Engine Pings on 87 Octane... Everyone or just me?

[Loco-diablo]

I ran 89 (mid) since day one.. I switched to 87 (reg) for a few tanks.. mileage dropped, power dropped, I'm back to 89.

[dbrobins27]

Following up on this topic, since I originally chimed in about 8k miles ago(75k on a 2014 5.3) I have been paying closer attention to the pinging noise vs. octane of fuel used.  I definitely hear the pinging noise with the 87 octane and it is noticeable less or even non existent with 89 octane and higher.  During this time I have also towed a 4k lb trailer with and without the higher octane and confirmed that the higher octane reduces the pinging noise.  I have also developed a rough idle.  Last week I took the opportunity to clean the throttle body and remove some build up around the throttle plate and ran a can of the CRC GDI Valve cleaner spray through the PCV port on the drivers side of the intake and after doing that truck is running fine with no pinging on 87.  Lots of folks may discount the effects of octane or carbon buildup or the ability to hear pinging with knock sensors but I am fairly certain of what I hear and can make direct connections to when/what factors contribute to it and I can say as of today the issue is cleared up. Hopefully others that believe they have this issue can also clear it up with a $15 can of cleaner or take it somewhere and do another type of induction cleaning.   

Edited August 8, 2018 by dbrobins27

[KARNUT]

Following up on this topic, since I originally chimed in about 8k miles ago(75k on a 2014 5.3) I have been paying closer attention to the pinging noise vs. octane of fuel used.  I definitely hear the pinging noise with the 87 octane and it is noticeable less or even non existent with 89 octane and higher.  During this time I have also towed a 4k lb trailer with and without the higher octane and confirmed that the higher octane reduces the pinging noise.  I have also developed a rough idle.  Last week I took the opportunity to clean the throttle body and remove some build up around the throttle plate and ran a can of the CRC GDI Valve cleaner spray through the PCV port on the drivers side of the intake and after doing that truck is running fine with no pinging on 87.  Lots of folks may discount the effects of octane or carbon buildup or the ability to hear pinging with knock sensors but I am fairly certain of what I hear and can make direct connections to when/what factors contribute to it and I can say as of today the issue is cleared up. Hopefully others that believe they have this issue can also clear it up with a $15 can of cleaner or take it somewhere and do another type of induction cleaning.   

In 2013-14 when the new 5.3 came out there was tons of data logging. In most 5.3s it was noted that there was lots of KR going on and was recommended the use of mid grade or E -85 if you had the yellow gas cab. The 6.2 was required to use 91-93 grade fuel.


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[MaverickZ71]

1 hour ago, KARNUT said:

In 2013-14 when the new 5.3 came out there was tons of data logging. In most 5.3s it was noted that there was lots of KR going on and was recommended the use of mid grade or E -85 if you had the yellow gas cab. The 6.2 was required to use 91-93 grade fuel.


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The more things change, the more they stay the same.  There were several of these same discussions and this same conclusion on the GMT900 (07-13 1500's) forum back in the day.  

[Matt Bransky]

I have a 2018 Silverado, tune hasn't been touched, and it pings on any brand 87 octane. It drives me nuts. I have aftermarket wheels and had the spedo recalibrated, but it has always done this since new, only 23,000 miles. I'm going to check with the dealership on the next visit, see if there is anything they can do. I would think the knock sensor would see this and richen the mixture a bit to prevent it from happening, but it doesn't. 89 or 91 octane fixes it, but that's not what the manufacturer recommend.

[g2full]

Read somewhere that the direct injection motors don't enjoy the 87. The compression ratio is too high to effectively burn it. But.. you put that in an owners manual and you aren’t going to sell as many trucks

[CamGTP]

Knock sensors are only designed to report the knock and remove timing. It can't change fueling at all.

 

Hearing ping and seeing it ping/knock on a tuner or handheld scanner is another thing. If you have a nice scanner than can do good live data polling without minimal lag you could go for a drive to watch data.

 

Compression ratio isn't really the issue if you ask me, these trucks are running lower compression compared to several passenger cars on the market. My dad has a Mazda with their SkyActive engine it that runs 12.0:1 compression on 87 with direct injection, over 106k miles without any ping/knock issues.

 

The thing that helps these trucks running 87 octane is the direct injection. Spraying fuel directly into the cylinder helps lower the air charge temps. I don't run 87 octane in mine because I've personally tuned my truck to run on anything from 88 E15, 93 octane to true E85 fuels, so lower grade fuel would put me worse off. Even with that said I can still hear something if the engine is loaded right going up a incline in certain gears but when I watch my data logs, nothing is reporting an issue. So I can't say exactly what it is, maybe it's just the sound the engine makes or the noisy injection system coming into the cabin.

[mikedeezxxx]

Run 91 octane or higher only. V8 engines will knock on anything lower. I know the Manual says 87 is fine, but that’s a bunch of BS to sell more trucks.


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[CamGTP]

But I've been running 89 octane for years without knock?

 

I'll save myself the few bucks and not worry about anything.

[papageoff]

I had pinging for years on 87 and I finally broke down and did some testing by running 89 for a few tanks and then 91. The 87 helped, but the 91 eliminated it. A friend also pointed out that the 89 may not be as fresh (in general) as the others since fewer people probably buy that vs the other two.

I don't like paying for it, but it did stop the knock.

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[papageoff]

I had pinging for years on 87 and I finally broke down and did some testing by running 89 for a few tanks and then 91. The 87 helped, but the 91 eliminated it. A friend also pointed out that the 89 may not be as fresh (in general) as the others since fewer people probably buy that vs the other two.

I don't like paying for it, but it did stop the knock.

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Lol, I just realized this was my thread... So I guess you knew what I found. :-D

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[Nitrousbird]

On 12/19/2019 at 8:45 PM, papageoff said:

A friend also pointed out that the 89 may not be as fresh (in general) as the others since fewer people probably buy that vs the other two.
 

Your friend doesn't know what he is talking about.  There is no "89" tank.  There are two tanks at the fuel station, lowest grade offered and highest grade offered.  Everything else is simply a blend of the two to allow for the octane selected.

[papageoff]

Your friend doesn't know what he is talking about.  There is no "89" tank.  There are two tanks at the fuel station, lowest grade offered and highest grade offered.  Everything else is simply a blend of the two to allow for the octane selected.

Neat. Merry Christmas.

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[dclayton]

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[Nitrousbird]

2 hours ago, dclayton said:

 

There sure is a “89” tank at the stations. The blending is done at the rack where the fuel trucks are loaded, only regular and premium tanks there and they are blended as the truck is loaded.

 

 

 

No.

https://auto.howstuffworks.com/gas-pump4.htm