thekcwolf

Yeah, It certainly blows having to keep your fingers crossed, so that you get to where you are going. Those knocking/metallic noises... I always had the understanding that was typical with these direct injection engines. Something about oil settling lower than in a non D.I. engine, so it would take a few minutes for the oil to warm up and get distributed around critical parts to at least quiet it down... (something like that), which would also explain the prominence on chilly mornings. Also probably why they suggest full synthetic oil. Well, anyway... Thanks to you as well for continuing to update your story. Aside from being able to learn a few things on these forums, it certainly eases the repair anxiety for the rest of us. Good Luck with all the new lifters, You should be okay. See you around ! Cheers, Tony

Dave, Having taken delivery of a '21 AT4 with the 5.3 and knowing the engine falls inside the affected date range of faulty lifters and rods and springs and rear window seals, I've been following here anxiously hoping your dilemma had been resolved. I can only continue to drive with fingers crossed. Not so, on the rear window. After 1500 miles and driving in various degrees of steady rain, for the first time... It leaks. I am right along side of you when you say you won't piss and moan and can only give you a "hang in there, man". I traded a completely reliable Titan with 110k of my own miles, because "I always wanted a Sierra". I even had a deal in the works for a new T, but... "I always wanted a Sierra". I am almost hesitant to ask if you happen to know the production date of the engine in your truck, because I shudder to think it was nearly the same date as mine. (Feb 4, 2021). Ahh well. Keep us posted... I'll be watching, and... Hang in there, Man.

Dayum, BDogg... I actually thought this thread went dead. I, for one, really appreciate your follow ups. Good Luck with this. I hope it works out.

Ok, Got my AT4. Got under there and got an image of that decal on the engine. I have been everywhere to try and "decode" the thing. Which one of these numbers represents the "julian" date? It's probably right in front of my eyes. Help is greatly appreciated. Thanks! L84 210360788 CU7 12685254 002127157 1110000000000X T1210361CU7X0788 EDIT: Found a Julian Date Converter that jives. Also discovered these tidbits. *I read somewhere the T1 at the start of that code was designation for the newer body style. "T1 Platform" which replaced the "K2 Platform". T= Assembly Plant code. Which i assume is Ft. Wayne in this case. (I thought Ft. Wayne was a "Z" in the VIN.) 1= "First Shift" 21036= Year(2021) - Day of year(36th)... so (Feb. 5, 2021) The rest, although I am interested to learn about, is sequence codes (according to the other post). Hopefully the "Valve Lifter Service Update #N212353840" was performed prior to delivery. Cheers, Tony

I've been in waiting since September. You'll be lucky to find one at MSRP. Basically they offer "incentives". Many dealerships place a "Market Adjustment" on top of the MSRP which you will also be lucky, to chisel them down on that cost, too. There's an article about GMC warning dealers of price gouging, but in this high demand market, you're bound to see some sort of price increase. I've seen dealers with prices on AT4's that have less options, stickered for what I'm waiting for which has all the options.

Holy Cow.... That's a lot of errors !! Did you take delivery before the microchip shortage thing began? I'm wondering if the "newly processed" chips were manufactured poorly. When was your build date? (I've been asking that a lot).

Yes, there's a TSB out there. According to a request from "[email protected]", this vehicle was in an intermediate delivery status in Ft. Wayne. I hope you're right and I'm also hoping the dealer has something that tells me the work was performed, because that would ease my concerns.

I'm more "concerned" about the fact, that this thing has been sitting around somewhere since February/March of last year and will STILL have these major engine problems !!

What Year/ Model/ Build date is your vehicle? Does it return to normal when disconnecting from Bluetooth?

@Sharon Davis, Please do, come back and let us know what happened. What was the build date of your 2020?

Hey Now !! @WeGone Where is this Decal/Label/Sticker located? It doesn't look to difficult to see from "open hood" view. Interesting to see when looking at a new vehicle that's on the lot. Thanks !

Comical ad campaign !! Walter seems to take direction well !! That actor played a detective character in "Dope Sick", on Hulu. Also does commercials for (I think), Sprint mobile.

The high demand and the fact that there is no "market adjustment" on the vehicle I am waiting for, makes me want sit tight on it. I've seen other MUCH LESS equipped AT4s on the Build and Price/ Dealer Locator pages, listed near or above what this guy quoted me. That "build date", tho... 2/21... It's 2/22 now !!

This is why I love these forums. here you have a group of folks that are all trying to decipher a circumstance with the sole reason of finding out much desired info for the greater good ! well done. I'm VERY curious to know how many "Valve Lifter Failures" there has been, in engines that have the Pulsar units installed. Is it still happening? A bit of background... My (potentially mine), '21 AT4, with, get this, a build date of 2/21... ***YIKES*** is supposed to be at the dealer by next week. It's a 5.3 with DFM and Auto Stop. Other than chip shortage issues, No idea why it has been sitting so long.

Yeesh, I love these forums, but I hate these forums. All this discussion about failed lifters and such, really make it difficult to want to go through with the purchase of this '21 I've been waiting on. Dealer says it will be here next Monday. I know, I know... Not every '21 will have these problems but ... I'm not the gambling type. I want to get in, start it up and go. period.

Check out this screen grab from https://tiresize.com/comparison/ Notice the "speedometer error" chart. I think maybe the only problem you'll have is some rubbing that can easily be taken care of... Go for it !!

Can I even share this screen grab?? Just thought this was interesting enough to share and make for a good discussion. I know this isn't a live aerial shot, but check out all the vehicles at the Ft. Wayne plant. Cheers, Tony

Kinda feel that way, but damn, It's so close. I'm at least going to have a look at it. Maybe they will offer some other incentives and it will drop the price a few more dollars. I also feel like this thing was held up somewhere so they could do all the factory corrections before getting it to customer. Fingers crossed. we'll see what happens. Maybe I'll hold onto my trade, in case of some catastrophic failure!

It's a method that's been working for centuries ... "If it's leaking, tighten it"...

Ahhhh, the oil filter discussion !! There's one in every forum !! It's as old as the "it's sauce... not gravy". argument !! All joking aside... I'm new to this site's forums but not new to servicing my own vehicles. Fram gets pooh'd on, every time by many folks, but I have over 450k miles on Fram filters, (which doesn't seem a lot, for the amount of years I've been behind the wheel). I change my oil regularly, most times earlier than recommended intervals. Never had a problem. I'll probably continue to use them on my '21 5.3L AT4... if it ever gets here ... Cheers, Tony BTW... I call it "Sauce", UNLESS you're adding the meatballs and Sausage... then, it's "Gravy".

This is the type of thread I searched the forum for. I've said in my "intro", that I'm here honestly to have my fears calmed in regards to my "Sierra in wait". There's 106 pages of solid info here and I'm eager to hear the forum's opinions and hear from some folks that may have a Sierra from the same build date, time frame. Long story, short as possible... hopefully. Sept 2021. Finally found an AT4 online, "in transit". Clicked the "get e-price" link and receive a response of what I was hoping to hear. The number I saw on the dealer's web page was the number he quoted me. Minus taxes and 'conveyance fee' of course. Got in touch with him and he spelled it all out over the phone. Called back that evening and when the guy told me it wasn't spoken for yet, I gave him a deposit. Everyone who's looking for a vehicle during this time is/was aware of the chip shortage. Meh... I can wait. Fast forward to Dec 30th, when I come to find out the vehicle was built in February of 2021 and is currently in a "intermediate delivery status with no estimated delivery date". I start to think about this truck sitting in an Indiana parking lot for 10 months. Who knows what could have eaten what, where, right? Jan 4, 2021, I call and discuss my concerns with my salesman. Jan, 7, I call and (painfully) request my deposit be refunded. (side story there, but, some other time...). Jan 15th, dealership calls and tells me it's on it's way... it will be here Feb. 17th. (Currently now, by the 7th). I'd appreciate any Input from the forum in regards to... -Why (aside from chip shortages), would this thing still be sitting around 7 months, (now 11 months) after it was built? -Why would anyone want a vehicle that has been sitting around for that long? (Does it matter?) -Would it be a reasonable assumption that the "Valve Lifter Service Update #N212353840", was performed? -Would it be a reasonable assumption this vehicle now has a non DFM engine? -Would it be a reasonable assumption there are various components/features that have been credited? like... Heated steering wheel, Rear heated seats, HD cameras, etc. (even though the dealer told me otherwise). -Would it be a reasonable assumption the dealer is full of ???? ? These happen to be questions I've asked the dealer, with no definitive answer. Vehicle in Question ... 2021 AT4. 5.3, Value pkg, Tech pkg, Driver Alert 2 pkg, 20" Thanks all, Tony Cheers!

Hey Now !! I've been reading this forum since last September when I left a deposit on a '21 AT4. Since my Sierra is currently "on it's way" right now, I'm here (honestly), to calm my fears regarding the many valve lifter failures and engine problems that are currently plaguing the vehicles built during the 9/20-3/21 time frame. It's nearly ten years since taking delivery of what I currently drive, so ... to say the least, I'm excited!! (and a bit anxious). Talk to you later !! Cheers! Tony

Exactly my current dilemma. As for the rodents... Tomcat makes a spray that I have been using on a Kia that is parked outdoors. https://www.lowes.com/pd/TOMCAT-Rodent-14-oz-Rodent-Repellent/1000763452