Dnt

Quad tips look great I will have that added to my 19+ truck before I pick it up at the dealer (if it is available for a 6.2) when I trade up in a year or so. If you do not have a tip that says Borla how would be people identify the exhaust system? crawl under your truck? Hmm this pic is upside down so try not to get too dizzy, you might fall down and be looking under a truck or something LOL!

Man it is disappointing to hear that the 19's are STILL having this problem. I have had (3) new GM 1500 truck's a 14 - 5.3 6spd / 16 - 6.2 8 spd / 17 - 6.2 8 spd and they all had the harsh slow speed downshift to some degree with the 14 being the worst. This 18 seems to be "harsh downshift at slow speed" FREE so far, but it only has 6k miles.

Sounds like the grandkids dropped something in the vent. (nasty little buggers I do not let them in my truck) Might be a good opportunity to purchase a borescope they make them now that connect right up to your smartphone for CHEAP Check this one out https://www.amazon.com/DEPSTECH-Semi-Rigid-Inspection-Megapixels-Waterproof/dp/B06WRNGYXY/ref=pd_lpo_vtph_469_lp_t_3/144-4291733-7538323?_encoding=UTF8&psc=1&refRID=K4G9036R4HMB55X0EMGV Might find like a million dollar rare coin in there Hahahahaha

Same here Jimmy I had a 14 and then went with a 16 and had the shock. Got used to it on the 17 and now I am just numb to it I guess on the 18 as it no longer bothers me EXCEPT WHEN I READ THIS THREAD ABOUT IT Man now I am upset "thanks GM" ..............................................gotta go see ya bye

2009 Chevy Tahoe with 3.5" lift 10 x 20 wheels with Nitto grapplers. I get the stabiltrac flashing light on both right and left hard turns. This is of course older technology, it does not seem to grab the brakes or do anything noticeable or dangerous, just an annoying flashing light at times. It might be something else but I think the lift is what is causing it? I am taking it back to the place that did the lift to check everything out if they come up with something I will let you guys know. I realize this is not a late model nor an actual Sierra or Silvy but might find out something useful.......it does seem to be a fairly common problem around the internet. Check out this cool TaHOe pic and yes I know it is a Hybrid and that a lift and big wheels and big ole heavy knobby tires wheels defeats the Hybrid purpose. I bought it like this LOL.

People think that automotive paint shops always run smoothly but the fact is that there are constant problems with booth humidity conditions/silicone contamination/Paint or Primer cure issues with Ovens going down. It is a miracle that more vehicles do not have paint falling off and if you think GM is going to pull a entire shifts vehicles off and repaint them you have lost your mind LOL. Just the luck of the draw and no way to trace what the issue was when your truck was painted but something obviously happened that affected the paint quality. If some others out there are really seeing this same issue with this color paint they need to all get together and compare Build Dates you will probably see an exact match THEN GM might listen to your guys as a group and issue a repair order out to your dealer. Good Luck fellas.

I would start with a new serpentine belt. While you have the belt off turn all the accessory pulleys and tension-er by hand look for a wobble and feel for any play/roughness or a squeak as it turns. i suspect the water pump but could be about anything.

Grumpster, have you thought about integrating an electric drive motor to maybe boost your mileage? Maybe the MPG could be measured in triple digits instead of double digits? This behemoth that I bought only gets 20.9 average over 2500 miles so far, I was expecting much closer to 30. If I mount a Bird Scooter to the back trailer hitch would it be able to push the truck along do you think?

If I had listened to the negatives on this thread then I would have missed out on a great bed cover. I bought the FAC G4 Elite from the factory website for my 2017 CC Std bed Denali Ultimate (about this time last year) and just moved it to my new 2018 CC Std bed Denali Ultimate. It is a great cover, still looks and functions just like the day that I installed it. I did not use the FAC tool box I incorporated a Bakbox into the front of the bed and it is perfect for me as it is smaller and I can open the front leaf of the FAC bed cover and still reach items laying on the truck bed at the front. This where the TriMode steps work out perfectly. I have NEVER deal-ed with customer service as I have never had a problem, that might be a legit item to research more on.

I have a Theory on these mysterious engine problems. My 2017 developed a serious HPFP leak, it was pouring gasoline down into the oil crankcase. It was a least 2 quarts over full on the oil dipstick with pure gasoline. Dealer replaced the HPFP under warranty but it was a very noisy engine after this incident. Now combine this with the extended oil change intervals and we have a recipe for disaster. I think there is probably a percentage (hopefully a small percentage?) of these engines with a HPFP gasoline leak and after these engines run with gasoline diluted oil washing all the bearing and interior surfaces the engines are simply disintegrating from the inside out. The current HPFP is a flawed design and should not be mounted on top of the engine where this could happen! There is a thread on here somewhere named "Check Your Oil Level" or something similar, it has some good info. The dealership service department clams up after this happens and they have obviously received some coaching to mark on the repair ticket NO ENGINE DAMAGE caught in time, no matter what evidence is presented by the poor ole screwed customer. Huge liability for GM and the GM leadership will take this secret to their graves if they can get away with it. I NOW CHECK MY OIL LEVEL AT EVERY FILL UP ON THIS NEW 2018, IF I SEE THE OIL LEVEL EVEN SLIGHTLY CREEPING UP, IT WILL GO STRAIGHT TO THE DEALERSHIP IMMEDIATELY FOR A HPFP SWAP. Hopefully a redesign of the HPFP location came with the 2019 remodel?

A lot of what is going to happen is going to be dependent upon the dealership service department. Most are very happy to just write on a service ticket "Operating as Designed" and tell you to go pound sand. I was told by a service employee that this is due to the fact that they have to diagnose the problem and if it is a hard to pinpoint type problem most will ignore you, and hope that you disappear. Apparently the diagnostic time is only paid for by GM for a short few minutes after that the meter is running on the dealerships dime. I would hazard a guess that the motor/transmission mounts are just the symptom and not the base of your problem. If you wish to keep the vehicle I would gather all information together (IN DETAIL) and try a different dealership service department. me myself, I would probably (actually just did) trade my problem vehicle but I understand that some folks do not wish to take a financial loss. I did not want to take the hit either but I calculated out that it was going to cost a Bunch of my time and the issue was probably going to take some of My Joy so BAM 7k thrown down the toilet just to trade up a year. Thanks GM you bunch of %&@'s LOL I guess the question is how much is your time worth? My New truck is cute though...............

If you drive half way decent any modern truck will get 20+ mpg unless it has a mechanical problem. Most people are on the gas and then right back on the brake and then expect good MPG LOL it will never happen unless you pay attention to your driving and change your bad driving habits. Looks like around 21 mpg on this 18 after 1000 miles which is just what i would expect.

OP mentioned a FORD 250. We have a fleet of 17's and 18 at work and one of the 4X4 trucks with fairly low mileage develop the DEATH WOBBLE. Will scare the beejesus out of you when it does it LOL. Seems to be a shock absorber on the steering linakge that goes bad from what I hear. So GM is not the only one suffering front end problems on the HD trucks

Found a great deal on the bakbox and it is a bit smaller than the personal caddy allowing you to reach down past it when the front cover is opened. It did take a bit of engineering to make it work but I had some extra brackets left over from a Peragon cover install on my 2016 plus I had to trim the end of the bak box a little to clear the cover latches. Probably not something that most people would want to tackle.

I had the GM Borla exhaust (touring) on my 16 6.2 and liked it so i put it on this new 2018 6.2 It is a fairly subdued exhaust note, just right for me, and just right I think for my neighbors too. Note: If I had a neighbor with loud exhaust that woke me up early in the morning I would probably stuff some potatoes in his exhaust pipe Hahahahahaha

I just added the snake oil (lucas transmission fix) into the transmission on my 18 year old kid hauler Windstar van. It has developed a torque converter seal leak. Not worth pulling the transmission to fix the seal and the lucas did seem to actually slow it down a little (or is it wishful thinking?). I cannot tell any difference in the shifts at all though. As far as pouring snake oil in a new +64k MSRP truck naw I will pass on that LOL. To each his own I guess.

Yes I agree a lot of the decision to do a warranty repair is initiated by your dealerships service department. If you have a fat lazy service guy that hates his job and just wants to put his hours in without any extra effort like the guys at Beaman you will get told to pound sand on any warranty repairs. Forget any rust repair or other gray area it will not happen there you have to go with a quality / customer oriented dealership service department like Wilson County GMC. Just makes me upset that I have to drive 50 miles round-trip just to get a GM service department that does not have their head up their arse.

I like the idea of letting the dealership repair it. OP thanks for posting the info, if I spot some rust it looks like it will be taken care of, and that is good news. Only problem is my closest dealership is Beaman GMC in downtown Nashville and from past experience with them they will probably write on my repair ticket "Operating as designed No repairs Done" I will have to drive 25 miles to get decent service at Wilson county motors. Yes I am dogging Beaman Service department BECAUSE THEY DESERVE IT AND HAVE EARNED IT. Note: Beaman has an excellent paint department (different building and different management) it is just the service department that is weak. Beaman if you read this and the many other reviews that I have put out on your poor service department please make some management changes and get yourself back to doing good customer service. I would like to utilize it when needed.

Got the 2018 Denali Ultimate last Friday. So far the shifts are crisp and no harshness but I am only at 600 miles. Liking this GM Borla exhaust that I had put on this one before i picked it at the dealer, just has a deep throaty sound. Makes any distress over a harsh downshift insignificant if it happens my plan is to get on the gas Hahahaha

Just moved my FoldACover and BakBox tool box from my 2017 to my new 2018. Works great for me with the trifold steps the FoldACover front 1/4 panel flips back and reveals the BakBox underneath, you can easily reach everything in the tool box by stepping up onto the extended trifold step.

Would love to know this myself. i typically trade every year and I am looking at maybe a Black truck this time around. This 2017 is pretty good but still has an occasional episode where it has a harsh downshift.......

Way over your budget but I put on a FoldACover and worked in a BakBox underneath on a 17 Ultimate. Works great with the trimode steps.

I just had what is apparently a rare occurrence on a 17 6.2 engine. the internal diaphragm inside the HPFP was leaking gas into the crankcase and mixing with engine oil. I noticed the oil level going up and was getting a strong gasoline smell when I rubbed the oil between my fingers on the oil dipstick. You guys need to be very diligent about checking the oil level at each fuel up. It is a rare occurrence but if you run it very long like that it will destroy your engine. Catch it early and you might be OK I am currently campaigning GM for a free extended powertrain warranty on mine due to not knowing the extent of the damage but knowing that there probably is some.

I bought the locking cover from the TrunkMonkey site https://www.trunkmonkeyparts.com/ was about 15 bones. I like it and I will keep using it. It does take a bit of force to pull it off, so heads up if you have low hand strength (desk job folks) it might be too much for you to handle and you should probably look at alternatives.

I had the high chrome Cold Air Inductions intake on my 2016 6.2 I liked the look and the sound. I am contemplating installing it on my 17 I just have not gotten around to it yet. Lost one of the high chrome fasteners for the air flow sensor when I took it off the 16. I contacted Cold Air Inductions and they sent me a set for free so I would rate their customer service as good. Dang thing is pricey though. Shoot now that I have thought about it I might just pop that puppy on there first thing in the morning no need for it to just be setting on the shelf in my garage! VROOOMMM