Am I the only one having spark knock issues?

[jebsurf]

Ok so I'm having some serious spark knock issues. Of course it's at its worst when I run reg fuel. I seen a video about Ripped upgraded coils and how much they help with ignition, but is anyone else having this issue?

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[Renegade]

Yes
https://www.jeepgladiatorforum.com/...with-misfire-issues.24853/page-78#post-581426

 

[jebsurf]

Thank you

 

[Jeeperjamie]

You should of been running regular fuel from the beginning, the JT isn't set up for higher octane fuel.

 

[DanW]

A healthy Pentastar shouldn't be knocking or pinging on regular 87 gas. I'd take it in and try and get them to do something about it. Also, I'd run a newer SP GF6 oil.

 

[MrZappo]

You should of been running regular fuel from the beginning, the JT isn't set up for higher octane fuel.

What does "set up for higher octane fuel" mean?

Higher octane should knock less I would think.

 

[ThatStinging_Jeep]

What does "set up for higher octane fuel" mean?

Higher octane should knock less I would think.

what he means is that the truck wasn't really meant to run high octane fuel, so when you put high octane fuel from the jump the truck is gonna get used to high octane fuel ( your basically spoiling your truck and it only wants premium) and once you put 87 oct. fuel a month later if you will, the truck is gonna start knocking and what not and the truck isnt gonna be happy like in my case,i put premium ever since in my JT and then i was feeling cheap one day and i put in some 87 and the truck was not liking that and it just started knocking like a S.O.A.B and then i put in some octane booster and sorta solved it but ever since that ive been running premium and then im working on just putting 89 and a bit of of 93 and slowly make my way down to 87 so that the truck gets used to it

 

[MrZappo]

Well, I understand what you are saying but I don't really think that it works that way.

These engines have knock sensors and dial back timing to protect themselves. The computer is taking hundreds or thousands of readings per second and adapting the running conditions In favor of a balance of economy and power.

I could see the computer adapting to a fuel type but it should quickly be able to stop any detected knock without "learning" anything.

I'm perfectly content to learn something here but I do not believe that an engine "gets used to" a fuel type.

Am I wrong here?

 

[Jeeperjamie]

Well, I understand what you are saying but I don't really think that it works that way.

These engines have knock sensors and dial back timing to protect themselves. The computer is taking hundreds or thousands of readings per second and adapting the running conditions In favor of a balance of economy and power.

I could see the computer adapting to a fuel type but it should quickly be able to stop any detected knock without "learning" anything.

I'm perfectly content to learn something here but I do not believe that an engine "gets used to" a fuel type.

Am I wrong here?

That's exactly how it works. There a tuning process for engines from the factory into the computer to know how to burn gas a certain way and to the most efficient way. That's why they suggest running a certain octane gas in a vehicle. If you want to run higher octane, buy a tuner and tune the engine to burn the gas right. It's not going to automatically know to burn the higher octane gas the right way and that's why you have a spark knocking. In some cases you may have to buy new spark plugs. The same thing happened to me when I had my JKU and thought burning higher octane gas was better for your engine. I had the same thing happen until I bought a Superchips flashpaqs and tune the computer to know how to burn the gas right. Then I was able to run whatever gas I wanted because it had a 87, 89, and 93 octane tune. Honestly though the 87 tune was the most fuel efficient, running the higher octane tunes on the JKU only gave me a little bit of extra throttle at take off which decreased the gas mileage.

I had the same misconception as you until it was explained in great detail to me by a engineer that knew way more than I did about it. There's a few threads out there on other forums where it's explained in detail as well. Bottom line, it takes regular 87, and if you run something higher you are getting zero benefits and in some cases doing more harm than good.

 

[wannajeep]

A couple months ago I started getting knocks under load (going up hill) at low RPMs. I fed the jeep some 93 octane and that seemed to help, or maybe it was just because I ran out a tank of not so good 87. Next time I got gas I filled it with 89. So far knocks have gone away. This morning I'm near empty and will fill it with 87 and see what happens.

Have you gone through a tank yet and refilled, to rule out the possibility of bad gas?

 

[1JeepFamily]

what he means is that the truck wasn't really meant to run high octane fuel, so when you put high octane fuel from the jump the truck is gonna get used to high octane fuel (your basically spoiling your truck and it only wants premium) and once you put 87 oct. fuel a month later if you will, the truck is gonna start knocking and what not and the truck isnt gonna be happy like in my case,i put premium ever since in my JT and then i was feeling cheap one day and i put in some 87 and the truck was not liking that and it just started knocking like a S.O.A.B and then i put in some octane booster and sorta solved it but ever since that ive been running premium

This makes so much more sense to me. I had/have the exact same experience. I'm now stuck running high-octane. If I go low-octane for a fuel-up, it knocks around like a bat.

 

[kelkolb]

That's exactly how it works. There a tuning process for engines from the factory into the computer to know how to burn gas a certain way and to the most efficient way. That's why they suggest running a certain octane gas in a vehicle. If you want to run higher octane, buy a tuner and tune the engine to burn the gas right. It's not going to automatically know to burn the higher octane gas the right way and that's why you have a spark knocking. In some cases you may have to buy new spark plugs. The same thing happened to me when I had my JKU and thought burning higher octane gas was better for your engine. I had the same thing happen until I bought a Superchips flashpaqs and tune the computer to know how to burn the gas right. Then I was able to run whatever gas I wanted because it had a 87, 89, and 93 octane tune. Honestly though the 87 tune was the most fuel efficient, running the higher octane tunes on the JKU only gave me a little bit of extra throttle at take off which decreased the gas mileage.

I had the same misconception as you until it was explained in great detail to me by a engineer that knew way more than I did about it. There's a few threads out there on other forums where it's explained in detail as well. Bottom line, it takes regular 87, and if you run something higher you are getting zero benefits and in some cases doing more harm than good.

You can run higher octane fuel in a stock vehicle. Any vehicle. All it does is add knock protection and will allow the ECU to add SOME timing (limited by the factory mapping). It will learn to run efficiently this way if you always use that fuel.

If you want to take full advantage of that higher octane fuel, you can tune for it to get the maximum amount of power out of it (from the ability to add more timing). But you in no way have to tune for it.

For example, I used to have a Subaru that was pro tuned for 91 octane (lived in CA at the time) and the tuner recommended adding a few gallons of E85 to the 91 if it was available just for the added knock protection, especially when the weather is warmer. E85 is effectively 105 octane. Now, I wasn't gaining any power from doing this, but if I wanted to, I could have installed a flex-fuel sensor to take advantage of the higher octane.

 

[j.o.y.ride]

I was noticing the smallest of like little weird sound at initial acceleration... nothing like knock I hear from YouTube videos, and I really have no way to describe it. Only at low rpm as it starts to accelerate initially and then gone. Is that what you all are talking about?

 

[Jeeperjamie]

You can run higher octane fuel in a stock vehicle. Any vehicle. All it does is add knock protection and will allow the ECU to add SOME timing (limited by the factory mapping). It will learn to run efficiently this way if you always use that fuel.

If you want to take full advantage of that higher octane fuel, you can tune for it to get the maximum amount of power out of it (from the ability to add more timing). But you in no way have to tune for it.

For example, I used to have a Subaru that was pro tuned for 91 octane (lived in CA at the time) and the tuner recommended adding a few gallons of E85 to the 91 if it was available just for the added knock protection, especially when the weather is warmer. E85 is effectively 105 octane. Now, I wasn't gaining any power from doing this, but if I wanted to, I could have installed a flex-fuel sensor to take advantage of the higher octane.

I'm not sure how accurate it is to say that higher octane adds knock protection because I ran higher octane in my JKU and it began to knock. That's after about 10-12 fill-up in the beginning. I ended up switching back to Regular and after a few cycle and fill ups I was able to make the knocking noise go away. After buying the flashpaq tuner I tried again and didn't have a issue. Worth noting also that I had similar issues in a BMW 328I as well. There a reason they tell you what Type of gas to run. But I will agree that tuning them will get the best bang if you decide to run higher octane fuel. I think there is a huge misconception behind the benefits of running higher octane gas and fully synthetic oil in some cases. If I can find it I'll post the video of the study done in using lower octane in higher octane vehicles and the opposite, it's pretty interesting the results.

 

[kelkolb]

I'm not sure how accurate it is to say that higher octane adds knock protection because I ran higher octane in my JKU and it began to knock. That's after about 10-12 fill-up in the beginning. I ended up switching back to Regular and after a few cycle and fill ups I was able to make the knocking noise go away. After buying the flashpaq tuner I tried again and didn't have a issue. Worth noting also that I had similar issues in a BMW 328I as well. There a reason they tell you what Type of gas to run. But I will agree that tuning them will get the best bang if you decide to run higher octane fuel. I think there is a huge misconception behind the benefits of running higher octane gas and fully synthetic oil in some cases. If I can find it I'll post the video of the study done in using lower octane in higher octane vehicles and the opposite, it's pretty interesting the results.

You must have just had some bad gas. Knock protection is the fundamental reason to go for higher octane. More timing, more likely to have early detonation, which the higher octane protects against. OEM's usually don't tell you what octane to run, they give you a minimum. In the Gladiator manual they just tell you that higher octane doesn't help you.

Another way to talk about it is with air temperature and/or altitude. Early detonation is more likely to happen with warmer air (less oxygen). Higher octane increases the temperature at which early detonation can occur, effectively lowering the chances of it happening at the same air temperature. Higher altitude works the same way as warmer air (less oxygen) which is why in places like Colorado you'll see 85 octane as the minimum octane sold vs 87. The cars can handle the lower octane because they're less likely to knock since their air has a lower oxygen content. All of this is why I typically will run mid grade (typically the 88 octane from Sheetz) fuel when it's really hot out and then I move back to 87 when it cools down.

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