2022 Gladiator (3.6ltr V6 GPEC 2) pinging at very low throttle settings

[ShadowsPapa]

All that pre-detonation implies is that the detonation is occuring BEFORE the sequence related to the ignition timing marks on the crank complete the appropriate denotation sequence in the cylinder/s!

LOL - not possible because of what detonation is.
Detonation can ONLY happen after the spark ignites the charge. So there's no way to have any such thing as "pre-detonation".
Pre means before - so that term means before detonation.
There simply is no bloody such thing as pre-detonation. No way, no how. It's not a thing.
I've studied this for years and have written articles and referenced engine designers in my writing. There isn't such a thing. it's a made up term.

When fuel air explodes too early in an engine, it causes a loud pinging noise.

It doesn't explode - it's a controlled systematic burn.

1. high compression - Jeep increased the compression ratio in the 3.6 litre engines from 10.5:1 to 11.5:1...and that makes them prone to this issue

That's the static theoretic compression ratio at 100% pumping efficiency, valves totally closed at BDC and valves totally closed at TDC.
Running, it's usually well under that in reality because the intake doesn't close at exactly BDC and the exhaust doesn't fully close at TDC.
Dynamic compression pressures are far more important.
They can release some of the compression pressures by changing valve timing, and, by using low lift at RPM below about 2800 RPM, you can't fully fill the combustion chamber. So you won't get that 11.5:1 number.
Depending on the cam grind, cam timing, LSA, and other factors, you may end up well under that, or with valves at full lift, even over 100% pumping efficiency.
I have built quite a few engines, and even dealt with the factors that cause detonation (again, that pre-detonation term is a total joke), used various factors to control detonation.


Yeah, we have to be picky here because the causes and results are different. You don't use the same methods to resolve detonation as you would preignition.
It matters very much. No real mechanic or tech that knows anything about either would confuse the two. Only journalists who write about cars and engines but really know nothing created that term not understanding what they were hearing about.

PREIGNITION is very different. It is absolutely caused by something igniting the charge BEFORE the spark, thus the PRE prefix - BEFORE IGNITION - BEFORE SPARK.

Detonation is caused when the compressed and burning fuel charge flame front pushes against the unburned charge in the chamber, raising the pressure and heat on the unburned fuel to the point of self-ignition.
So now you have TWO flame fronts, both burning, not exploding, and the hit each other, blowing away the boundary layer protecting the top of the piston, allowing the full heat of the burning charge to hit the piston top, causing melting or breaking from the force of the colliding flame fronts and intense pressures.
Higher octane fuels resist self-ignition. The molecular structure resists self-igniting under intense heat and pressure. It burns the same, same energy content, same burn speed and so on, it simply resists DETONATING or self-igniting. That's it.

I could post all of my articles on the topic, but most will still insist they know more or better.

DETONATION has no "pre" prefix on it! Detonation is detonation. That's it.

I can post a ton of materials - including this bit from a detailed study and explanation of each - look at the terms!

This is from a GM engineer who actually designed engines and wrote on the science of combustion -

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[JTGuy]

If I had this issue and the dealer was just dragging his feet on it I would fill it with premium and drive it like I stole it, hard and fast. Clear it out or send
it.

 

[ShadowsPapa]

If I had this issue and the dealer was just dragging his feet on it I would fill it with premium and drive it like I stole it, hard and fast. Clear it out or send
it.

First thing he needs to do, if you have actually read the "information he found" is to trash that information as it's leading him down some very wrong paths.
For example - this is totally weird, and wrong -
>> Another alternative can be "advancing the spark timing". This will reduce the ignition lag and hence the knocking. <<

So, advancing the timing prevents knocking? LOL

And this -
>> Thus before the actual start of the primary flame front, a secondary flame front starts travelling in an opposite direction, cause a collision and hence knocking. <<
No, that's sort of addressing preignition and because the spike of pressure is not as high, and is spread out over a longer time, there's not a knock, but a chance of burning a hole in the piston.

He must have found that on an AU Jeep forum or something.
His description, and then the write-up he "found" after that just makes little sense.

This image also makes me wonder about a couple of things - like oil consumption with that one cylinder - read it carefully -
Oil level low (not normal)
#3 had oil on top of the piston - but minimal carbon on any of them.

So low oil level, oil on number three, but no appreciable carbon on those three.

 

[JTGuy]

Absolutely right. it's like the dealer is throwing out a word salad and hoping something sticks to the wall. How about doing a compression test on all 6. If there is oil in #3 something isn't right there. A good test drive with a real mechanic and some equipment would help.

 

[ShadowsPapa]

How about doing a compression test on all 6. If there is oil in #3 something isn't right there.

Leakdown test better, compression test at the least.

Since they state in black and white - "oil on top of the piston" and no appreciable carbon, that's suggesting at the least that there's excessive oil on #3.
Were they not at the very least curious?
If I pulled the plugs out of any of the engines of my vehicles and determined there was oil on top of one of the pistons, that's the first thing I'd do next to try to figure out - why? Fluke, or something wrong?

 

[JTGuy]

It's rings or guides.

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