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Discussion Starter · #1 ·
I took a ride in 85 degree afternoon traffic in my stock Cruze 1.4t AT, with a tank full of premium 93 octane Mobil, the second full fill since the dealer's 87 crap. I experienced horrible knocking and pinging. I stongly suspect that I had crap ass thrash fuel, and never buying anything but Chevron again. I paid $4.20 / gallon for what I thought was going to be high quality premium from a reputable brand, still to be determined if it's the culprit. I also know for a fact that after being stuck in traffic heat soaking for 15 minutes in Miami heat with a crap stock intercooler, IAT had to be a major player also. However, I don't see how a car advertised for 87 octane and readily sold in Miami would knock so horribly especially with 93 octane and part throttle, brand new with 600 miles. So traffic starts clearing up and I am half throttle at a low RPM in 2nd or 3rd gear, where the boost has to be the highest. This was the first time we got moving heat soaking in traffic for 15 minutes with the a/c on, and T/C off (not sure if that gives more boost on those conditions). I heard a horrible violent metallic popcorn sound, clearly detonation. I immediately let off, and my laptop which was recording everything confirmed that in that moment there was over 12 degrees of Knock Retard. I could not believe it. It has to be bad fuel. I am posting a link to a thread where the data log is found, so those of you without EFILive software and / or the ability to view the log can at least see the comments / input on it from other tuners.

LOG - Stock 1.4t Cruze KNOCKING horribly on 93 octane
 

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Mobil/Exxon is pretty shitty fuel IMO. I've never had good experiences with it. I strictly use top tier fuel. I fill up at the same Shell station every time I need to.

If you haven't bypassed your resonator box yet (see the link in my signature), I would highly advise that you do so. This will allow you to pull in cooler air.
 

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Discussion Starter · #3 ·
For those of you without access to "the software" to view the log file, here are some snapshots of the "action", around frame 2722:
Cruze Knock Chart.png

Cruze Knock Data.png
 

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Discussion Starter · #4 ·
FYI, the resonator was bypassed during all this. But the thought did occur to me whether is was helping or hurting. The log file shows a top IAT of 145 degrees...
 

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Discussion Starter · #5 ·
If any of you engineers / scientists / technicians / tuners actually click on the snapshot and zoom in you will find some very interesting info. Looks like 2000 rpm and boosting, over 80% throttle and 140 degree IAT.... classic. I will DEFINITELY repeat logs with the resonator reinstalled, and NEVER use Mobil of its assclown relatives. I also find that just like Vince says the torque calculation is very accurate and this thing has an intercooler sensor.
 

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FYI, the resonator was bypassed during all this. But the thought did occur to me whether is was helping or hurting. The log file shows a top IAT of 145 degrees...
I can almost guarantee that it would have been hotter had you not bypassed it. Trace the duct to see where the inlet is. You'll find that this will pull hotter air from higher up in the engine bay. I still think this was a case of bad gas unless you have some really weird tune.
 

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Discussion Starter · #7 ·
tune was bone STOCK. There is not even support for this model yet (unless it's Vince and his tunes don't knock from what I hear). So it has to be fuel. But I will do back to back logs with the resonator just so we know for sure :)
 

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One more thing, in order to test the difference with and without the bypassed resonator, you need to recreate this scenario. You need to get the car to knock again, then put the duct back in its place, and see if it still does it. If the conditions are different, whether its a change in humidity, load, or heat soak idling time, your results will not be valid.

Since you have the scanning tool, perform a closed test on your own by allowing the car to idle for 5 minutes and recording IAT. Then, put the duct back in and let it idle for 5 more minutes, recording the IAT. Then, remove it again, let it idle for 5 more minutes, and record IAT a third time. If you did this correctly, your first and third reading should be the same, and your second reading with the factory setup should be slightly different, although the difference many be inconsequential. Seems like you wouldn't mind burning off some of that shitty fuel anyway.

I'm tempted to perform this test on my own using the Torque app on my phone, but I'm trying to set a personal fuel economy record with this tank of gas so it would have to wait.
 

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Discussion Starter · #9 ·
I would rather not knock the car again if I can help it. What I am doing is putting the resonator back, then several logs is as similar conditions as I can create. If the IATs never ever reach 145 degrees even as summer gets hotter / traffic worse, I will suspect the mod. If the IATs match or get hotter, we will know the mod helped or did nothing. And if the IATs get hotter and the car never knocks again, we will know it was fuel. (I already think it is for sure). Little less scientific but keeps it simple for me and correct comparison none the less.
 

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I would rather not knock the car again if I can help it. What I am doing is putting the resonator back, then several logs is as similar conditions as I can create. If the IATs never ever reach 145 degrees even as summer gets hotter / traffic worse, I will suspect the mod. If the IATs match or get hotter, we will know the mod helped or did nothing. And if the IATs get hotter and the car never knocks again, we will know it was fuel. (I already think it is for sure). Little less scientific but keeps it simple for me and correct comparison none the less.
Well, did nothing as far as reducing intake temperatures perhaps, but throttle response is certainly improved. Just a note, if its not knocking with the intake back to stock, that doesn't indicate that the intake mod is at fault unless it starts knocking when you bypass the resonator again.

Looking forward to your results.

I'm thinking lawsuit. How does *any* car knock on 93 Octane? A brand new one at that...

Exxon mobile f*cking sucks I hate them and so does my car. Robs me of gas mileage and power every time.
Yeah, they really do. I was given a $25 gas card for exxon mobile and I have no idea what to do with it, lol.
 

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I avoid Exxon or Mobil for gas when I can. My cars don't run right on their gas. I'll have to program my SGII to pick up knock, and see how much it knocks.

Strangely, the Fit loves their 0w-20 motor oil. It's a great match for that engine.
 
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Exxon is top tier, i use it very often along with shell and chevron. they all perform the same. i drive 30K miles a year and tune vehicles as well.

how about posting a picture of a histogram showing a more complete log rather than a picture of an instant moment in time if you really want us to diagnose your problem over the internet (lol).

otherwise, you will have a bunch of armchair automotive experts and shadetree tooners digressing into a complaint fest about how terrible everything in the world is.....not productive.
 

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Well, did nothing as far as reducing intake temperatures perhaps, but throttle response is certainly improved. Just a note, if its not knocking with the intake back to stock, that doesn't indicate that the intake mod is at fault unless it starts knocking when you bypass the resonator again.

Looking forward to your results.



Yeah, they really do. I was given a $25 gas card for exxon mobile and I have no idea what to do with it, lol.
I'll take that free gas card ;)!!!
 

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Exxon is top tier, i use it very often along with shell and chevron. they all perform the same. i drive 30K miles a year and tune vehicles as well.

how about posting a picture of a histogram showing a more complete log rather than a picture of an instant moment in time if you really want us to diagnose your problem over the internet (lol).

otherwise, you will have a bunch of armchair automotive experts and shadetree tooners digressing into a complaint fest about how terrible everything in the world is.....not productive.
I guess it really depends on the specific gas station. I've had some very bad tanks of gas with various stations. The only Mobil station I have nearby caused my Bonneville GXP to run rougher than the Shell and Phillips 66 stations I have closer to me. I stopped going there.

Sent from my HTC Vision using AutoGuide.com App
 

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Discussion Starter · #17 · (Edited)
Well, did nothing as far as reducing intake temperatures perhaps, but throttle response is certainly improved.
If you haven't bypassed your resonator box yet (see the link in my signature), I would highly advise that you do so. This will allow you to pull in cooler air.
I can almost guarantee that it would have been hotter had you not bypassed it. Trace the duct to see where the inlet is. You'll find that this will pull hotter air from higher up in the engine bay.
lol

With all due respect, do you really think that engineers sacrificed IAT which affects reliability, efficiency and power for... a little noise? Perhaps it would be better if we research before advising that everyone perform a miracle mod. Your claim of better response is indeed accurate and proven.

0320122112a_296817 (1).jpeg

This is from Greg Banish tuning book I am reading so I can learn about this.
 

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Discussion Starter · #18 ·
Exxon is top tier, i use it very often along with shell and chevron. they all perform the same. i drive 30K miles a year and tune vehicles as well.

how about posting a picture of a histogram showing a more complete log rather than a picture of an instant moment in time if you really want us to diagnose your problem over the internet (lol).

otherwise, you will have a bunch of armchair automotive experts and shadetree tooners digressing into a complaint fest about how terrible everything in the world is.....not productive.
In my first posted I linked to a complete datalog file. (forum doesn't allow it here). Since you tune vehicles, maybe you can view it or download a free demo version of EFILive, the ONLY publicly available tuning software with full support for the Cruze right now. Not sure how to or why create a pictogram, I posted a complete standard file in the tuning forum so knowledgeable folks can comment and a link for us to view. (Also in my first post). I don't need you to diagnose it thanks although you input is welcome and respected.

There are MANY variables, but these cars are extra sensitive to fuel so I will stick with Chevron. If top tier Exxon is performing well for you and all runs the same, cool beans. I aint knocking you...
 

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I agree with you BOOST, i'd say the gas......which kinda sucks (n)

Just take notes and see if any other weird episodes happen to your Cruze.

GoodLuck Bro, Delta Out
 

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lol

With all due respect, do you really think that engineers sacrificed IAT which affects reliability, efficiency and power for... a little noise? Perhaps it would be better if we research before advising that everyone perform a miracle mod. Your claim of better response is indeed accurate and proven.

View attachment 4285

This is from Greg Banish tuning book I am reading so I can learn about this.
Yeah, I really think that's why they did it, and if you disagree, go ahead and show me exactly where the air is pulled from in the factory intake once it goes through the resonator and the 3 feet of plumbing. I'll give you a hint: its right behind the sealed upper grill.

I know you're aware that timing can be pulled at pre-set amounts based on IAT, and I wouldn't be surprised if that's exactly what they did, thinking the air to air intercooler would make the difference minimal enough.

Its not a miracle mod, its a free way to improve throttle response and improve a slight bit of performance while not pulling hot air from nearly the hottest area of the engine bay.

What you're reading is what I've tuned a dozen times. The moment you change the size of the MAF tube or any tube near it, you need to re-calibrate the MAF table. However, think about where the air has to go before it gets to the MAF. From the MAF onward, you have a diffuser at the end of the pipe, similar to a MAF screen on older GM cars. You then have an air filter which basically filters any turbulence coming through the pipe as if the diffuser didn't do a good enough job, then you have a specific sized intake duct at the bottom of the airbox. All this remains unchanged. The only thing you're changing is intake temperatures pre-turbo and removing 3 feet of restrictive tubing and a resonator box.

Maybe they also did it to make air filters last longer thinking if you pulled air from lower down in the engine bay, you'd also pull more dirt. Time will answer that one.

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