Stex

Only miles will tell if DFM is a problem. Hope they fixed those lifters. And the DFM does have as much if not more than AFM going on mechanically. And the software and number/swiftness of decisions the ECM makes ....Tech article: As you probably are aware, AFM was a relatively simple system which converts a V8 engine into a four-cylinder (operationally) by deactivating four cylinders. DFM expands on this idea by installing the AFM style, spring-loaded lifters in all 16 positions so that all eight cylinders (instead of only four) can now be selectively deactivated.......Mechanically, DFM is just an extension of the earlier AFM system. They have levers in the lifter deactivation chain. As to running smooth and cannot tell DFM is there, see this: more mechanical , These new DFM-equipped trucks and SUV’s will also be upgraded with what GM calls a “centrifugal pendulum absorber” in the torque converter. Essentially, this is similar to a dual mass flywheel for a manual transmission. This pendulum absorber employs coil springs mounted to a plate splined to the input shaft of the torque converter. This pendulum device will isolate noise and vibration between the engine and the transmission. When cylinders are deactivated, the number of crankshaft rotation increases between firing pulses. A V8 firing all 8 cylinders sees 90 degrees between combustion events, while a 4 cylinder engine lengthens this to 180 degrees. That inherently less smooth operation requires additional NVH dampening. https://www.enginelabs.com/engine-tech/gm-escalates-cylinder-deactivation-with-dynamic-fuel-management/

Oil soaked Piston rings on my 09 at 50,000. CC on now but too late. Has GM improved on this? I don't trust them on that or AFM/DFM. GM runs a CC set up on the Camaro now. Up to each GM owner but I would run one on anything GM or other makes....

Just not good. GM should make everyone whole on this leaking issue. A Cover buy back seems in order. Not even close to the look, but I went with a one piece undercover just to assure a weather tight fit. They Even have dust kits to keep dust out of the bed. Easy To remove. light and one can stand on the unpainted ones. https://undercoverinfo.com/undercover-classic

Thank you. And Nice truck! GM Finally has some nicer wheels for the 1500s. The GMCs where really strange when I bought my GMC. Chrome clad wheels back then. I have been running 18s, due to pasture use. Will look at 20s this time.

Nice. Like the wheels! Can you tell me what wheels those are and size? They do not look OEM?

Noticed the same thing for the last two years on test drives. Dealer needs to have some returns and write ups on this. Really doubt GM will move on the issue. But they have to have many dealer complaints filed to even be on their radar. Doubt the dealer will do anything. Not much they can do. This will be a job for a quality auto upholstery shop. Because of the seats and trans, I was so go on the 2017& 2018, now '19s. The seats where just hard and uncomfortable after 15 mins. I would spend the bucks to have it fixed. My '09 SLT buckets are great. Wife loves them. The new ones, no. Also noticed that on the newer trucks they removed the small amount of padding on the outside frame, where the seat back and bottom meet. Not a big deal, Unless one does not use steps. I'm 6'3" and just step in/out of the truck. Going out the unpadded frame rubs harshly on upper leg bone. If I get one I will have to have a good upholster address the issue and the hard seat. Lucky we have several in the big town of SA.

with AFM or DFM one has lifters continually pumping up/or collapsing. On the DFM the mechanics are more complex and a bigger chance for failure. Most folks cut off AFM/DFM to cut down on all this mechanical wear of on/off lifters etc...On the AFM, I read that GM said the gas savings from AFM was less than a mile per gallon. IF one drives in traffic with traffic lights etc... on a regular basis, the stop/start will/should save one more gas. My AFM is off. No stop/start yet but when I do get one, it will be disabled too. I agree, Just nice to have the option.

Did yall watch the 14 minute engine vid walk through? If that does not strike one as complex, with a lot of valves and sensors and water flow here and there based on this and that, I do not know what will. As one that had the early model 5.3 with the new AFM issues, the 6.2 looks like the way to go for a few years at least. Edit: 6.2, even with the new DFM, still seems like a better choice. At least there will be a DFM deletion kit soon, should it give one issues after warranty.

Yep, agree. Seems way too complex. It has a lot of new this and that to pass EPA and get good mileage. Not a first year engine buy for sure. IF one gets one, one better get 100,000 mile power train wty. . 6.2 seems a better choice right now. .

Yes. My friends trail boss bed is a stretch for me and I'm 6'3" with long arms. He is normal height of about 5'9" and works wi see the bed floor with the gate up. I think he can just reach the floor. I can get in and out fine with out the use of steps. Him no. They do seem high, He says that even the non trail boss trucks are about 2 inches higher than the previous models????? I have not verified that . Yes they do seem tall even at 6'3". But I like it I think?

I forgot to add to my the DLC not that accurate for MPG post, that I always buy a truck and worry about MPG. Driving a brick down the road has to mean one is not or should not be concerned about MPG. Per my Dad, (RIP), How much rain did you get and MPG answers always require some skepticism. Computer or manual....

I am amazed at the number of folks that do not realize the dash computation is not that accurate. One needs to fill up at the same pump and run a tank or half and calculate it manually. Camaro forums have been all over this. One can also never reset the overall MPG and run say a year and get a better idea of MPG.

IF GM pulls up short on you, it might be time to seek a quality independent body shop. They deal with these issues daily....

I would try to meet them at 1.5k for new or ask for a crate motor. If repair is done, then the 1.5k. They can resell " their" well repaired truck. The 3k sounds like they are trying to cover their butts on the resale of your truck. Maybe worth $ to have a lawyer look at the deal. IF they drove your truck with low oil and now trying to give you their repair of their screw up.

Hope it continues to be all good. May I ask how many miles on the ride? My A6 is also a pain to drive. So bad I had it tuned.