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

[papageoff]

So, I've had this truck about 15 months.  I bought it used from Carmax  and ran 87 octane for the first year or so.  I noticed that I got a good bit of engine pinging.  It's would get worse under load or in hot weather.  And during that year I always felt like the truck was a bit of a dog.  

 

In January, I'd had enough and bumped up to 91 octane for a couple months.  It got much better but didn't quite go away.  About 3 or 4 tanks ago, I switched to 93 octane (premium, in my area) and I don't think I've heard it ping once.  The mileage hasn't changed (unsurprisingly), but the truck just feels "peppy."  The throttle response is massively improved and it's a much better driving vehicle.  I think the best way I can describe it is that it's no longer lazy.  I mean, it's not a sports car, but it no longer needs a few seconds to get it to accelerate.  I know the instant response to that is "it's all in your head" but my wife who has no idea (read: doesn't care) what's been going on commented the other day that I haven't complained about the truck's performance lately.  I'm not excited about having to feed this beast premium, but if I don't I'm afraid it's going to tear itself up.

 

Also, I haven't changed gas stations through this time and the ones I use are busy, top-tier locations so I'm not thinking the quality of the gas is involved.  

 

I'm thinking the truck was tuned by the previous owner.  I'm going to ask about that at my next service visit, but I don't expect they'll tell me anything.  Is there a way I can verify if the truck is on the stock tune?  Also, has anyone else had a similar experience? 

[calgator73]

So, I've had this truck about 15 months.  I bought it used from Carmax  and ran 87 octane for the first year or so.  I noticed that I got a good bit of engine pinging.  It's would get worse under load or in hot weather.  And during that year I always felt like the truck was a bit of a dog.  
 
In January, I'd had enough and bumped up to 91 octane for a couple months.  It got much better but didn't quite go away.  About 3 or 4 tanks ago, I switched to 93 octane (premium, in my area) and I don't think I've heard it ping once.  The mileage hasn't changed (unsurprisingly), but the truck just feels "peppy."  The throttle response is massively improved and it's a much better driving vehicle.  I think the best way I can describe it is that it's no longer lazy.  I mean, it's not a sports car, but it no longer needs a few seconds to get it to accelerate.  I know the instant response to that is "it's all in your head" but my wife who has no idea (read: doesn't care) what's been going on commented the other day that I haven't complained about the truck's performance lately.  I'm not excited about having to feed this beast premium, but if I don't I'm afraid it's going to tear itself up.
 
Also, I haven't changed gas stations through this time and the ones I use are busy, top-tier locations so I'm not thinking the quality of the gas is involved.  
 
I'm thinking the truck was tuned by the previous owner.  I'm going to ask about that at my next service visit, but I don't expect they'll tell me anything.  Is there a way I can verify if the truck is on the stock tune?  Also, has anyone else had a similar experience? 

There is a way but if the dealer finds out and you have any kind of warranty left it will likely be voided.

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[calgator73]

It might actually be better for you to put some Techron in the tank and be sure you use top tier 87 octane fuel for a few tanks and see if your problem goes away. Some of your symptoms sound like bad gas. There is a video from Lingenfelter I believe showing how the 5.3 L reacts to 87 and 89 and I believe 91 octane fuel. the engine really does like 89 octane fuel. If you have access to "E85" and your truck is compatible, look for the yellow fuel cap, then you will see a massive Improvement in throttle response and horsepower.

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[papageoff]

It might actually be better for you to put some Techron in the tank and be sure you use top tier 87 octane fuel for a few tanks and see if your problem goes away. Some of your symptoms sound like bad gas. There is a video from Lingenfelter I believe showing how the 5.3 L reacts to 87 and 89 and I believe 91 octane fuel. the engine really does like 89 octane fuel. If you have access to "E85" and your truck is compatible, look for the yellow fuel cap, then you will see a massive Improvement in throttle response and horsepower.

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I'll try that for a few. I go through a tank every week or 10 days so premium is burdensome.

I don't have the ffv badge so I don't think it can run e85. I'll look into it more deeply though.

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[papageoff]

52 minutes ago, calgator73 said:

There is a way but if the dealer finds out and you have any kind of warranty left it will likely be voided.

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Yeah, I wondered about that. The other side of it is if the premium is masking another issue that would otherwise be fixable, it'd be nice to run the less expensive fuel.

That said it runs so much better on premium, I have to believe that it has been tuned for 91 and the engine was just doing what it could pulling timing, etc. to make 87 work.

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[pmhinatl]

Yeah, I wondered about that. The other side of it is if the premium is making another issue that would otherwise be fixable, it'd be nice to run the less expensive fuel.

That said it runs so much better on premium, I have to believe that it has been tuned for 91 and the engine was just doing what it could pulling timing, etc. to make 87 work.

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My ‘15 Sierra 5.3 CCSB (I’m the 3rd owner) pings and feels tired on 87 regular, but I definitely believe it improves with mid-grade. I don’t feel much of a difference with premium tho. I’ve wondered the same thing about a tune, but would be surprised if there was one installed. The previous owner didn’t seem the type nor did he mention anything to me. It’s a mystery. So maybe the next question should be: is there an easy way to check the bcm for a tune -without - going to the dealer?

M.

[calgator73]

If it's a well done tune...no. everything will look the same except the flash counter. GM has a process to compare the actual program installed to factory spec.

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[calgator73]

I'll try that for a few. I go through a tank every week or 10 days so premium is burdensome.

I don't have the ffv badge so I don't think it can run e85. I'll look into it more deeply though.

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You'll have a yellow fuel cap and an alcohol sensor installed on your fuel line forward of the fuel tank. No flex fuel badging

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[papageoff]

1 minute ago, calgator73 said:

You'll have a yellow fuel cap and an alcohol sensor installed on your fuel line forward of the fuel tank. No flex fuel badging

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My fuel cap is black.  I figured it wasn't compatible with e85. 

Geoff 

[dbrobins27]

I have noticed the same thing.  A good bit of pinging on 87 and when I run 89 it clears it up and is much more responsive.  I have tried 93 and didn't feel as much difference as 87 vs 89.  I have about 67k on a 2014 5.3

[calgator73]

I think all 2014s have flex fuel.. Try that

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[Loco-diablo]

Good timing for this post. I bought my 2017 5.3 new 10 months ago and have used midgrade 89 since day one. Today for the first time, I actually filled with 87.

40 miles in to the tank full and I'm not noticing any difference. With gas going up ($2.59 shell 87. $2.89 shell 89), I thought I try reg unleaded.  

[wforrest08]

5 hours ago, papageoff said:

 Is there a way I can verify if the truck is on the stock tune?  Also, has anyone else had a similar experience? 

First thing I would check if you haven’t already does the truck cycle in and out of V4? I would think most (not all) guys going with a 91 octane would also tune out AFM. Factory wheel/tire size or oversized? If oversized use a mobile GPS and see if the speed matches the speedo (within 1-2mph) if it does odds are somebody has at least done a recalibration and possibly a tune. There’s tire revolution charts on line for comparisons.

 

 

If you want to run 87 octane Blackbear (probably others as well) will do a 87 tune. My 15 was tuned by them they sent me a 87 and a 91 tune. Can’t comment on the 87 tune as I’ve only ever ran the 91 tune. You would have to do the math to see if it would be worth your investment cost per tank difference and how long your planning on keeping the truck. If you sell/trade the truck down the road you program the truck back to stock and it “unlocks” the tuner so you can use it on your next one or sell it to recoup some of your investment. If your investment is $600 and your saving $7.50 per fill it’s 80 tanks to recoup if you fill up 26 times a year recovery time is 3 years. 

[papageoff]

18 hours ago, wforrest08 said:

First thing I would check if you haven’t already does the truck cycle in and out of V4? I would think most (not all) guys going with a 91 octane would also tune out AFM. Factory wheel/tire size or oversized? If oversized use a mobile GPS and see if the speed matches the speedo (within 1-2mph) if it does odds are somebody has at least done a recalibration and possibly a tune. There’s tire revolution charts on line for comparisons.

 

 

If you want to run 87 octane Blackbear (probably others as well) will do a 87 tune. My 15 was tuned by them they sent me a 87 and a 91 tune. Can’t comment on the 87 tune as I’ve only ever ran the 91 tune. You would have to do the math to see if it would be worth your investment cost per tank difference and how long your planning on keeping the truck. If you sell/trade the truck down the road you program the truck back to stock and it “unlocks” the tuner so you can use it on your next one or sell it to recoup some of your investment. If your investment is $600 and your saving $7.50 per fill it’s 80 tanks to recoup if you fill up 26 times a year recovery time is 3 years. 

So, you got me to thinking...

 

• It does use v4 mode (Aside: but not nearly as often as I'd have thought.  I'd be really interested from an engineering standpoint to understand the algorithm they use to decide when to trigger it, honestly.)
• It's on the factory wheels/tires.  It's possible that the previous owner removed/replaced them, but given how worn the tires are, I'd doubt it.
• The speedo is consistently within 1mph of the GPS as measured by Torque Pro and my OBDII connector.  

So, yeah... All that adds up to no tune, most likely.  Unfortunately, that leads me back to the question of why it pings so much on 87 octane if that's what it's supposed to run per the manual.  I asked my neighbor about his '17 and he said he's always run 93 and never noticed pinging.  He did the same in his '15, too.  I guess he just doesn't like money, I dunno.  

[hirdlej]

I don't know how much more premium is in your area vs 87 but in MN it's only 20 cents more a gallon.  20 cents times 20 gallons (at fillup) equates to 4 dollars.  I would just spend the $4 at each fillup and be done.  I run 91 non-oxy in all my stuff since I don't like ethanol touching the fuel components of my vehicles.