20L8TSierra24

Apparently it's fairly common. Service bulletin for those that need it in the future.

21 Yukon 5.3, 38,500 mi. Other than minor things, I just took mine in for rear end issues. It's locking up at slow speeds for the initial 1-2 miles ea morning.

I honestly think the current front end looks nicer. The interior is a step up though.

I have a 21 Yukon w almost 40k miles on it now and the rear end is having issues. At slow speeds after the vehicle has sat over night, the rear end locks up until we get a mile or 2 on it. After that, it drives normal. It makes a grinding whining noise like a 4wd making a 90° turn. Fluid was full as well. Dealer called and said only the fluid has to be changed and no damage was done to the diff. I would've thought after all the grinding and whining noises sometimes would've been damaged. Is changing the fluid only putting a Bandaid on it?

Bingo. Can see it in his picture.

Well that really sucks. I responded earlier in the thread and my lifers on my l87 were all done at 8400 miles. Now, it's making noise again at 20. GL & glad it was still within the warranty.

Both of my 22 trucks made made this clicking noise and it was the transmission support crossmember/mount. Dealer torqued all bolts and fixed it both times.

Add me to the list. 8400 miles on my 6.2 and all 16 were replaced last week. Dealer had the vehicle for a week and all sounds normal now. Mine knocked real bad every morning from both sides of the engine.

Never thought of that. GM forced me into 3 yrs so thanks for the tip!

It was changed at 1500, 5k & 8300. I use the PF 63 and Mobil 1 oil. I switched to valvoline the 3rd change hoping it would improve the lifter tick but it didnt.

Picked up the truck today. Engine Sounds normal for the first 2 cold starts that I've done. No abnormal noises and it seems to be Idling a bit smoother but that may be just me. Dealer replaced all 16 lifters and their guides too. 20230510_145932.heic

Engine is getting a full set of lifters next week. Service manager and I went out for a cold start this morning and he said it's definitely not normal

I don't know. It's at the dealer now but I picked it up the day it hit the lot which was 9/26/22. It's likely 1-2 months prior to if I were to guess.

Drove by my dealer this morning and he said they're dropping like flies still. He said I have to drop it off next week at the end of a day and they'll give me a loaner. It will need to sit overnight like the bulletin states so they can get a morning cold start. He said it'll get a set of lifters by the way all my videos sound.. He joked and asked if I had a CEL light yet and when I said no, he said I will soon.

I don't know what happened here... can't delete either

https://youtu.be/t9UFIEB1TWI What about this sound?? Every cold start, it's developed a LOUD ticking/knock noise also. It started around 7k miles. It has 8400 now and 483 Engine hours. It used to be only the first start of the day but now it's every cold start. Today's cold start

I got bird doo on mine today while I was at my son's baseball game. In the 2 hours we were there, the doo baked on and etched into the paint so bad it needs to be polished out... I also had a black AT4 that GM bought back because the whole truck needed to be repainted because of contamination.

I have what I swear to be an exhaust leak from the header or where it connects to the cat but the dealer said it's a normal sound. I don't hear it at idle but under light acceleration or deceleration, it sounds like a 20 yr old Ford work van. Anyone have a similar sound that's apparently normal for a 6.2?? I also have a loud lifter ticking/knocking noise. It happens every morning and if I let it sit long enough during the day. Thanks in advance. Here's a video of the lifter noise. https://youtu.be/t9UFIEB1TWI

It has made it 75k miles. Seems like most fail within the first 10k if they're going to.

2/27

I had an 16 LML & 21 L5P and chose to order a 24 6.6 gas myself.

I told my dealer exactly what I wanted and on Thursday the 19th, he said he'd be able fo submit my 24.

I told him what I wanted, he said I was good to go for the 19th. No pricing yet, just able to see the order guide and options on the dealers end right now. The configuration tool should be live any day now too

I ordered a 24 gas AT4 yesterday. We built it today at my dealer and it'll get submitted on the 19th. I had a 21 L5P and it was nothing but check engine lights and I traded it on a 1500 6.2 while it was in the shop waiting on a def tank. My 2016 LML blew a HG, Coolant tank, 2 water pumps, and a DPF... I'll miss the raw power of a diesel but actually looking forward to the simplicity of the Gas truck with the 10 speed behind it. I towed my 2755 Coleman travel trailer 800 miles and it was a white knuckle ride even with a WD hitch. I thought I could get away with it but it's just not safe.

Man, you got lucky that it was just the grill. If it was me, I would have the whole front end smashed in given my luck