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

[Grumpy Bear]

How does one 'hear' or 'sense' ping on a knock sensor equipped motor with computerized sensor generated ignition retard?

 

Using a scan gauge I can measure some knock retard but I've never heard it. Why? Ignition gets retarded to the threshold. Just curious.

 

If you can I'd be checking the sensor. 

Edited April 25, 2018 by Grumpy Bear
additional content

[papageoff]

On 4/25/2018 at 10:40 AM, Grumpy Bear said:

How does one 'hear' or 'sense' ping on a knock sensor equipped motor with computerized sensor generated ignition retard?

 

Using a scan gauge I can measure some knock retard but I've never heard it. Why? Ignition gets retarded to the threshold. Just curious.

 

If you can I'd be checking the sensor. 

Best way I can describe it, is that it sounds like a small marble or pebble is rattling around.  It will usually happen under load and more often/severe when it's hot.  

 

As for the knock retard, systems like that are not perfect in my experience and do have limits.  I've also got a miata with knock retard and have noticed it do it from time to time, but never as severe as this.  I'm going to go back to 87 for a tank or two just to see if the issue returns and if so I'll start pursuing it with the service dept..  You make a good point, that I should monitor the sensors.  Maybe they're not working properly.  I'll see what I can set up in Torque Pro for data logging when I switch back.

 

 

[Grumpy Bear]

On ‎4‎/‎27‎/‎2018 at 4:55 AM, papageoff said:

Best way I can describe it, is that it sounds like a small marble or pebble is rattling around.  It will usually happen under load and more often/severe when it's hot.  

Run a colder thermostat???? 

[Jon Neighbors]

My brother and I were just talking about this last weekend. He has a 2016 with the 5.3 and I have the 2018 with the 6.2

We both notice pinging when running on 87 octane and yet when we trailer tow we both fill up on 91 or 93. When we do both of us have been paying attention tot he trailers and not the pings so I'll have to make it a point next trip to listen.

On a side note I never had the pinging with my 2002 6.0 liter in the Yukon XL.

[papageoff]

12 hours ago, Grumpy Bear said:

Run a colder thermostat???? 

That's an option...  I would love to hear my dealer's "reasons" for why it will void my engine warranty.  

[papageoff]

46 minutes ago, Jon Neighbors said:

My brother and I were just talking about this last weekend. He has a 2016 with the 5.3 and I have the 2018 with the 6.2

We both notice pinging when running on 87 octane and yet when we trailer tow we both fill up on 91 or 93. When we do both of us have been paying attention tot he trailers and not the pings so I'll have to make it a point next trip to listen.

On a side note I never had the pinging with my 2002 6.0 liter in the Yukon XL.

Interesting, I'm glad I'm not alone, I guess. 

 

I switched back to 87 this tank, but I still had a ¼-tank of premium when I filled.  I haven't noticed it pinging yet, but it's mixed and I haven't driven much.  So, after another tank I should know more.

[Grumpy Bear]

3 minutes ago, papageoff said:

That's an option...  I would love to hear my dealer's "reasons" for why it will void my engine warranty.  

Because it will make it last longer than he wants it to? Jet Performance makes a 170 and a 180 F. They have a 207 F in them. No one currently makes a 192 F; the standard forever, that will fit the factory housing. There is also the option of an upper radiator hose thermostat housing (billet) install that lets you use the SBC thermostats for which there are allot of choices. 

 

These Ecotec3 motors all have under piston crown oil spray cooling and an oil cooler in the radiator tank. So cooler water = cooler oil, cooler piston crown, higher resistance to knock. That's the theory anyway. 

 

That said you still need to look into the sensor and have them have a look see at the flash (program). 

[papageoff]

12 minutes ago, Grumpy Bear said:

Because it will make it last longer than he wants it to? Jet Performance makes a 170 and a 180 F. They have a 207 F in them. No one currently makes a 192 F; the standard forever, that will fit the factory housing. There is also the option of an upper radiator hose thermostat housing (billet) install that lets you use the SBC thermostats for which there are allot of choices. 

 

These Ecotec3 motors all have under piston crown oil spray cooling and an oil cooler in the radiator tank. So cooler water = cooler oil, cooler piston crown, higher resistance to knock. That's the theory anyway. 

 

That said you still need to look into the sensor and have them have a look see at the flash (program). 

Wow, I didn't realize there were squirters for the pistons.  That's a pretty robust design.  Maybe I should get a turbo... That'll fix the issues.  

[Loco-diablo]

For the first 10 months of owning my truck i used mid grade (89) exclusively. Just recently (two tanks ago), I changed to reg (87).

I haven't noticed any difference in performance OR mpg. I'm gonna stick with 87 for the time being.

[tnchevy]

My truck runs just find on 87 octane and so do all the other 5.3 equipped trucks.  Those that think it runs better on higher octane are just telling themselves that.  Get good quality gas and your truck will run just fine.

[Donstar]

I switched to 89 a couple of years ago.  Prices have reached above $1.60 per liter (+$6.25 US gallon) in my region so I tried going back to 87.  After a couple of tanks of 87 I noticed an occasional sound like op describes.  I suspect I may have picked up a tank of bad gas but I returned to 89 in case that was the issue.  The sound has not returned even when pulling my travel trailer up steep hills.  The octane issue is debated ad nauseam elsewhere in this forum.  Our trucks are designed to run on fuel with a minimum octane rating of 87.  Nothing wrong with exceeding the minimum, imo.

[diyer2]

My 2 cents.

My 2012, 5.3L 6 speed has had 85, 87 and 91 octane. This is what is available in Colorado.

It is stock except for a K&N air filter.

I have towed with all three octanes and have never had a ping issue.

The heaviest load was 5-6 K pounds I think.

 

This seems to be related to direct injection engines, correct?

 

[calgator73]

This website has lots of good info on the l83

http://www.lingenfelter.com/forum_lingenfelter/forum/lingenfelter-forum/general-motors-suv-trucks/1245-2014-1500-silverado-with-5-3l-l83-engine-work-begins

There was Lingenfelter article with Dyno testing of 87, 89, 93 and e85. Can't find it now but it seemed to imply 89 and e85 were best.

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[Mike GMC]

It could be a carbon build up issue in the combustion chamber that effectively increases the compression ratio.  Get a can of BG44K and run it in a full tank.  I would use 93 until the issue is corrected if I were you.  Step down slowly to mid grade then regular to see if it reoccurs.  If it does, stay with the higher octane.  Knocking and pinging will eventually do significant engine damage.

[papageoff]

Time for an update...

I switched back to regular 87 a few tanks ago and it's only pinged once or twice. It's enough that I'll probably stay on 89 for my base fills and when summer comes move up to 93.

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