Another JR

Grommets with the right cement should be perfectly fine.

Do you have the second key fob? If so, wrap the one you have been using in foil or take it to 100 feet or more away from the truck. Drive the truck with the other fob for a few days to see if it still happens. If it appears to be caused by the fob, maybe the button is stuck on (I think it’s the unlock button that lowers the windows if you hold it down). I have had that happen a couple of times on other cars due to the button getting pressed by something in my pocket. More often the panic alarm has been pressed. I try to carry only the fob in that pocket now.

My truck is probably one of the most babied and best maintained out of all the individual trucks discussed here. Premium fluids used, very short fluid change intervals, indoor storage, waxed regularly, low amount of towing with easy loads, minimal off-road use, and most driving done empty or with an 1800 lbs (40% of payload rating) popup Four Wheel Camper in the bed. It’s driven to full warmup every week during non-use periods. All maintenance was performed by a roughly 60 year old mechanical engineer specializing in aircraft propulsion systems that has all the correct tools. You will not find a single maintenance record on Carfax for my truck other than the first oil change done at 300 miles due to my discovery of a dented filter from the factory or shipping. I have full personal records with receipts for fluids and filters. Anyone would be lucky to buy my truck used. Someone refusing to look at my truck due to lack of Carfax records would be missing out on a great truck. I’m not selling, though. My son will get it whenever I am done with it.

4 low is really nice on steep boat ramps.

I have no direct experience, but everything I have seen indicates Silverado and Sierra bed geometry is identical.

Keep in mind that anytime the dealer gets access to your truck they likely install any updates for software throughout the truck. It probably has nothing to do with this, but it’s another variable that should be considered in troubleshooting.

Some service advisors are clue-free. Others seem to feel an obligation to deny knowledge of well known issues. Some are very good. I received a total runaround from my selling dealer regarding the TSB for the transmission cooler bypass valve set temperature change, but usually they are pretty good. I still can’t get an audio file to upload, and I am not going to set up a YouTube account for it. However, if your truck briefly sounds like a diesel for 1/4 to 1/2 second very shortly after it starts, that’s the oil pump priming issue. It occurs after extended shutdown because some oil drainback occurs creating an air gap in the pump intake path. It is normal, it occurs more in colder weather and with longer shutdown times.

Did you note the engine and transmission temperatures when this occurred? It could have been a high temperature protection mode. My other guess would be the 10 speed transmission valve body failure issues (hopefully not), but if temps were high while towing and it later returned to normal, it may have just been an overheat protection kicking in.

I took a 12 second video on my iphone but the file is too big to upload. I will have to figure out how to extract the audio or just do another start with an audio recording.

My plans changed today so I haven’t had a chance to record a start yet. This is one of the threads I recall, but you were involved so maybe you already reviewed this one:

Oil pump noise was discussed before. I will try to remember to record a remote start later this morning.

I don’t have detailed measurement data, but this past March we were hiking and camping in Death Valley and the Las Vegas area when this Spring’s heat wave hit with 105 plus temperatures and our 2021 L8T system kept our crew cab as cool as we wanted it (68F setting) with no trouble. Fan flows on auto once stabilized were fairly low. It seems like the OP’s system should be performing better.

Are you going to take long trips in it? If so, try out the seats in the various trims. For me the lower trim level seats were not comfortable.

I have had the same suspicion that some of these single use bolt installations are not actually torque to yield. In this case, the size involved and the initial torque, plus the additional rotation angle, don’t seem to be enough to be causing yield. However I have not done the actual calculations. One reason to use torque plus angle when not intending TTY is to reduce variation in the clamping force due to thread or head friction.