Do your 3rd Gen. valves float on 87 octane fuel ?

... ^^^ ... Ok ... thanks .... in the shop it will go this week for an oil change (my cost on oil change at 3000 miles) and checkup for this and transmission.

 

I don't have a third gen so I'm no expert but my another member was telling me that these v6 atkinson cycle engines can make what sounds like pinging on acceleration. However the pinging noise is the injector cleaning part of the cycle.

 

I mostly agree with this. My problem is that it should be plenty happy on 87 with 10% corn fuel.... I'd think that ethanol would even slow down the burn and help the issue as it has less energy per volume than gas. I don't think humidity would have this effect either.

Spark knock, pinging, detonation, preignition can be caused by too much compression, lean fuel mixture, too much heat in the combustion chamber, or too aggressive ignition timing. Sounds like Toyota should take a look.

Maybe it could be where you are getting your gas if you consistently go to the same place.

 

...^^^... Yes, I go to different places for gas now.

 

My truck runs better with premium. The low end torque seems to be smoother and more linear. With regular, until you reach 4K rpms, the truck is a dog. Premium helps with this.

 

I've ran all from super clear ethanol free 91, to E10 91, and regular 87. I have not felt a discernable seat of the pants difference, except the super clear gave me a couple more MPG's

 

I hear a pinging from my engine, but I am fairly certain it's the injection system. I agree it must be something to do with the acoustics of the engine bay and insulation that makes it so audible. It had me very worried for awhile, but the more I listen to her the more I think it's just the way it goes.

 

Been running 87oct in mine since Feb, no pinging, no problems at all.

 

It really is.
http://fuelschool.blogspot.com/2009/02/phase-separation-in-ethanol-blended.html?m=1

http://www.fuel-testers.com

 

I should not have used that old fashioned word "pinging".

My sound is more like a "rattle". I will go with 89 and up and try to stay away from any amounts of ethanol. Some really good ideas from you guys.

 

To not use high concentration ethanol. I don't know why they advise against it. Perhaps the tuning and engine can't run properly. It is a dry fuel that can carry lots of moisture, it might have something to do with the DI and corrosion. I honestly don't know for sure though.

 

Too much denaturant?

 

I live I Atlanta and on hot days I also experience this. I'm at a low altitude and it's hot. I can tell premium runs a better for hot days. My second gen pinged really bad here and I always had to run premium. Now when I'm up in North Carolina in the mountains 87 seems to work fine.

 

This engine was in a Lexus before I believe or heavily based off a Lexus motor designed for premium. I've experimented as well and premium seems alot better and less low RPM lugging. I hate spending more on fuel though

 

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I am in ATL and my experiences are the same with different Tacoma's and in NC too.

IIRC, my 2004 Gen 1 (V-6) did not ping though.
.

 

I think you'll find this interesting
https://generalaviationnews.com/2011/06/26/vapor-lock-ethanol-and-ultralights-2/

 

Valve float

 

I don't know enough about this subject to offer an opinion.

 

Mine does this too. Not temp specific. Situation specific. Right at shift. Pretty sure it's injector noise.

 

This is my baby and it has a boxer engine on it, R1150R, this thing make some pinging popping, you would swear it is coming apart at the welds. It's a 2004 and has 68k miles on it. One day I put 87 octane in it by mistake and it seemed to calm down. I went back to 91 octane, however, knowing what I do about compression and ignition points. That said...I think I will get myself another beer!