, 2023, 12:44pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/3 "2023-09-21T12:44:21Z")
Thnx for the response; no driving issues, only pulled one to check condition before changing all the plugs at the recommended interval (2GR-FKS needs 60k plug interval change since it’s a direct inject engine). I haven’t seen a plug before with this residue on it and wondering if it’s a problem or not. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [September 21, 2023, 1:05pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/4 "2023-09-21T13:05:44Z")
I’d have to guess you have been running some fuel additives lately, possibly injector cleaner. ---
**Author:** ![Solidventur](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/solidventur/32/8634_2.png) [@Solidventur](https://community.cartalk.com/u/Solidventur)\ **Post date:** [September 21, 2023, 1:07pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/5 "2023-09-21T13:07:16Z")
I’ve owned the car for the last 30k miles and never added fuel additives to it. ---
**Author:** ![It\_s-Me](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/it_s-me/32/12660_2.png) [@It\_s-Me](https://community.cartalk.com/u/It_s-Me)\ **Post date:** [September 21, 2023, 1:18pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/6 "2023-09-21T13:18:03Z")
Low quality gas ? ---
**Author:** ![Solidventur](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/solidventur/32/8634_2.png) [@Solidventur](https://community.cartalk.com/u/Solidventur)\ **Post date:** [September 21, 2023, 1:50pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/7 "2023-09-21T13:50:36Z")
Can’t rule it out, I don’t carry a chromatograph when I fill up at various pumps. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 21, 2023, 3:00pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/8 "2023-09-21T15:00:25Z")
I’d pull the rest, if they all look like this I’d assume it was normal and had something to do with the direct injection. If only one, then I don’t know. You might post this on a relevant Toyota forum. ---
**Author:** ![TwinTurbo](https://avatars.discourse-cdn.com/v4/letter/t/8baadc/32.png) [@TwinTurbo](https://community.cartalk.com/u/TwinTurbo)\ **Post date:** [September 21, 2023, 3:01pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/9 "2023-09-21T15:01:02Z")
I’m betting it’s normal for 57k miles on a GDI engine. Why they specify 60k change intervals, more prone to fouling… ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 21, 2023, 3:32pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/10 "2023-09-21T15:32:03Z")
Looks like normal wear. [https://www.austincc.edu/wkibbe/plugchart.pdf](https://www.austincc.edu/wkibbe/plugchart.pdf) Tester ---
**Author:** ![davesmopar](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/davesmopar/32/41750_2.png) [@davesmopar](https://community.cartalk.com/u/davesmopar)\ **Post date:** [September 21, 2023, 5:14pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/11 "2023-09-21T17:14:55Z")
I would stay away from the cheap gas stations if possible… Are you using a higher octane rating then required by Toyota?? Some mid grade and higher grade fuels use more additives than regular grade fuels and that could be what you are seeing **IF** that is what you are running… If you are running a higher octane than required you are basically wasting money… The octane ratings are not an indication of performance, but instead, indicate the fuel’s resistance to pre-ignition. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 21, 2023, 5:23pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/12 "2023-09-21T17:23:08Z")
I highly recommend using Top Tier gas. ---
**Author:** ![Solidventur](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/solidventur/32/8634_2.png) [@Solidventur](https://community.cartalk.com/u/Solidventur)\ **Post date:** [September 21, 2023, 7:25pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/13 "2023-09-21T19:25:50Z")
Thnx for the replies; I’m using various “tiers” of gas, usually from Mobil, Shell, etc., always 85 Octane, never added fuel additives in the 27k miles I’ve owned it. Some charts indicate that the ash is from fuel additives or excessive oil and I was looking for confirmation. I think I’ll just change the plugs and look again after another 60k to see what’s different. ---
**Author:** ![texases](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/texases/32/862_2.png) [@texases](https://community.cartalk.com/u/texases)\ **Post date:** [September 21, 2023, 7:36pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/14 "2023-09-21T19:36:57Z")
“Top Tier” is a specific certification that the gas (regular or premium) contains additional detergents: [TOP TIER - High-quality Fuel Performance Standard - TOP TIER™ (toptiergas.com)](https://www.toptiergas.com/) ---
**Author:** ![Tester](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/tester/32/15976_2.png) [@Tester](https://community.cartalk.com/u/Tester)\ **Post date:** [September 21, 2023, 7:37pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/15 "2023-09-21T19:37:02Z")
It could be from crankcase gasses from the PCV system being burned. Tester ---
**Author:** ![George\_San\_Jose1](https://avatars.discourse-cdn.com/v4/letter/g/e5b9ba/32.png) [@George\_San\_Jose1](https://community.cartalk.com/u/George_San_Jose1)\ **Post date:** [September 21, 2023, 11:05pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/16 "2023-09-21T23:05:17Z")
Definitely an unusual appearance for used spark plugs. I’ve never seen anything like that on any of my cars. Other than the yellow tinge, presumably that’s normal, from sulfur in the gasoline. But none of my cars use direct injection either. I’d guess the gritty, mottled appearance has something to do w/that, the chemistry occurring in the combustion chamber is probably somewhat different with direct injection. It doesn’t look like a show-stopper in any event, just drive on. ---
**Author:** ![circuitsmith](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/circuitsmith/32/40376_2.png) [@circuitsmith](https://community.cartalk.com/u/circuitsmith)\ **Post date:** [September 22, 2023, 12:53am UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/17 "2023-09-22T00:53:18Z")
Nice macro photography! ![DSCN2012](https://global.discourse-cdn.com/cartalk/original/3X/e/e/eeb7604cf5ec8c78855ed717840c5434bdbadeaa.jpeg) ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [September 23, 2023, 6:44pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/18 "2023-09-23T18:44:40Z")
Normal deposits found on spark plugs. These are spark plugs from a Lexus 2GR-FKS engine, 59,900 miles. ![20230923_103712](https://global.discourse-cdn.com/cartalk/original/3X/a/f/afdf5646127e2f130284ff6464c82d45771645b1.jpeg) ![20230923_103719](https://global.discourse-cdn.com/cartalk/original/3X/9/f/9f4114086e7ff0d530e11559e2db9acc9e40be76.jpeg) ![20230923_103813](https://global.discourse-cdn.com/cartalk/original/3X/2/c/2c23f482024e74d239ca4def0bb827b01249fe08.jpeg) ---
**Author:** ![Solidventur](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/solidventur/32/8634_2.png) [@Solidventur](https://community.cartalk.com/u/Solidventur)\ **Post date:** [September 23, 2023, 6:56pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/19 "2023-09-23T18:56:26Z")
Thanks for these pics, the electrode wear looks similar to mine. I’ll compare them when I pull all of my plugs. ---
**Author:** ![db4690](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/db4690/32/2583_2.png) [@db4690](https://community.cartalk.com/u/db4690)\ **Post date:** [September 23, 2023, 7:56pm UTC](https://community.cartalk.com/t/spark-plug-analysis/193001/20 "2023-09-23T19:56:20Z")
> [@Solidventur](#): > > I’m using various “tiers” of gas, usually from Mobil, Shell, etc., always 85 Octane Where I’m at, 87 is the lowest quality gasoline available, afaik I don’t know the year of your Toyota Sienna, so I looked up the 2020 Sienna owner manual, which has the 2GR-FKS engine here’s a cut-and-paste from the specifications section . . . Octane rating 87 (Research Octane Number 91) or higher [Next page](https://community.cartalk.com/t/spark-plug-analysis/193001.md?page=2)