Spark plug deposits

Greetings!
Hey, does anyone have an idea what can cause such deposits (see the pic). I have the similar situation with spark plugs of #1,3,& 5th cylinders (I sometimes have a misfire at the cold start on those, P0301,3,5).
All the spark plugs are a half-year-old (4,000 miles used)
Denso (3421) SK20HR11 Iridium as per spec.

Also, FYI, yesterday, I did a compression test, and all the cylinders showed from 165 to 177 PSI which is totally good per spec.
Thanks

 

Spark plug part number?

 

Denso (3421) SK20HR11 Iridium (per spec)
Newly installed 6 months ago or 4,000 miles ago.

 

Do you have a specific place you fuel at all the time?

 

Where do you live?

 

SF Bay Area, CA

 

Mostly at Costco. Interesting why it impacts only 3 cylinders.

 

Maybe a little salt deposits?

 

I replaced those spark plugs, so I'll try to scrab the stuff and see if it will dissolve in the water?! Or will go down...

 

Which place are you comfortable to fuel up with?

 

The pics look like ash to me. Do you have any oil consumption issues?

 

BP 93 octane non ox if possible otherwise 91 non ox.

 

I think costco is rated top tier, just curious whose additive packets they use.

 

It does not really look like ash to me from a closer look, plus I'm not sure I have an oil consumption issue... The level is good, I don't have a blue-ish smoke from the exhaust... Although, I started to notice a gasoline smell from the oil fill cap.

 

Copy

 

I'd send a oil sample to Blackstone for a quick check-up.

Compression done on cold or hot engine?

Lot of short trips?
Engine reach OP temp regularly?

 

https://www.onallcylinders.com/2012/12/20/reading-101-how-to-read-your-spark-plugs/

 

On hot engine!

 

The majority of trips are long-distance (~200 miles one way).

 

Yes!

 

Thanks. Yes, maybe it is the ash deposits...

 

Will try to do it!

 

Were the plugs tight when they came out?

 

Hard to say... Could they loosen up? I mean, I did tighten them myself to 15 ft-lbs 6 month ago.
I don't believe they were loose yesterday when I removed.

 

Are those internet plugs from a reliable source? There have been a lot of issues from internet sales of plugs being fake plugs, look a likes made from inferior material and causing missing problems. Did you change them for time/wear or did you have the missing issue before you changed them? Toyotas are very fussy about plugs. I don't know if you know this or not but worth mentioning anyway. Go strictly by the number in your owners manual. Do not use a cross reference plug. If the store does not have either the right Denso, or the right NGK number go to another store and get the exact plug number or you will more than likely have miss fire issues. You may be savoy about Toyota and Sparkplugs but just throwing this out there for anyone else trying to get a good deal on the internet and end up getting a inferior plug. They look good on the outside, and they even come in stock manufacture boxes. So don't get fooled by price.

 

Plug looks like some images I've seen for lean AFR conditions. And it's happening to multiple cylinders on one side of your engine... possibly a fuel pressure issue.

 

This will solve the problem and a host of others too. It is far more cost effective than any other fuel treatment out there, meant for boats but I use it on all my engines. It decarbonizes, stops the breakdown of methanol and allows the engine to burn fuel hotter to get rid of those deposits. Luck.

$26 STAR BRITE Star Tron Enzyme Fuel Treatment - Concentrated Formula 32 Ounce - Treats 512 Gallons,Blue

https://www.amazon.com/Star-Tron-En...id=1605532716&sprefix=startron,aps,240&sr=8-6

 

I concur.

The misfire codes are due to another cause. There's not enough deposits on that plug to keep it from firing. Sparkplugs typically will get some deposits, we just don't take them out every 5K miles to see them.

 

Very possibly especially since its bank specific. Good thinking.

If the OP has a scan tool he can check fuel trims and compare.

 

Thanks, I believe I purchased those as per spec from auto zone, and installed when I just got the truck 6 months ago.