Pinging sound at acceleration

bigchevyz71 · July 5, 2017

So whenever I use lower grade gas for a couple tanks I start to hear a pinging sound under the hood during acceleration. When I go to a high grade or ethanol free it doesn't do it. In the door jamb it has a sticker that indicates it's tuned I'm guessing for better fuel mileage. It was on there when I got it. Thanks for any info about this.

muddkatt · July 5, 2017

Only use the 91-93 octane fuel if it pings on the lower octane fuels. All I run in any of my engines including the lawn mower is 93.

mj0528 · July 5, 2017

I had some with 87 that got worse during the summer. I use 89 now and it's quiet. I also noticed my alcohol % was higher than 10% (13%) so I changed stations and only use Exxon now. Alcohol % is like 6% now. Runs better also. Read somewhere to not take quick trip to get gas and then back home. Get it up to temp and then put a few miles on it after so the computer to have time to recalculate the % correctly. Truck sounds better over all since I changed my gas habits. Also run Techron in it every now and then to clean it up. My 5 year old truck sounds like new now.

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bigchevyz71 · July 10, 2017

Only use the 91-93 octane fuel if it pings on the lower octane fuels. All I run in any of my engines including the lawn mower is 93.

sounds like a good rule of thumb thanks!

I had some with 87 that got worse during the summer. I use 89 now and it's quiet. I also noticed my alcohol % was higher than 10% (13%) so I changed stations and only use Exxon now. Alcohol % is like 6% now. Runs better also. Read somewhere to not take quick trip to get gas and then back home. Get it up to temp and then put a few miles on it after so the computer to have time to recalculate the % correctly. Truck sounds better over all since I changed my gas habits. Also run Techron in it every now and then to clean it up. My 5 year old truck sounds like new now.

Great info I'll need to try that!

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81 K20 · August 12, 2017

Did this fix your problem? How loud did the pinging get??

bgbdwlf2500 · August 14, 2017

What does the sticker say? if its been tuned for anything more than 87 its going to ping. Unfortunately without the tuner the only way to get it back to stock is to have the factory reflash the computer which wont be free (or cheap)

bigchevyz71 · August 16, 2017

What does the sticker say? if its been tuned for anything more than 87 its going to ping. Unfortunately without the tuner the only way to get it back to stock is to have the factory reflash the computer which wont be free (or cheap)

lol I'm scared to get a quote on that one

Did this fix your problem? How loud did the pinging get??

Yes I'm pretty sure putting mid grade in fixed it. I wasn't terribly loud

slimjim2525 · August 17, 2017

Truth is higher octane fuel burns slower. Therefore you will get better MPG, and compared to 87 it will be a wash cost wise.

bgbdwlf2500 · August 17, 2017

Truth is higher octane fuel burns slower. Therefore you will get better MPG, and compared to 87 it will be a wash cost wise.

have to wonder where in the heck you got that info from. my truck gets 17 on the highway on 87 and 12 running e85.

slimjim2525 · August 17, 2017

have to wonder where in the heck you got that info from. my truck gets 17 on the highway on 87 and 12 running e85.

I really think you should educate yourself on E85, and 87, and 93 octane. That's got to be one of the dumbest things I've read in a while.

bgbdwlf2500 · August 17, 2017

I actually have. Gm builds the e85 trucks with a higher flow fuel pump because theres less energy in the 95+ octane e85. I can do math and when I ran e85 hand calculate and truck computer calculated 12 or less. Switched back to 87 when they bumped e85 up. Now getting 17. I dont have to argue with you, theres enough threads on here that will tell you the same thing and not 1 will agree with you.

bgbdwlf2500 · August 17, 2017

http://www.jimellisgreen.com/new-inventory/flexfuel-vehicles.htm#Sierra

http://e85vehicles.com/e85/index.php?/topic/6689-what-does-your-owners-manual-say-about-e85/

Little reading in the second one but that's a factory manual.

slimjim2525 · August 17, 2017

E85 has way less energy per volume, even with the added octane, you will get much less MPG. Comparing 93 to 87 octane, higher octane burns slower, and will give you a mildly better MPG, and when you compare 87 to 93, cost wise, and MPG wise, it will be awash. BTW people are under the wrong assumption that you will get more horsepower using a higher octane fuel. That's wrong. Lower octane fuel is more volatile, burns quicker, and should be used unless there is pre-ignition. Save your premium octane stuff for tuned, or high compression engines.

bgbdwlf2500 · August 18, 2017

E85 has way less energy per volume, even with the added octane, you will get much less MPG. Comparing 93 to 87 octane, higher octane burns slower, and will give you a mildly better MPG, and when you compare 87 to 93, cost wise, and MPG wise, it will be awash. BTW people are under the wrong assumption that you will get more horsepower using a higher octane fuel. That's wrong. Lower octane fuel is more volatile, burns quicker, and should be used unless there is pre-ignition. Save your premium octane stuff for tuned, or high compression engines.

Ive never noticed running 93 that the mileage is better/the same unless I had installed a tune for at least 91 octane. totally agree that if the truck wasn't designed for anything above 87 running it will not serve any purpose. the e 85 actually does produce more power because the e85 trucks have a different tune from the factory for it. the factory actually rated output on 87 and e85. I was running a 91 octane tune in my truck and was paying 1.79 for e85 which gave me the octane requirement but the MPG was down around 12 like I had said.

dkjbama · August 18, 2017

lol I'm scared to get a quote on that one

Yes I'm pretty sure putting mid grade in fixed it. I wasn't terribly loud

As an aside from the E85 debate, which people will never agree on, I would think a dealer could reflash your ECM with a factory calibration using their diagnostic machine. I wouldn't think it would more than an hour of labor. If you want to run 87, get the proper tune in the ECM. Whatever tune you have, it has too much timing advance in it for 87.