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About 14SLE

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  • Name
    Tom C
  • Location
    Southern Ohio
  • Gender
  • Drives
    2014 GMC Sierra SLE Crew Cab
  1. Thanks for the information about the TSB. Unfortunately, I have the six speed transmission and I had it flushed at about 50K miles. I did not notice any difference in the behavior. I have been privately told by service folks to be glad that I have the six speed instead of the eight speed transmission. The weather is staying warmer now, so the problem is much less noticeable overall. What really puzzles me is why the truck was really good for the first 10K miles (more or less). I bought it in October of 2014, so my first few months of owning it took me into the colder weather months. Does GM dial up the aggressiveness of the fuel economy measures over time so you are stuck with the truck by the time they fully engage or is the truck just wearing in as time goes by? If the truck had behaved like it does now when I test drove it, I would never have purchased it. I would be overjoyed to have the truck drive the way it did when I first bought it.
  2. I thought the Tech2 was phased out for new cars years ago, but I wasn't sure. The dealership says there are no codes present, so I assume they are using the correct software (may be a big assumption on my part). Can you please tell me more about the TSB flush? If you have a TSB number or title, I will look it up and try to get them to do it the next time I get the oil changed.
  3. I'm not sure it is misfiring--it's just a clunky shift between V8 and V4 mode. The temperature has a lot to do with the behavior--it was in the 80s last week and the V8 to V4 transition was almost seamless (one minor jerk/clunk on the way home). When it is colder, it jerks, clunks, or shudders on the V8 to V4 transition probably half of the time. I mention this to the dealer every 5K miles when it goes in for an oil change--they try to pull the codes and see nothing. The V4 to V8 transition is smooth. Infrequently, when going V8 to V4, there is a kind of resonant metallic sounding vibration, as if a motor mount were failing. There is never any problem when going V4 to V8 other than the PEV squeak that I have been unable to remedy. Thanks for the replies--I'm just trying to determine if there is something else wrong with my particular truck while I still have the extended warranty. One fellow here at work with a 2015 model has some of my problems and a lady with a 2017 said she never experienced any of the issues. I'm not sure if they fixed the system over time or if my truck has issues.
  4. Thanks for the advice. Regarding the vxdiag device, that's an awesome price for an MDI substitute! However, I have access to a Neo Fire at work that also performs the J2534 pass-thru for diagnostics (SPS/Tech2WIN). The truck is not showing any codes at this time and the dealer tells me that SPS has no way to force a re-learn. I haven't played around with the dealer tools, but I seem to recall reading elsewhere that there is not a way to clear learned behavior. I was hoping someone on here could tell me if that is true or not. Regarding the camshaft/lifter issue, how does one know if a collapsible lifter is failing? Are there any other signs beyond the periodic stumbling I am seeing? The AFM works flawlessly at times and jerks badly at others--it all depends upon the speed, temperature, and engine load. Since I have plenty of warranty left, I have no problem taking it to another dealer, but I want to make sure I understand the symptoms properly so they don't blow me off, too. The slamming is definitely worse in the winter (as I said, below about 45 degrees), which is when I drive the truck the most. I have old cars that I drive during good weather. When I get back into the truck after driving the old cars, it makes me want to move somewhere warm where I could drive the old cars all the time. Thanks again for the replies!
  5. This may be a rather strange question, but is it possible to reset the learned driving habits? My 2014 GMC Sierra 1500 SLE 4x4 crew cab drove great for the the first year (new to about 10,000 miles). The truck was very responsive and the AFM was not bad then--it only kicked in at about 45 mph or greater and it was not objectionable. After about a year, the AFM started engaging much more aggressively and at lower speeds--the truck would periodically jerk violently when it entered V4 mode. It began trying hard to avoid downshifting, so there is absolutely no power when you turn corners or start up a hill unless you really shove down on the gas pedal. I distinctly remember a coworker saying, "What's wrong with this thing?!?" soon after the clunking and other stuff started. The dealer said it was learning my driving habits and everything was normal. Now, I have 57k miles on the truck and I really do not enjoy driving it anymore. I have about a 25 mile commute with long stretches of 35 mph speed zones. If I don't drive in M5 or activate the Range device, the truck repeatedly goes "CLUNK, lug, SQUEAK!" as the AFM engages, the truck lugs along for a bit, and goes back to V8 mode (with passive exhaust valve squeak, of course). I have noticed the clunking is much worse when the outside temperature is below about 45 degrees. The dealership says I am stuck with this behavior because it has adapted to my low-speed stretches and there is nothing I can do about it. They say most of their similar complaints come from people who drive at lower speeds. The truck has only been maintained at the dealership--I got tired of them saying I was not maintaining my last truck properly (Mobil-1 changes at 4-5k miles or 45% oil monitor remaining, coolant and transmission flushes at 30-35k, and all fluids replaced at 50k miles, mind you). I have had them do far more maintenance than recommended and I don't hesitate to throw this fact back in their face when they start to say I have done something wrong to cause the bad behavior (they said going too long between oil changes probably caused it until I told them to check their records). They tried pulling the battery and it didn't help anything. I would love to have my truck drive the way it did when it was new. I know I could get a tune, but I have an 84 month, 84K mile warranty and I don't want to risk having too many increments of the flash counter. My dealer says to get a tune when the warranty expires, but I doubt I will keep the truck that long--I honestly don't have much faith that the drive train will hold together. The constant "clunk-lug-squeak!" reminds me of the clown cars you see at a circus. Does anyone know of a way to reset the learned behavior or do I have to live with it until I get rid of the truck? I can get access to SPS if there is a way to resolve this via the dealership tools. Any help would certainly be appreciated!

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