T-Town-Z

I really have not read anything bad about the baby duramax, but recall something on-line, that the engine needs removed or something major, to change a belt or chain after 100k miles..... ??? I'd like to read or see more about that.

I'm considering a 2022 "Limited" Silverado with the diesel engine. I have not really read of any issues with it. Have I overlooked something, or has this engine just been that ultra reliable so far ? Does it have any faults ?

Mine started to smell musty within a couple months of when I I bought my truck. The dealership sprayed something in it when I first mentioned it, but it only lasted a few weeks. I tried the various A/C cleaning foams and sprays but just the same, they are just temporary. I now just take out the cabin air filter when it starts stinking and spray Lysol in there while the A/C fan is on, then shut it off a while and let it soak in. This has been my regular spring, summer and fall routine for the last 5 years !

Double check the battery. I checked mine with a volt meter and showed 12.something volts. Was having weird electrical issues. Finally pulled it and got it load tested and was just marginally bad. Changed it and all was fine afterwards. Seems these vehicles are hyper-sensitive to the correct voltage.

I started using it on my 2014 somewhere about the 3rd oil change. I took off my air intake tube and drilled a small hole into the top of, it about 2 inches back from the edge, where it is clamped to the throttle body. (First I found a small "cap plug" that would fit tightly into the 1/8" hole that I drilled) I spray through the hole I drilled, directly into the throttle body. Just before each oil change since back then, I spray the can of CRC GDI Cleaner into the engine as per the directions. My engine was just apart for a DOD Delete cam swap (due to another failed AFM lifter) , and while torn down, I looked over the heads. Surprisingly they had minimal carbon build up on the intake valves. My thinking is, either its been way over-exaggerated about the carbon build up, or this CRC spray actually works !

How true ! I'm sure that my AFM didn't save even close to the $3500 that I spent to fix/delete the system.

I have not heard of that yet. Do you mean like too much oil in the crankcase, or like air getting into the pressurized oil system somehow ?

Hey Grumpy, I guess you're one of the the lucky ones that hasn't had any major problems come up. I've previously purchased new trucks in 96, 01, 03 & 05. They all needed a few repairs, but not any high dollar expenses like my 2014 has had. Even with all the proper maintenance, my #7 AFM lifter went out at 55K, but fortunately the dealer covered it under power-train warranty, but would have been over $2500 if I had to pay it. This spring, the A/C condenser failed. That was $1100 out of pocket. A month ago the #7 AFM lifter failed again, even though the AFM has been turned off the past 40K miles. It cost me $3500 out of pocket for a DOD delete cam & lifter job. Yes, these new trucks are high tech, fuel efficient, and powerful. What I don't understand is, if GM see's repeated reliability issues, why keep building it the same way with the same parts ? They should't wait till the next major redesign in 10 years to fix it. Not everyone's AFM parts are failing, but there are enough owners with bad ones that you would think it should get their attention. It's not a good way to maintain brand loyalty !

$9K really sucks to spend on something this "new". I just got my truck back and cost $3500 for a full DOD delete cam, lifters, labor, plus a street tune afterward. It really aggravates me that GM keeps building this garbage !

Just going by what my truck has done and sounded like, it is a strong possibility that it could be one of the AFM lifters. Looks like you are probably out of warranty, unless you have an extended warranty. If no warranty, I'd suggest searching your area for a performance tuner, or shop, that is familiar with GM vehicles. Until you get another code that tells you that one of the cylinders is misfiring, it will take some diagnosing to figure it out.

The 2014 and 2015 Sierra stock headlights just outright sucked. They came out with a BCM update for the 2014's that boosted the voltage to the headlights, but it didn't help much. Best fix was the Hylux or Morimoto HID conversions back then. There may be other options now. You might check out the "pinned" Headlights topic/link

My first indication that something was not right, was about 4 times before it completely failed, when I went to heavily accelerate and pass someone on the highway, when it downshifted it did like a double backfire, stumbled, then regained itself and went. The last time when it finally failed it did the double backfire sound, then I heard a bang, the engine started vibrating and lost power and the check engine light as well as traction control light came on. Additionally the engine made a rapping/tapping sound the rest of the way to work. The guy working on it said the AFM lifter failed internally but my cam looked okay visually. Going with the full DOD delete cam and lifter swap now. Hopefully it never becomes an issue again !

I'm at 138K and on the 2nd failure of the #7 AFM lifter. First time was at 55K, about 4 years ago, when GM paid for it. This time is on my dime. Not having the dealership do it this time, it's at a shop with plans to do a full DOD delete cam and lifter job as long as there is no other damage found. It really is aggravating buying a vehicle new, doing all the right maintenance and still having these kind of breakdowns !

Here we go again ! 4 years and 85,000 miles ago, I had the #7 lifter fail and had it covered under the power-train warranty. Now I'm at 139,000 and it looks like I have another #7 AFM lifter failure. But get this, I tuned off the AFM at 99K miles, and it still failed !!! For a couple weeks before, I noticed that when on the highway, if I stepped on it hard and it downshifted, it would do a double backfire sound, kind of a stutter, then finally regain itself and go. I had gotten gas at a station I've never used before and thought it was bad gas. I added a bottle of fuel treatment and finally refueled. Next day, I'm on the highway and go to pass a semi, and when it downshifted, it did the double backfire thing again, but this time I hear a sort of bang in the engine, then it stuttered, then the check engine light comes on, along with traction control light, engine vibration and reduced power. I limped it into work and checked the codes and have P0300 , P0307 & P0324 . Luckily I live down the street from the guys that own Prevatt Automotive Tuning here in Tulsa. Initial diagnosis is a dead #7 AFM lifter and hopefully nothing worse. Now just waiting for my turn in their shop. I'll update in a week or so once they open it up......

Did you ever get this resolved ? My 2014 acted up about the same, similar codes, vibration, reduced power, etc. Mine had the P0324 & P0307 (#7 Cylinder misfire code) I'm at 138,000 miles. I checked what I could and swapped coils, plugs and wires, then finally pulled the drivers valve cover. Had the one "dead" valve spring on #7 cylinder which is one of the AFM cylinders. The dealership is not the place to go for this job if you are off warranty. I have the truck sitting at the shop now waiting to get in for a full DOD-Delete cam and lifter swap. I hate all this expensive and unreliable crap they put in the engines now !