Pinging at WOT...

[iamdub]

first off I appreciate what you wrote...you asked where I got my information from and it is written right in the owners manual...

your latest response you mention your response was based on GM's Service Information...that's the first I had read this...I believe GM's service information would be more current than an 18 year old owners manual...

I asked here because I don't know if this is "normal" or not and I believed it not to be normal and that prompted my asking on this Forum...

...I read here on this Forum, advice that I should go with higher octane...that higher octane won't make a difference...that what I am experiencing is normal...that it is not normal...at what point do I decide whom to believe???...prior to your last response the only thing from GM I had was from the owners manual...now you've added the GM Service Information...I did not have that information prior

I appreciate everyone's responses and I have to gauge what I do by those responses gathered here and elsewhere...when someone has more information I assume gleaned from years of working on or experience I weigh that more heavily than I do some anecdotal responses...

thank you for your responses...

Bill

"In the manual", "not in the manual"... IMO, the manual is not a Holy Bible. GM has proven in a few instances that their recommendatinos/allowances aren't always ideal. There are factors influencing their specifications that common mechanical sense would disagree with. For example, GM has to make sacrifices to meet EPA regulations. These sacrifices usually only result in added complexities and maybe a few lost HP. Remember the EGR systems from back in the day? These measures to satisfy EPA regs caused reduced power and carbon issues in the intake and combustion chambers and even reduced engine life. Do YOU, as the vehicle owner HAVE to keep such things if you can circumvent them and improve the operation and lifespan of your engine? Yes, this is what inspections are for. But, where there's a will, there's a way.

Also, are you sure of the quality and true octane rating of the fuel in your tank? It might be borderline 87 at best when it's fresh, as required by law. But, stuff happens. For a few extra bucks per tank, you add a little wiggle room should the fuel not be as advertised. Also, for those few extra bucks, you're cushioning yourself from a potential engine rebuild or replacement.

Just because GM will allow something, to whatever extent and for whatever reason, doesn't supersede physics.

 

[adventurenali92]

Personally, I don't like ANY pinging under load. Pinging is still spark knock/pre-detonation, just in mild form. But, still harmful, IMO. I believe there are some things that GM considers "normal" that should be questioned. Their allowance for oil consumption is ridiculous.

I'd run 89 or higher of Top Tier fuels. My bet is 89 would reduce the severity and 91-93 would eliminate it. I suspect that it's only a recent occurrence due to the warmer weather. Maybe the ambient temps weren't so high a month ago? Your 2000 Escalade had a Gen 2- a totally different engine with lower compression and a milder tune to avoid spark knock (pinging) altogether. The '02 Avalanche had a Gen 3 LS engine very similar to your current Denali engine which is a much stronger design over the Gen 2. Instead of being tuned to always stay safely below the pinging threshold, it's tuned to "ride the line" and dial it back a little when it detects pinging. Running higher octane fuel allows it to stay riding that line and giving you its best.

If your Denali is a FlexFuel vehicle and you're okay with buying high octane gas, you can run E85 and come out ahead financially and performance-wise.

Just for clarity based on @iamdub ’s last sentence in this reply…. The LQ4 6.0 is not a flexfuel capable engine so I would not recommend putting E85 in the OP’s tank. Lol.

 

[Mudsport96]

Possible that there may be excessive carbon build up in the engine as well. Causing the problem.

 

[Trey Hardy]

...and somehow I missed that...thanks SO much for the help...I may try 93 octane at next fill up but honestly I've only heard the pinging 3 times in my ownership 1 month/650 miles and only when mashing the gas pedal from about 45/50 MPH getting on the expressway/highway...

Thanks again!

Bill

Mine would do it all the time when I first got it. I’m cheap I run 87 I do add a lil marvel mystery oil to the gas or some bezo B12 on each fill up to prevent the spark knot or pinging I’ve had good luck for a couple years now doing this! I diddnt do it this one time coming home and guess what? She was pinging at wide open throttle

 

[iamdub]

Just for clarity based on @iamdub ’s last sentence in this reply…. The LQ4 6.0 is not a flexfuel capable engine so I would not recommend putting E85 in the OP’s tank. Lol.

Thanks for the clarification. I thought Flex Fuel capability was an option for the Denali/similar rigs.

 

[adventurenali92]

Thanks for the clarification. I thought Flex Fuel capability was an option for the Denali/similar rigs.

As far as I’m aware, the engines in the GMT800 platform that are flexfuel capable were some of the non Denali 5.3 Yukons and 5.3 powered hoe/burbs. Not sure why the 6.0 isn’t but I’m not fully read up on it. So I could be wrong. My owners manual doesn’t not mention anything about flexfuel capability in the fueling section.

 

[rockola1971]

As far as I’m aware, the engines in the GMT800 platform that are flexfuel capable were some of the non Denali 5.3 Yukons and 5.3 powered hoe/burbs. Not sure why the 6.0 isn’t but I’m not fully read up on it. So I could be wrong. My owners manual doesn’t not mention anything about flexfuel capability in the fueling section.

If it was flexfuel it would have a flexfuel tag on the rear of the Denali. My 05 Denali is not a Flexfuel. Both of my 03 Vin Z Tahoe LT's are Flexfuel.

 

[adventurenali92]

If it was flexfuel it would have a flexfuel tag on the rear of the Denali. My 05 Denali is not a Flexfuel. Both of my 03 Vin Z Tahoe LT's are Flexfuel.

Yeah I knew about the rear tag. Wonder why they didn’t make the LQ4 6.0s flexfuel capable. Not that it would make a difference for me since literally none of the stations up here in the mountains where I live even carry E85 to run my truck anyways lol

 

[rockola1971]

Yeah I knew about the rear tag. Wonder why they didn’t make the LQ4 6.0s flexfuel capable.

Likely they wanted to be able to boast in advertisement the HP rating of the LQ4 and it would have been substantially lower with E85. Also there a quite a bit of differences in the E85 able fuel system vs. the standard one. An E85 engine requires more fuel to get the same amount of power compared to 87 octane because ethanol does NOT have equal to or higher BTU output that regular unleaded 87 octane has. This is why you can drive further on a gallon of 87 octane than you can with a gallon of E85. So the flow rate has to be higher for the injectors. Certain seals and the pump have to be rated for ethanol which is corrosive.

Now keep in mind that arguement of E85 having less power output than 87 Octane is based on a stock vehicle. A engine can be tuned for E85 and get substantial HP gains BUT no matter how you slice it you will always need more E85 to get the same equivalent that you could have gotten out of 87 octane. High compression engines love ethanol because you can get more ignition timing out of it, the cylinders run cooler on it and ethanol has a substantially higher octane rating. E85 octane rating is 100-105!

 

[SilverSport]

I thought E85 had more HP (advanced timing?) but less MPG...that was the experience my brother had with his flex fuel Silverado and I had with a flex fuel F150...I recall them even being advertised with more horsepower when using E85...anyway, they seemed more peppy to me but lost 2-4 MPGs

Bill