martinto

Pull behind Travel trailer.

5000 - 6000 range, or when I hit 20% oil life on the algorithm. I sometimes pull a TT, so it varies. 0 - 20 synthetic at dealer.

Update to 4th time AFM lifter failures. Dealer service techs have replaced both banks of lifters, push rods, camshaft, VLOM and associated parts. Two techs and service mgr had requested to GM to replace the engine. GM and 3rd party warranty both refused replace…only approved repair with latest design parts. Previous repair process was only on failed parts. Now includes VLOM. Requires cam inspection and replacement if wear is evident. $7000 in repairs covered by 3rd party warranty. 42,000 miles on this truck; now to see if this fix works. My warranty is good for 100,000 miles or 2026.

Update to 4th time AFM lifter failures. Dealer service techs have replaced both banks of lifters, push rods, camshaft, VLOM and associated parts. Two techs and service mgr had requested to GM to replace the engine. GM and 3rd party warranty both refused replace…only approved repair with latest design parts. Previous repair process was only on failed parts. Now includes VLOM. Requires cam inspection and replacement if wear is evident. $7000 in repairs covered by 3rd party warranty. 42,000 miles on this truck; now to see if this fix works. My warranty is good for 100,000 miles or 2026.

Read up in VLOM…thanks for the heads up. Could be a contributing factor in the failures. I’ll be discussing with dealer service.

Thanks. That is where I’m at. Dealer says the cam shaft is damaged and needs to be replaced as well. I question the durability of the engine given the history. I requested what options to consider…extended warranty, which only covers cost of repair but at a cost of inconvenience, or should GM drop another engine in. I’m sure there will be push back on either. My service guy understands my concerns and is working to find an acceptable solution. If he runs into a wall, I will need to escalate.

Agree

Oil changes by the dealer at specified intervals…with synthetic. All my maintenance is done by dealer service. When my tranny had the famous shudder, they followed the TSB with the new Mobil Blue fluid. No problems since then.

OCI? I’m taking the position the given the frequency of failures…GM needs to step up. May need the extended 3rd party warranty for other issues. Given they now need to replace the cam shaft as well, big bucks on the horizon to the 3rd party or GM.

Thanks. Don’t know what that is. Not noted on the invoice summary. Today they advised they need to replace the cam shaft. I’m pushing back on what all these failures and repairs have on the engine reliability. Only 48,000 miles

First of all, I love my Sierra...except for the repeated lifter failures. New in 2016, cross country trip and first failure on #6 lifter & pushrod damage; dealer in Iowa fixed in short order. 2020 another failure, but tech didn't indicate which lifter failed, I should have confirmed. 2021, #4 lifter fail and pushrod damaged. This week, #4 again. Dealer is doing a deep dive to investigate how deep the damage may be. Warranty has covered all fixes and I have extended warranty, so $ not the issue at this point. What concerns me is the frequency of failures and how that impacts the life of the engine. Has anyone on this site experienced these repeat lifter fails? I'm thinking to reach out to GM and request of review of the failures and what consideration can be given; i.e. replace the engine??? Dealer has been great, but I don't look forward to repeats every 1.5 to 2 years. Thanks for any feedback.

Had the shutter on my 2016 Sierra 6.2l 8 speed tranny at 32000 miles. There is a TSB to change tranny oil to a special Mobil 1 Blue. Shutter gone. I pull a TT from time to time so I plan to change tranny oil every 30,000 miles or so.

2016 bought new, came with Goodyear Eagles “P” spec. They have been good tires. Went cross country pulling a 7000lb TT. No problems. Getting a set of Michelin Defenders “LT” spec. Yellow tag in door jam says 32psi front, 35psi rear...when not towing. Should the psi be increased on the new LT Defender tires? Towing I run near max.

2016 Sierr, 6.2L with max tow package. I did the tranny fluid drain and replaced with Mobil Blue special under warranty at 33,000 miles. This was per the TSB noted by reardiff. I was getting a periodic shudder. The tranny fluid change made the difference....no more shudder.

GB, sorry Sir. I thought you were making a statement about me with your post reply to my 1st post. I get it now.

Hey GB, thanks for sharing your expertise. I'm pleased to learn that after 40+ years in manufacturing critical components for turbine engines, industrial engines, automotive engines and motorcycle engines, that there is no variability in such components. That an allowance for a tolerance band is to deny the "exact measurement & calculation" of an ECU. I now wonder why I've seen failed ECU's under warranty returned for replacement when errors were validated. Not sure what lie I've shared as you've stated above in your 11:06PM post. I also have a tolerance band, sometimes I'm in tolerance and correct, but sometimes I'm out of tolerance and I'm wrong, so my statements may have elements of "error" that can be challenged. I applaud your defense of all things ECU & OBDII; spot on Sir.

If your speaking of manufacturers reported mpg, that’s an optimized result...special formulated fuel and a host of other conditions in establishing the numbers. I worked at both Honda of America in Ohio & BMW Mfg’ing in South Carolina. My actual mileage on my Sierra runs within 10% difference with the vehicle display. The algorithm that does on board calculation has +/- variability, so it’s not likely to be dead on. Running with my 6.2L max tow pkg, so my mpg is what it is.

Where did you get the set? I only found ones with "6/2L...LS--". Thanks

2016 Sierra 6.2. At 30K miles I would have a periodic shudder (like rumble strips). Got the TSB, took it to my dealer,. The TSB calls to change out the Dextrose tranny fluid with special Blue Mobil 1 fluid. It works...no more shudder and-last week, I pulled a 6500 lb travel trailer in the mountains, with no reoccurrence of the shudder. May consider changing out the tranny fluid every 30K miles given I pull a travel trailer.

Was the fluid swap to BlueMobil 1? Just curious.

Had the shudder at about 33,000 miles. There is a TSB from GM that outlines a change in transmission fluid from Dextron XX to a special formulated Mobil 1. My dealer did that under warranty. It’s been 3 weeks and no shudder. I’ll be pulling my travel trailer in a couple of weeks and will see how it does under load.

Thanks for the insights. I’m aware of those posts, TC and fluid change. Was also thinking about injectors which seems to be a current topic On the forum. Regardless, need to get it into the dealer. I’m lucky to have a good Dealer service dept. still under power train warranty.

2016 GMC Sierra SLT 8 speed 6.2 Max Tow Pkg with 33,000 miles. Just started experiencing a significant shudder at various moderate speeds around town. The shudder shakes the vehicle for just a few seconds, and then it’s gone. It is now happening more frequently. I can’t tell if it’s at shift points or not. Anyone here have this experience?

Just wrapping up a 7000 mile trip across the US in my '16 SLT...towing a TT. The seat comfort has been great. I'v adjusted a couple of times over long stretches and that keeps me in a comfort zone. I do use a small cushion for my lower back to increase lumbar support. I've had to do that with other vehicles I've owned. These seats are actually more comfortable than my 2008 Yukon Denali, although that was probably due to aging.

Re warranty and/or recall on the 8 speed. Has anyone seen the TSB or have info on a recall...build dates, VINs affected? Towing cross country next week and while the 8 speed has been doing well both daily driver and towing, wondering if my truck is in the mix? Looked at my truck VIN on MY.GM and states no recall on my truck. Time lag or my truck isn't in the mix?