2021 3.6 MT Detonation

[John_81583]

Hi,

I have a 2021 Gladiator overland MT 3.6 with engine detonation. I've owned it for a year without issues. Previous fill up at Costco with 87 caused real bad detonation. Every time I would accelerate low speed 3 or 4th gear it would sound nasty LOUD and was able to replicate it every time I tried. I went and dumped a bottle of Lucas octane booster, Lucas injector cleaner and topped off tank with 6 gallons of 93 octane. It went away slowly after riding for a bit to clear the lines of bad fuel. Fast forward I went ahead and filled up today full tank with 87 BP station. Occasionally s heard a very quick and short detonation. Had to lower music and a/c to hear it carefully.

Now I know 87 is the recommended fuel per the owners manual. However, after owning this Jeep for over a year on a steady diet of 87 octane. Why would it start doing this? Does it take a few tanks for the ECM to adjust timing back to 87 after running the boosted octane gas? All though its nearly its very hard to replicate or hear with the fresh 87 fill up. Definably something's either wrong with the timing. Or my area just happens to have poor fuel lately. Jeep has 13k miles with 1k miles on the current engine oil (Amsoil Signature Series 0w-20/ filter).

I drive roughly 70% highway 20 miles a day in the Twin Cities It's been almost a year of trouble free engine with 87 fuel.

I wouldn't touch that octane booster and injector cleaner on a new vehicle, maybe one with over 150,000 miles, that could be the issue, or a case of bad gas like Bill said, could've had some water in it.

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[onewhippedpuppy]

Why can't people accept that it's not a killer, especially "occasionally".
The dealer is going to refer you to the book and say "ignore it, it's normal"
99% don't give any ping, but the few that may - and I say may as it's not been decided that ALL are true detonation, it's not something to lose sleep over.

I guess, I post this again from a GM engineer who is responsible for the Northstar engine -

Absolutely temperature IS a factor! Cool engines do not detonate. Only hot engines (fully warmed up, and I don't mean "coolant temperature" I mean the entire engine) warmed or above normal.
If it's not reach normal operating temperature and been there for a while, it's not detonation.

......... has anyone given any thought to other factors? Crap oil that's not up to modern specs can cause a ping.

Sorry but the “it’s a Jeep thing” excuse is total BS. There is no excuse for a nearly $60k truck to be making buzzing noises under normal driving conditions that are annoying enough that a number of people have complained about it. Even if it’s not catastrophic, it’s still not ok.

Back on topic, I will try 91 octane the next time I’m empty and see what happens. What the hell, I’ve tried everything else.

 

[NachoRuby]

Sorry but the “it’s a Jeep thing” excuse is total BS. There is no excuse for a nearly $60k truck to be making buzzing noises under normal driving conditions that are annoying enough that a number of people have complained about it. Even if it’s not catastrophic, it’s still not ok.

Back on topic, I will try 91 octane the next time I’m empty and see what happens. What the hell, I’ve tried everything else.

No one said it's a jeep thing. His reference was from general motors. If your rattle is the same as mine, 91 octane won't help. Tried that.

 

[onewhippedpuppy]

No one said it's a jeep thing. His reference was from general motors. If your rattle is the same as mine, 91 octane won't help. Tried that.

My response was to his comment about it not being anything to lose sleep over. When my nearly brand new truck sounds like my old 1979 Silverado when the speedometer cable was going bad, that’s not acceptable. While mild detonation may not be fatal to a normally aspirated engine it’s also not a normal operating condition.

 

[Nuclear_Inc]

Just wanted to update everyone,

So I called my dealership for the TSB mention previously. Basically told me you can bring it in but if theirs no CEL your waisting your time because they can’t do anything without one. So I decided to try to figure this out on my own.

Ran one can of Amsoil power foam cleaner through throttle body. Although it did smoke a lot and burned carbon light pinging continued. So I dropped some Amsoil fuel system cleaner and a can of their octane booster. Then went and topped of current 87 tank with 8 gallons of premium 92 oct. Drove it for 10 miles get the fuel system mixed and the lines full with treated gas. Problem basically has gone away. Now this is completely BS we have to deal with pinging because 5.3 in new silverados are also 11:1 compression with no issues. I’m not of fan of paying premium prices at the pump. So I can I’ll try 89 mid grade gas next fill up. Like many ppl I have relations with Jeep cares for past issues. I’m sure I can call and ask for the TSB regardless of Jeep is free of fault codes. Anyways I’m not sure that TSB really fixes anything. So I’m just going to live with the ping or try 89-92 fuel for the rest of my ownership.

 

[Whitewilly1le]

Subbed for updates. In the same boat

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