Stunned!! Denali 6.2 spun a rod bearing at 25k..

[Hoedown]

I'm still in disbelief. I was the biggest die hard GM V8 fan in the world until a few days ago. I bought this truck FOR THAT (basically) CORVETTE MOTOR. Do you know how hard it is to see all these trucks around and not like them anymore???? Damn.

They offered Enterprised but our family has plenty of cars.

We think the PO never used premium, bc it was a company car, and it knocked *bad* on regular. Would that have anything to do with it? Still though, 25k? We've put 2,000 miles on it. It just died on the interstate.

Still, so disappointed. Turns out the best truck V8 was the Toyota 5.7 IMHO. My LX570 with 135k you could put a brick to the throttle and let it bounce off the limiter for a whole tank of fuel over and over it's such a beast. It's a gas guzzler and a little behind power wise, but still nevertheless 383 hp is enough and it's just stupid reliable.

I seriously have lost faith in GM, and it's really a shame.

Could bad fuel have caused this??

How do you know it knocked bad on regular unless you filled it?

Knocking is detonation which is brutal on rod and main bearings. Basically, as your crank forces the piston and rod up the cylinder, you regular gas explodes before the piston is all the way up. This puts a ton of stress on the rod and main bearings as you can imagine.

I’m glad you got taken care of!

 

[ALT1345]

So does Toyota. They’re putting engines in the new Tundras. There are videos all over TikTok.

I have been hearing about the Toyota 3.4tt’s turbo and wastegate issues but not thrown rods.

In any case I hate that engine, they should have taken the 5.7 and bumped up the displacement updated it to well over 400 horsepower.

Love my Denali but Toyota’s 5.7 V8 is the best truck engine of the last 20 years. I’d get struck by lightning 10 times in the exact same place at different times before that engine would throw a rod.

Not sure on the warranty situation yet, going to pick it up shortly.

 

[ALT1345]

How do you know it knocked bad on regular unless you filled it?

Knocking is detonation which is brutal on rod and main bearings. Basically, as your crank forces the piston and rod up the cylinder, you regular gas explodes before the piston is all the way up. This puts a ton of stress on the rod and main bearings as you can imagine.

I’m glad you got taken care of!

We picked it up with 24k. You really had to stomp it hard to get it to knock, but it was reallllly loud and noticeable.

I told them to put only a gallon of regular in it. Gonna go get some 93 gas.

 

[Blackcar]

In post #3 OP posted that engine was warranted.

 

[WalleyeMikeIII]

How do you know it knocked bad on regular unless you filled it?

Knocking is detonation which is brutal on rod and main bearings. Basically, as your crank forces the piston and rod up the cylinder, you regular gas explodes before the piston is all the way up. This puts a ton of stress on the rod and main bearings as you can imagine.

I’m glad you got taken care of!

I still wonder about this and the bearings failing. Wonder how many that failed have been running 87? I also wonder about GM changing the “recommended” to 91 instead of 93 between 2021 and 2022…

 

[Marky Dissod]

I also wonder about GM changing the “recommended” to 91 instead of 93 between 2021 and 2022 ...

There's enough price difference between 91 & 93 - where both are available - that this covers GM's arse, and makes them look like they care about driver's expenses.

 

[ALT1345]

I also wonder about GM changing the “recommended” to 91 instead of 93 between 2021 and 2022…

You can't get 93 gas everywhere, like in California.

Got the truck back and she's purring. I'm following break in procedure but I have had a little fun.

It might just be the placebo effect, but I swear this one is a little louder when driving... which is GLORIOUS.

 

[ALT1345]

I thought it was placebo effect but someone else in my family noticed it too...

This new engine is louder, and I couldn't be happier. It rumbles louder.

I don't have to turn down the music to hear the engine anymore, I've noticed.

Man this thing is quick, I think it would beat my R129 SL500.

 

[ChrisYukon]

I thought it was placebo effect but someone else in my family noticed it too...

This new engine is louder, and I couldn't be happier. It rumbles louder.

I don't have to turn down the music to hear the engine anymore, I've noticed.

Man this thing is quick, I think it would beat my R129 SL500.

Mine seems faster, too. Of course, that may be true since the new engine doesn’t have bad bearings. Got back from a long road trip this week, and it feels nice and stable at high speeds.

 

[ALT1345]

Mine seems faster, too. Of course, that may be true since the new engine doesn’t have bad bearings. Got back from a long road trip this week, and it feels nice and stable at high speeds.

Nice, I know I've said it three times but it is louder too in the most glorious way.

Haven't taken her on a road trip yet but am this summer!!!!

What's crazy is there are trucks that are faster, but this V8 feels so good it doesn't matter. This thing is eye-poppingly quick. I love a normally aspirated torque curve.

My friend just rented a Tahoe with the 5.3. He the said base V8 was plenty enough, but it's nowhere near the 6.2.