Kaze Morrissey

To keep things updated, it’s now the three month anniversary that my truck has been in the shop. Once they put the new engine in, it’s been nothing but replacing sensors and fuel balancers. It seems that they only replaced the engine and I am “assuming” that all the ancillary parts and sensors were kept from the old motor. I hope for the rest of us, I am the only one that has this issue. GM hasn’t reached out and I’ve already started the process for lemon law. Dealership has been commendable in keeping me updated with each new part they’ve been having to order and install, but I think this truck is done and has been unfortunately for quite some time. thanks for all the input.

Dealership was told to not tear into the engine and is just going to swap it out for a new motor, so I may never know what happened.

Yeah, that’s what I was thinking as well. Hoping I can get an answer as to what happened. Don’t quote me on this, but it sounds like GM is asking the techs to not tear apart the engine and just send the whole unit back to them to tear into. I’m not too surprised that they don’t want the local mechanics to tear into the engine before they have a look at it themselves.

Here’s a video of the noise it was making right before it died along with the vibrations. The oil was changed by the dealership and I drove it around for another 50 miles of commuting before this problem arose. I do love the truck and hope that this does get resolved. I did check the oil level and that was in spec on the dipstick, couldn’t confirm the oil type (haven’t calibrated the taste buds to oil type yet:). I had done my own break in oil service at 500 miles before I started any towing as recommended by the owners manual, so I knew it had the right amount and correct oil prior to the dealership as I put in only the GM oem oil and filter. The truck was being driven in between 70-80 temps when I started off and while I do understand that the incorrect oil would be bad for the engine, I don’t see how it could’ve caused this noticeable problem that quickly. So far haven’t heard much from the dealership beyond that GM is going to replace the engine. One service rep thought it might be a lifter, but don’t see how that could’ve caused the vibrations. Dealership said it’ll probably take to the end of the month for me to get the truck back. Currently they’re working on a loaner for me. Hope this helps any of you guys out there. I do think it’s a great truck and loved the motor when it was working. Again, there were no warning lights and all the oil pressures and temps looked normal as I was scrolling through them on the dash. There was a faint burning smell from the engine compartment after I opened the hood, but no over temps on any gauges or any other indicators of an overheating situation. Really bit of a head scratcher.

Was searching the forums to see if anyone else had this issue, but it seems I may be the first and possibly aware of a second to come across this problem. So, 2020 Silverado high country with about 6000 miles. Has towed a travel trailer all over the western US with no issues beyond pouring in a lot of DEF. love the truck. goes in for an oil change before it’s next big trip and have dashcam installed. Drive another 50 miles of commuting no issues. Hook up the trailer to head to Utah and start feeling a mild vibration 10 minutes into the trip. Think a tire went out, they’re fine, think maybe new spring bars on the WDH causing weird harmonics. Notice vibration is associated with engine speed between 1500-2000. Checked oil pressure, temps, everything looks normal, no warning lights. Then a noise starts like the cooling fan is hitting something. Decide to pull over, make a turn at an intersection, engine drops to idle then dies. Again, no warning lights. Go to start the motor, turned over a few times then dies as if low battery. Attempt another start, now it acts like the batter is dead and all power goes out. Doesn’t even turn over the motor. Have to call tow and get it towed back to dealership. its been at the dealership for over a week now. They went through all the electronics and can confirm that it’s not a dead battery. Been speaking with my service rep and he’s saying they’re in contact with GM. I’m suspecting the engine may have seized. Had video of the sound and shaking and a diesel mechanic buddy thought it might be a rod was thrown. After the engine stopped, I checked that there was oil in the engine and paper work showed the proper oil type. the interesting part was my service tech called in to say another truck had come in with identical issues. So hoping this isn’t a fleet wide issue. Will keep posting updates as they come. prior to this, hadn’t had any issues with the truck. Drove great, gas mileage was amazing, towed as if the trailer wasn’t even there. Hopefully will have some answers.

Yeah, good catch. The 144 lbs difference from the 6.2l to the 3.0l Duramax accounted for the difference in the GVW. The door stickers I compared were for a 6.2L 7100 vs a 3.0L 7200, but the 6.2L had 144lbs more payload. finally Figured out how to upload the files. So the first pic I believe is the 6.2L high country deluxe package and tech package, bottom pic is identical except for the 3.0L Duramax, both short boxes. Mind you these are silverados and I even found the GMCs will weigh differently, the carbon bed I think increases payload 40-50lbs along with possibly the carbon leaf springs, but the multi-functional tailgate adds a bit of weight as well. I’ve been banging my head against a wall trying to understand all these payload configurations and how they’re figuring them out

Yeah, I’m finding some discrepancies even with the door stickers. Comparing identical trims on a lot and a standard to short box showed only a 9lbs differnce, when everywhere else is saying it should be 50lbs. Good luck in your hunt. Your other option that I found was helpful was calling dealerships that had the trucks I wanted to compare and having them take a picture of the door sticker and sending it to me. Could help I your shopping if you’re that far away from dealerships. All the dealerships I spoke with were happy to help, but then of course I have been barraged with sales calls ever since.

To add further upon it, looking up that configurator calculator. Going to the 6.2L added 82.8 lbs on the front axle and 2.6 lbs to the rear axle from a base 4.3L 6 speed, I think, but the 3.0L added 183.6 lbs to the front axle and 79.8 lbs to the rear axle. I also leaned the difference in short to standard box is 50 lbs from the configuration page. I was in a similar boat to you, but trying to figure out differences in weight from a standard to short box. Hope this gives you what you were looking for. With that gm calculator, I just flipped through the screens to read the weight differences.

Yes, from what I understood, the payload was higher. Doing some more research on the forums, I came across this configuration builder that lists weight differences. This I found to be huge! https://www.gmfleetorderguide.com/NASApp/domestic/weightcalc.jsp#

Don’t know if this’ll help or not, but I was looking at identical specked Silverado high countries and noted a difference of 144 lbs if my math is correct. Both were identical except for the engines. They were 4x4 short box crew cabs. This was read directly from the “b” pillar door sticker. I’ve been able to call around and asked sales guys to run out to the truck and send me a photo of it.