WeberKettleGuy

I've just recently inherited it a few weeks ago. I'm sure it was babied by my father in law. I've been running it pretty good over the last week trying to "clear the rest of the cobwebs" out of it.

I didn't even think to check the owners manual for plug numbers. I'm certainly going to keep after the oil consumption monitoring, if there is any. Oil catch can was installed last week with oil change. I'm happy to hear that the small amount i have is nothing to worry about. Also didn't realize the heads had to come off to do the lifters. Thanks for the response!

Hey all, If you've seen my other posts, you'll know I've been chasing a couple issues with my centennial edition Silverado that are now fixed. The truck only has 7600 miles, and had a misfire a couple weeks ago that ended up being a bad spark plug. The GM dealer changed plug #4 and wire per the service writer and receipt. Misfire fixed. They recommended changing the rest of the plugs, as well as some injector cleaner since it's sat a lot. Here is my story. After the original trans fluid was exchanged per the TSB last friday, and the shudder fixed, the truck still seemed to have a very minor miss here and there. I bought a bottle of injector cleaner (redline si1) and dumped it in today on my way to buy plugs. O'reilly's website showed two AC Delco plug numbers for my year and engine. 41-168 and 41-114. Per the website info, they have different heat ranges, and the 168 has a platinum ground electrode tip, the 114 has a iridium. I didn't see any other differences, doesn't mean there aren't. I called the GM dealer, and according to their computer, the only plug listed for my VIN is the 41-168. When I gave the parts guy the 114 number and asked what it was for, I was told it spec'd to 23 and newer 6.2L engines. I have no way to verify this, just what I was told. The guy beat O'reilly's price on the plugs, so I bought 7 and drove on home. I stared with the passenger bank, changing all plugs from the top. I can see why they say removing the inner fender and wheel would be easier, But I managed to get them all from the top without too much issue. #8 did require a wobble/universal joint instead of the short extension. I highly recommend a magnetic spark plug socket if you don't already own one. I laid a folded painting drop cloth over the top of the engine and radiator for comfort. There was honestly much more room than expected. When I pulled cylinder 8, and it was a different number, I started to wonder what was going on. so far, cylinders 2 and 6 had 41-168 plugs. I skipped #4 because it was changed..... allegedly. After pulling the drivers bank and finding 1,3,5,7 all had 41-114s in them. So I pulled #4, and it was a 41-114 as well. So yeah, I'm confused. I replaced all the plugs with the new 41-168 plugs, and reinstalled the 41-168 from cylinder 2 into cylinder 4 to make a matching set. My first thought is I was surprised to see oil on the threads, should I be at all concerned? Also curious about the tip of the center electrode. I did my best to take a close up picture. It's been a while since I've been in a gasser, is this normal electrode appearance after use? Test drive went fine with no issues. I'd love to hear from you all on your thoughts as to why there are mismatched plugs in my truck. I could see the tech swapping plugs around to rule out a bad coil, but unsure why he would have replaced 2. Maybe he broke one? I'd also love to hear from anyone that could clear up the two different plug numbers and differences in each. More info on the truck, a different GM dealer replaced all the lifters last winter due to a collapsed lifter. Maybe that has something to do with the odd assortment of plugs. If a lifter fails, would or could that cause a plug to foul? Looking forward to any information you all might have. Thanks!

Repair update! Truck went back to the dealer Friday. Tech took it for a drive to ensure there were no more misfires, and finally agreed with me that the torque converter was shuddering. Trans fluid was exchanged via the TSB. My bill out the door was right around $300, which honestly isn't too bad for a case of trans fluid and not having to mess with it. Truck immediately drive better, with no noticeable shudder after only a few miles. There still seems to be a slight miss from time to time. I'll end up changing the rest of the spark plugs out soon, and the tech also recommended running some injector cleaner through it since it has sat so much. Appreciate all the recommendations and information from you all! It's nice to have the truck issue free.

Jim, Did you ever find any more info on the total number of centennial editions produced? I totally saw our doppelganger this morning when dropping the kid off at daycare, we met at the intersection. There is another centennial edition Silverado within a few miles of my house. I'm gonna have to track him down for some photos.

Glamour shot

A beautiful day in Mid Missouri! Got the truck into the garage and changed the oil today. I'm not 100% sure, but it appears the oil didn't get changed at the dealer when the lifters got replaced last winter. If they did, that oil was dirty and they forgot to reset the "oil life counter". I'm not really surprised by anything these days. I was able to squeeze under the truck without ramps or using a jack. Pretty easy compared to my previous truck. So I drained the oil, and opened the hood. Much to my surprise, the passenger "valve cover cover" was lying next to the driver valve cover. The dealer just got done changing out plug and wire for cylinder 4, guess he forgot to put all the pieces back. Luckily it wasn't close enough to the manifold to melt or catch fire, Yikes! Installed Wix filter and 8qts Mobile one truck and SUV synthetic. Oil catch can installation was a piece of cake. I ended up purchasing one from UPR. Ran a little over $200 bucks since it was purchased with the drain line. They offer a 10% discount to military and first responders, so that was pretty nice of them. I skipped the drain line install for now, not sure if I will install it down the road or not. It's plug an play, I did have to remove the airbox to get to the lifter valley PCV valve connection. All hoses that come with the kit are quick connect, and instructions were very simple to follow. It's all black, and blends right into the engine bay. Very nice kit. Then she got a nice bath. I wasn't crazy about this color at first, but it's growing on me. Took a few pictures down at the big burr oak tree. If your familiar with Columbia MO, you know about the tree. Speaking of Columbia, saw my doppelganger this morning! Met another centennial edition in the babysitters neighborhood this morning (off Southhampton). Would be neat to get some photos of both trucks together.

This is very helpful. Thank you very much!

After reading the sticky about changing fluid and flushing, It sounded like the flush on these trans wouldn't work like it used to on older models. I suppose I need to do more homework and ask more questions. And I don't think you're being an Ahole, you make a valid point with timeframes. My view on this is it's a known issue, and should immediately pop up in the dealers computer when the VIN is ran for repair. GM knew it was an issue and issued a TSB to correct it. If it was anything to do with safety, it would have been a recall, not a TSB. The truck went into the dealer last winter and had all the lifters replaced due to a single collapsed lifter. That would have been the time to catch it, however I don't know for sure if it had the shudder. It was first noticed by my father in law when it came home from that repair, but wasn't ever driven afterwards until my father in law passed away in June, which was the first time I drove it. The warranty I have on it is an aftermarket warranty, not a GM extended warranty. I did not purchase the truck as a "certified pre owned" or anything to that effect, so no chance of having any GM warranty left, since the original purchase was back in 2018, all the GM warranties have expired. The aftermarket warranty was purchased at that time, and is a 96 month warranty.

Repair update: it's fixed..... kinda.... The service writer that I communicated with was very understanding, and I do feel gave me the time of day in my concerns/complaints. One plug and wire later, the misfire is certainly taken care of. Bad plug was in cylinder 4. The tech swapped the plug and wire to another cylinder to rule out a bad coil, and misfire followed the bad plug. Again, I'm shocked that a plug with only 7k miles is bad, but it is 7ish years old. So $370 later ($150 diagnostic fee, $150 labor rate and the most expensive spark plug I've ever paid for in my life), I have it back. Service writer and two techs (one being the transmission guy) ensured me that there is no issue with the trans and torque converter. They all drove it, putting 10 miles on it. After I drove it home, I still have a low rpm/low throttle shudder around 50mph once the truck is up to operating temperature. I'm on the fence about taking it back, but I'll probably just start with changing the trans fluid myself. No way I'm paying them the crazy rates for a fluid swap, especially if the warranty company is gonna pull the "maintenance item" crap again. I'm also gonna change the other 7 plugs and wires just to rule them out, since one went bad already. Side note, they wanted another $300 to change the other 7 plugs! And of course the aftermarket warranty didn't help, since plugs and wires are a maintenance item. At least my insurance company will take care of the tow bill. As far as the TSB and customer pay stuff goes, My two cents is GM should have taken care of it and just changed the fluid. They know it was an issue, but want me to be stuck with the cost? Not cool. Even if the dealer has to "take care of it", I'm sure there is some reimbursement from daddy GM somewhere. At the end of the day, this is one of the many reasons why people hate using dealerships for their repair work.

Thanks for the replies! I tried to reply last week, but the forum was being wonky. Anyways, I was going to take it to the dealer last week, and it started misfiring, real bad. Bad enough to trigger the flashing check engine light. So I called the warranty company and the dealership. It was towed yesterday morning from my driveway, I just don't want to chance any more issues on the drive over. This is my first truck with AFM, and even with the lifters just being replaced 500 miles ago, I'm worried the misfire is more than a coil or plug. When I spoke to the service writer about getting the TSB done on changing the fluid, He said that it's out of warranty. It's been a minute since I've had to deal with a TSB, but if it's out of the factory warranties, can the dealer opt to not perform them? They want like 300 dollars to do the flush and change out of pocket. In the end, I guess the jokes on them since they will have to deal with the warranty company and figure out what needs to be done. I just hope they spend their time on it and don't run it through like a cattle barn. I'll keep you all posted. It's not "scheduled" to be diagnosed til friday.

Truck has a low throttle shudder, certainly feels like a torque converter shudder from my experience with vehicles. This is a 2018 Silverado 6.2 with the 8 speed auto. The truck only has 7500 miles on it. I called the dealer today to inquire if the transmission fluid was ever replaced under the TSB, and it was not. The truck is out of all the warranties except for the aftermarket warranty we still have on it. When I inquired with the service manager about doing the fluid flush, he said that his experience with these, the torque converter is already damaged. The service manager said that the warranty company would probably replace the entire transmission. He then asked how many miles were on it and was noticeably shocked when I told him 7500. Then he remembered the truck because it had all the lifters replaced under warranty 400 miles ago. So, Do what do you guys think? If the warranty company wants to replaced the entire trans should I let them? Do I have a choice in the matter? and will it be a new trans, or a remanufactured unit? Of course the truck will have to go to the dealer and get diagnosed, but I'm pretty confident we all know the issue is from the original fluid never being replaced.

I need to get it to the shop for a trans flush, it already has the torque converter shudder. Hoping not much damage has been done. Silly question, where do you find the production number? I've yet to find anything in my truck that shows it was numbered, however with a toddler its hard to find time to really go through the truck.

Hey everyone! I found this forum after doing plenty of engine research on my "new to me" truck. Long story short, We half inherited/half bought my father in laws 2018 Silverado LTZ Centennial Edition. Truck is near mint, only has 7,400 on the odometer. My father in law kept in garaged and didn't drive it much, but it was one of his most treasured gifts. My wife wanted it kept in the family and couldn't stand to watch it go down the road, so I sold my Cummins swapped 04 Super duty and ended up in this. We just straight up didn't have the room or time to keep both. I've not had a gasser for my daily in 20 years. I will say, this 6.2L is a blast to drive, and has a lot more creature comforts than my Fummins did. I've already got a catch can sitting on the work bench that will probably get installed next week, once I figure out where I want to run the drain line to. The truck went to the dealer last year and had all the lifters replaced after having a lifter fail. I was shocked that he had a lifter fail after only 7K miles, then I started to understand why after doing my research on the engine technology. Thankfully it was covered under the aftermarket warranty, and I'm thinking I'll be getting one myself. I will say it runs great at the moment. Cheers!