whistleblower

I thought vapor lock was a thing of the past but ... but it sure felt like something similar. Your point is well taken - feels like this is going to be an annoying issue until something ultimately dies. The dealer wanted me to put it on a tow truck immediately yesterday. Of course, it would have arrived at the dealership, they would have looked this morning and it would have started with no issues... Could this be a fuel pump going bad? I surely cannot be the only 6.2 out there that has experienced this. Is there anything in the fuel system, from tank to cylinder, that could potentially be loose? Full tank of costco premium gas, based in Georgia.

She just fired right up! What in the world. The motor just started and idled without batting an eye. No codes (though, I don't have a super sophisticated ODB2). Kids in bed, I just walked outside to check for codes, ~7pm where I am now. As mentioned, the motor started right up. ~65 degrees F outside. It was ~1:30pm when the motor was last running, maybe 75 degrees F. 1:45pm when I first experienced the start / rough idle / die. As referenced earlier, felt like the motor was starving for fuel. I tried restarting the engine a dozen times this afternoon with the last failed attempt at ~4:30pm. Is vapor lock a thing with these engines? Is there a filter somewhere that might be blocked?

Believe the battery is original, ~2 years old. Earlier I disconnected and reconnected thinking maybe it would reset something, no luck. Don't have my tool to check voltage with me, will do this evening.

Model year 2020, manufactured in late 2019, 6.2L with ~70k miles, ~1,900 hours. Engine suddenly won't run. It fires up, idles rough for one-two seconds, then dies. Runs no longer than 2-3 seconds. This has all transpired in the last hour. I returned home from a short errand, shut engine off and went inside, walked back outside to start the vehicle but have not been able to get it to run ever since. Engine was shut off for ~10 minutes between running normally and suddenly dead. No lights on dash, no 'check engine' Any ideas? Perplexed. Feels fuel related (pump? pressure?) or maybe a sensor is erroneously shutting down the motor. These are just guesses, I'm somewhat at a loss given the motor gave no warning of issue and has been running pretty much flawlessly. Any tips or hints are appreciated.

Thanks everyone for the thoughts. Pardon delay on my end, I was on vacation last week where I rented a 2021 Silverado 1500 with the 5.3L and put about 800 miles of highway / backroads driving. The 2021 Silverado had ~40k miles on it and ~1400 hours. A couple thoughts related to responses to my original post as well as the comparison between the 2021 Silverado and my 2020 Yukon XL: Hm. When I think "rumble strip effect", I think very noticeable vibration, which I don't have. Mine is more a subtle surging, like the vehicle wants to go! but I only have a small amount of gas pedal applied. Feels like a pulse, almost as if I was pulsing the gas pedal but I'm not. On the idle, its not very much. 50-100 rpm shudder / stumble. Def feels a little lean. I have only used 93 octane. That said, I just filled up for the 4th time so not a ton of miles with 93 octane. As others have said, I think its safe to assume that the cheap 87 was run through the vehicle prior to my ownership. Regarding my experience with the 2021 Silverado w/ 40k miles - this truck seemed much "smoother", generally, than my 2020 6.2L. While it didn't have the same power, the acceleration, the idle, everything about it is what I'd expect in a new-ish vehicle. I'm not sure what transmission this truck had, maybe the 10 speed? Regardless, the acceleration, low rpm cruise, idle was all superior to my truck. I'm going to keep my date with the dealer (lord save me) and try and find a 6.2L on their lot to drive around while I'm there for comparison purposes. I'll report back with what the dealer finds. I have no doubt that SOMETHING will be found that I will need to pay for... Thanks all for the thoughts.

Recently purchased a 2020 Yukon XL with 60k miles with the 6.2L. Fleet car and was told maintenance was is up-to-date but who the heck knows. My questions after ~1,000k miles of driving split between city and highway: 1 - I feel light surging at various RPMs and various speeds. Its hard to recreate but I'll be driving, will forget about it and then will feel it again. Typically happens on acceleration but I noticed it the other day at ~70-75. Any ideas? Seems to happen mostly at low rpms but I have not been able to define the pattern. 2 - Rough idle. I'll be sitting at a stop light, not thinking about it, and will suddenly feel a shake, almost like a miss. Same characteristics when starting cold and when warm. Almost more apparent when warm. 3 - Less of a concern but just want to confirm that this is normal. After the engine is warm, my oil pressure drops to ~18-20 when at a stop light, then jumps up to ~40 when underway. Oil is full. Confirm this is normal? Regarding 1 and 2, I'd love input from people who know these motors. I've done a bunch of reading and have an appointment with a dealership to see if they can find anything [which, honestly, I'd love to cancel - terrified of the potential bill]. I hate to self diagnose as I'm not a mechanic but have found posts referencing new plugs/wires as a fix as well as removing carbon from the intakes. Any ideas? If its as simple as new plugs/wires, I'm going to cancel the dealership visit and find a local mechanic to do that. For those with higher miles on your 6.2, how often are you cleaning the carbon? The power of this engine is awesome but honestly I've been a little disappointed with the overall driving experience. My previous car to this, 20+ year daily driver, a 2000 F150 with the "terrible" 5.4 triton @ 200k miles, is much smoother than my shiny new(ish) Yukon.... which makes me think its something that can hopefully be corrected! Thanks in advance

Thanks. Do you know where the sensors are located? Wondering if mine have been impacted somehow.

Glad I found this thread. Just bought a new-to-me 2020 Yukon XL with 62k miles on the 6.2L. Previous owner was not mechanically fluent in the slightest and I have no maintenance records outside of verbal "I took it in for an oil change" statements. Noticed immediately that I have a "rough" idle. I use "rough" loosely - not a cough/spit/shake about to die rough but a +/- 50-100 rpm change, enough for an observant operator to notice. Slight shake when idling. I've seen a couple threads arguing that this is normal on a 6.2L and to just live with it. I'm wondering if a plug/wire/coil swap would help...? Re: keeping the intake and top end clean - any chance someone has a video on this procedure [quoted below]?

Truck is a 2020 Yukon XL Denali. This is a used but new-to-me truck. I confirmed in the settings that the handsfree is selected "on" As title says, my handsfree liftgate is not working and I'm looking for guidance as to where to start troubleshooting the issue. I crawled under the bumper this morning but could not visually identify a sensor. Where should I start looking to chase down the issue? It should be noted that when I picked up the truck, it was missing the tow-hitch cover and the very bottom of the bumper, directly below the hitch where the bottom of the hitch cover normally attaches, was broken. Previous owner had backed into something. Wondering if this might affect the hands-free operation. Any guidance is appreciated - thanks!

Realize I'm bumping an old thread but I just purchased a used Yukon XL with the 6.2L and 62k miles and 10 speed transmission. I noticed this 'pulsing' when driving it 7 hours back home on the highway 70-80mph. This is my first time driving the 6.2L. Did you ever find a fix for your issue? Is this a common problem? As the OP mentioned, feels like the transmission is slipping...

In full disclosure, I'm looking at a 2020 Yukon XL. I posted in this forum as it appears to be much more active than the Yukon / Suburban forum and I was hoping to get a handful of responses from owners with 2013-2016ish trucks who might give me a sprinkle of hope that this suspension isn't just expensive trash.

Though really the root of my question relates to whether there examples of MagneRide suspension lasting >50-60k. I realize its expensive to replace and honestly if/when I replace I'd switch to Fox or something simple. Not here to debate ride merits. Not here to debate whether its expensive or not. Just here to learn if there is a chance I'll hit 100k before needing anything or if by purchasing it with 60k already, I'm facing an immediate suspension bill. Thanks all!

I've got enough forum experience elsewhere to know what this means.... Though this implies that there is a group in the pro-MagneRide camp..?

Hi All - former owner of the other brand, I have an opportunity to buy a 2020 Denali w/ 6.2L and 60k miles. I am trying to learn as much as I can about the GM platform as this is my first GM. Wonderful forum here. I'm struggling to find anything that says "I have 100k+ miles on my MagneRide suspension". How reliable is Magneride? Everything I'm reading relates to Magneride failures and people swapping Magneride for more traditional suspensions. It is just assumed that MagneRide needs to be replaced every 50-60k? Looking for any comfort that MagneRide is worth it and is not an absolute pain in the rear. I keep trucks for a long time and would hope to drive this one for 200k+ miles but if its going to cost $3-4k every 50k miles, I might go another direction. Fwiw my current daily driver I bought 20 years ago, summer of 2001, to give you a sense of my ownership style. Thank you in advance for any help!