Engine Rattle or Ping

[BobF]

What happens when you go from the lower octane to the mid range octane or have you not tried it? I own an 02 and run the mid range with absolutely no problems. What range octane fuel does the owner's manual call for?

I have only used regular unleaded. I will need to try a higher octane to see if it stops. That will certainly change the cost of a fill up!!

 

[Rocket Man]

I have only used regular unleaded. I will need to try a higher octane to see if it stops. That will certainly change the cost of a fill up!!

The cost of gas is nothing compared to the cost of repairing an engine damaged from detonation, if that is what is happening. Hopefully some better fuel cures it. I run a supercharger in my 02 Denali and get 10mpg and it requires Premium or else engine damage will occur. Cost of gas doesn’t enter my mind.

 

[OR VietVet]

Yep, you look at the top of pistons that have been subjected to too low octane or poor quality fuel and detonation/ping occurs and they surface looks like a moon landscape. Typically the next grade up from 87 octane regular is what most places call plus and is 89 octane. It is about $.10 more a gallon. 20 gallon fill is $2.00 more per tank. Way more damage at the piston that will cost a lot more.

I just drove from Eugene, Or. to Medford, Or. on Sunday. About a 330-340 miles round trip and I motored at 75-80 mph the whole way and that is up and down some passes and there was never a missed beat during the trip. That engine performed flawlessly and I got 14.7 MPG. I am very happy with that. Plus, the lady I was with bought lunch at a diner called Black Bear Diner in Grants Pass, Oregon. I was hoping for a pork tenderloin sandwich but no luck but I had the Reuben and it was actually corned beef instead of pastrami and was almost as good as the ones I make. So, good food, good company on a trip and for me, the MPG was great.

 

[fireboat]

Because the 6.2 is designed to run on premium, you will get slightly better mileage if you use it as the engine will not have to retard the timing to prevent detonation from using regular.
The above advice to use top tier fuel is warranted. I had to take my 2008 6.2 with 140k miles apart due to a bad lifter. I was amazed at the amount of carbon buildup in the cylinder heads and intake manifold.

 

[wjburken]

I was hoping for a pork tenderloin sandwich but no luck but I had the Reuben and it was actually corned beef instead of pastrami and was almost as good as the ones I make. So, good food, good company on a trip and for me, the MPG was great.

Sounds like a very enjoyable trip. 14.7 mpg isn't bad for rolling 75-80 over the hills and through the dales. That being said, I have never heard of a Reuben made with pastrami. Everything I've had has always been corned beef except for a local restaurant makes one with turkey.

 

[OR VietVet]

Sounds like a very enjoyable trip. 14.7 mpg isn't bad for rolling 75-80 over the hills and through the dales. That being said, I have never heard of a Reuben made with pastrami. Everything I've had has always been corned beef except for a local restaurant makes one with turkey.

I have seen restaurants cheap the sandwich with pastrami. I always ask.

Remember, I am in Oregon. While there are hills and dales and beautiful scenery there are also some long graded passes that can really drag a rigs momentum down. Those grades have the extra right lane for the trucks to stay in. Lots of stomping on the gas pedal to keep that speed up. That is why I was surprised at the MPG. While I was doing all of this, on the way back, a newer, I believe 2015 or 2016 Tahoe was behind me the whole way and he let me clear the way. He exited about 3 exits before I did when we hit town and he flashed his lights at me. He was using me to clear the way in the left lane.

 

[wjburken]

I have seen restaurants cheap the sandwich with pastrami. I always ask.

Remember, I am in Oregon. While there are hills and dales and beautiful scenery there are also some long graded passes that can really drag a rigs momentum down. Those grades have the extra right lane for the trucks to stay in. Lots of stomping on the gas pedal to keep that speed up. That is why I was surprised at the MPG. While I was doing all of this, on the way back, a newer, I believe 2015 or 2016 Tahoe was behind me the whole way and he let me clear the way. He exited about 3 exits before I did when we hit town and he flashed his lights at me. He was using me to clear the way in the left lane.

Definitely beautiful country out there. Had an aunt and uncle that lived in Roseburg for quite awhile when my cousins were younger. They had a used car lot, a Big A autoparts store and a towing company. Moved to Florida probably 25 years ago. Know what you mean about the long grades.

 

[OR VietVet]

Definitely beautiful country out there. Had an aunt and uncle that lived in Roseburg for quite awhile when my cousins were younger. They had a used car lot, a Big A autoparts store and a towing company. Moved to Florida probably 25 years ago. Know what you mean about the long grades.

Have made the trip to Roseburg several times to go to the VA hospital there. Now we have a new VA hospital here in Eugene for the last 2+ years. If anyone ever comes to Oregon and does not take the time to visit Crater Lake, they miss one of the most spectacular sites I have ever seen. Then a trip to Mt. St. Helen's would be next. Beautiful country out here.

 

[petethepug]

That low octane sound during cold start up is usually carbon build up. Also referred to as piston slap. It’s a known issue on the 6.2L since 07. It should NOT be present after running a tank of 93 octane and an injector cleaner recommended by GM.

It gets more pronounced the colder it gets. Just make sure you CYA and take one of the service employees for a test drive to acknowledge it IN WRITING on the service ticket. If you intend on keeping the truck for more than 5 years do not run 91. The detonation will eventually crack a piston when the motor is under load, like a prolonged grade.

My buddy opted not to trade in his Lexus RX300 with a bad alternator for a new ride because he felt they low balled him. He found out it was a cracked piston during the next oil change. He ran it 24/7 on 91 octane even up into the high Sierras.

That was a sucky bit of bad luck not trading it in a week before. Save 91 octane for off the mountain cruising or keep a couple bottles of octane boost for unexpected high altitude driving.






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[ChrisYukon]

If What you’re hearing Is indeed knocking, you need higher octane.

Edit - do you mean your ‘18 was still brand new?