ForestryGuy

Yeah I never really thought about it before and decided why not. Always been on top of maintenance so never worried too much. The thinking was also if I had a lifter going down I’d have some identifiable metal showing up.

I thought I’d share my UOA results and see what others experience is. I’ve owned my 2018 Sierra 1500 since new. 5.3l w/ the 6l80. I’m at 120,000 now and last oil change I sent off the sample to Blackstone to see what’s going on and if I had any metal or signs of odd wear. Oil changes were mostly done at my local dealer at the recommended intervals but since 100k I’ve been changing at every 5k. Disabled dod around 90k miles with Diablo tuner. I’m very happy to see the results that came through and will do another analysis with the next few oil changes so I get statistically sound numbers. In my opinion this is a testament to good maintenance and driving habits. This truck will be driven till the wheels fall off lol. Have others done UOAs and what did your results look like?

I feel like motors always have a little tick. The problem is when the little tick turns into a big tick that can be isolated to the valvetrain. It can be anything from a pulley bearing to AC compressor to one of the thousand other parts that are moving. I'm sure we've all heard the loud lifter tick in a youtube video that highlights the issue. To me its pretty unique. That said I got a diablosport tuner recently - turned off DOD, updated tire size and installed the firm shift tune in the trans. I wish I did this sooner, the truck drives way better now. I'm looking forward to keeping her for a while and modifying it a bit for trips in the desert.

Great points. You all have definitely validated my feelings towards the new offerings from GM. At this point I’m planning on keeping her running as long as possible. I appreciate the responses!

As far as maintenance goes, I’ve been religious about oil changes at roughly 5k miles or so. Trans fluid/filter was changed at 90k at the dealer. Both diffs around 75k, done at home - too long of an interval but what can you do, life is busy. I put delvac in there as penance. I don’t drive hard or in the city so lots of county road / rural highway miles and some cross country runs. She’s done some towing but nothing heavy or aggressive. Edit: I also installed the shift solutions thermo bypass kit a bit before the trans fluid change - don’t remember mileage.

That’s where my mind is too - get out while it’s got good trade in value. Sucks you have all those issues - sorry to hear that.

Hi All, Looking for some opinions and what better place to get them than the internet. I've got a 2018 Sierra 1500 SLE, Z71, with the 5.3 and 6l80. She's paid off and got 109,400 miles - zero problems (knock on wood). Its been the best vehicle I've owned by far and its set up just how I want it. Since its getting a little long in the tooth, I've been shopping around for one of these newer Silverados WT or a Sierra Pro with Z71/X31 (since they are more in my budget and still have 4lo). Current truck is a double cab and it would be great to have the crew cab but with the standard length bed - odd combo anymore. My reservation is that and I just feel like I'd be trading a good truck that's finally paying me back for something newer but with potentially other problems and a car payment. My analysis of what I need to do to the potential new truck to make it comparable with the options/mods on my current truck (lift/suspension, topper, air bags and accessories) is almost the cost of a new transmission - should that thing go. My goal for the Sierra was to take it to 250k+. I just fear a huge bill that wont make sense to pay on an older/high mileage truck. I've reached the point of overthinking and analysis paralysis so that's what is brining me here. Is anyone looking at the newer trucks? What are your thoughts on the 10 speed? Is it worth it to trade up?

Thanks for that info. This was a chill drive home with no aggressive driving. I’ll be driving up to the ski area tomorrow so I’m hoping this prevents the burning smell.

Resurrecting this thread to get some answers or reassurance that I made the right choice by installing the Shift Technology STL010 kit on my 8l90. The truck is a 2018 Sierra with 103K miles. I live in southern CO, it gets cold here but also gets hot in the summer. I do a lot of driving up mountain passes and towing a 6k pound camper. Driving up to the ski area Ive been seeing temps in the 190s and occasionally getting burning smell. Trans fluid and filter were recently changed at 90k by the dealer. Had them check it out recently and they said everything is good. No shudder no hard shifts - I think it drives pretty good for a truck with just over 103k miles. We've got a trip planned for spring break where we will be towing a camper across the southwest so this afternoon I installed the Shift Technology kit to keep my temps lower and hopefully keep the trans happy for the remainder of my time with the truck. I'd keep it to 200K or more if it will make it. Driving home after the install 28F outside temps and I am seeing trans temps 103-108F. Is this too cold? Shifts were a little more noticeable but not harsh. I am worried this is too cold for the trans - I don't want to create a problem but solve a potential one. Thanks!

Issue is resolved, I think. Turned out a plug wire gave up the ghost after our diagnostic test last night. My initial service request was plugs and wires. Service tech said wires were still good. I contend 2/3 of the issues would have been avoided if the wires were replaced with the plugs. Kudos to Town & Country GM in Alamosa CO. The service manager Frank and the advisor Joaquin are great guys who helped me out with diagnosing this issue. I’ll probably change out the wires to a new set of OEM if it happens again.

Looks like they used 19459511. Can they still get the 12622441 plugs?

Hi all, Im experiencing some issues with misfiring following plug replacement done by my local dealership. My truck is a 2018 Sierra 1500 with the 5.3L. 101,000 miles, never gave me a problem until I had the plugs changed. I had the plugs changed as PM, no issues before replacement. Picked the truck up tonight after they went over it again following the initial misfire issue, started driving home and misfire. No CEL but you can feel it. Back to the dealership. We hooked it up to the computer and noticed the #1 cylinder is misfiring consistently. We pull the plug and see cracked porcelain and carbon. Replaced that plug. Hooked it back up and put things looked good. Driving home I feel like there is another random misfire, I feel it while driving but no CEL. The service manager mentioned they had a few bad plugs recently. I thought I’d fire off a post here and see if anyone else has experienced problems recently. Dealership is taking care of me so far so not a problem but I’m perplexed why OEM plugs are giving me a fit. We didn’t do the wires with the replacement - mechanic felt they were in good shape and didn’t need to be replaced. Thanks!

I recently went with Cooper at3 xlt's on my sierra 265/70r18, E rated. Made in USA, really nice tire. Originally wanted the falkens, but they weren't available in the size I wanted, also made overseas.

OEM.

Just ordered a set of 10 ply Cooper Discoverer AT3 LTs for my truck in 265/70r18. They will be installed on Thursday, I'll be sure to post some photos. The size was recommended by the tire shop. Apparently 265/65r18 is an odd ball size for a truck tire.