2017 1500 High Country

[aotte1]

Purchased a 2017 1500 High Country with 5.3 engine, crew cab, short bed.
Initial reaction is not good, several small problems now at 1800 miles, along with not liking drive train. Not sure what is going on with engine and trans. Engine seams to not have power, and towing 5K lbs. is a real struggle. No way it has HP and torque they say. Will hardly accelerate, when you use half to three quarter throttle, engine rpm goes to 5000, trans seems to have big time converter slippage as truck only accelerates maybe a few additional MPH when going 45 MPH. This new trans/converter seams to not function well. It needs lots of RPMs to accelerate from a stop, again converter seams to slip a lot. Needs 2000 RPMs from a stop vs. my 2010 5.3/6 speed auto needing only 1200 to 1300 RPMs, for same rate of acceleration. The trans also makes a very HARD clunk when shifting sometimes, at light loads/acceleration.
Small problems; 1) complete windshield washer system needed replaced, 2). Outside Temperature reading not working, 3). Lane change alert system stopped working, 4). Bed lights not working, and 5). Rear back up monitor in cab is very faint, hard to see.

Very disappointed in this truck, would not buy again, overall seams extremely cheap.

Recommendation, do not buy the 5.3 engine, they have ruined it, maybe 6.2 is better? It is possible the 8 speed trans is pure junk, vs engine.

Have always been Chevrolet person, first was a 68' Camaro SS/RS 396, followed
by at least 30 other new GM vehicles. Current vehicles are 2010 1/2 ton Silverado - great truck, 2014 GMC Acadia - nice vehicle, 2012 Corvette GS-CE outstanding vehicle!! And collection of 65 and 66' trucks.

Friend has similar 2017 LTZ and it has ALL the same engine/trans problems.
Know vehicles a little as race NHRA "C" stock automatic, 70' GS 455 stage 1.

[4x4k30]

I would take it back to the dealership if they check it and say they cant find any problems I would take it a mechanic that you can trust and have them check it out or find another dealership I know how it is with warranty work it sits there until they want to get to it the other big paying jobs come first. it does sound like you have a lemon the truck should do better than your 2010 does good luck

[aotte1]

4x4 thanks for reply.

Also forgot to mention that both front doors are rusting after owning six weeks, in sunny Kentucky. No winter, no salt. Will post pictures soon. The rust is the seam where the two door half are welded. The seam sealer used, has cracked and let water. It is rusting uncoated metal. The rust is coming out the crack and staining the door jam paint. Thought GM was using metal body panels that have a rust protective coating, befor being painted. Guess not anymore, new six week old track and door jam is rusting. Again this is summer/fall with only rain?

[aotte1]

Door jam photos, at 6 weeks.

[4x4k30]

dang they must have sold you a new truck that they ran the water spray test on to for too long and that looks bad I cant believe that gmc trucks are getting that bad my 77 gmc is 40 years old and does not have any problems like your does I would check on the lemon law in your state and demand your money back .

[aotte1]

Discussed these issues with very knowledgeable person on GM trucks, and he has same option on this 2017 power train. He has driven the 2017.
I am now hoping, GM will write new control program for trans and engine.

A good thing is it can gets crazy good mileage on the highway, high for Z71 is 26.2mpg and High Country is 25.2 mpg. Even at plus 70 going up and down hills with load in bed 21mpg. Going up mountain On I64 in West Virginia the Z71with around 1500 lbs. in truck it got around 19 mpg. Their are several good things on these trucks, however, powertrain is not one of them, except for mpg on highway.

The bad thing is not knowing which gear it wants to be in, loud clunking sometime when it shifts, converter slippage on starting from stop and down shifting at WOT or 3/4.
The truck does not accelerate well under WOT or 3/4. Has very little towing power.

The rated HP/Torque is not showing up, for some reason. With this much SAE rated HP it should accelerate pretty quick, it does not. With E85 fuel this is supposed to make 395 to 400 HP per GM Powertrain Division documents on the web.

Option, in may ways, for very technical/knowledgeable person, it is not fun to drive.

[Prong]

If you have the 8 speed trans, there's a programming update for that to reduce the bang shifts. I believe the tsb# is 16-na-411. I had it done to my 15 and it corrected 98% of the troubles.

[Hart_Rod]

Originally Posted by Prong

If you have the 8 speed trans, there's a programming update for that to reduce the bang shifts. I believe the tsb# is 16-na-411. I had it done to my 15 and it corrected 98% of the troubles.

Is that for all years?

[LEEVON]

The 8-speed is a different animal, I hope they can help you. Be glad you didn't buy the factory vibration that GM has no clue how to fix. My 17 Sierra has been somewhat disappointing and is about to get the boot before 3,000 miles. I can't stand the vibration and there is no fix in sight. I also have a bad shudder on deceleration and the cabin is so cramped. Also my seat is already wrinkling on the outer edge and it's not comfortable, I feel like I'm sitting on a fat wallet on each butt cheek. And I'm sitting completely upright, it's got less room than any regular cab I've owned from the 40's and up.

I am very jealous of your mileage, I'm at 15.6 combined highway/city and it's a regular cab 2wd 5.3/6 speed. It should do much better, otherwise why do I have to have all of this direct injection? Make sure you're getting all of this documented!

[Prong]

If you google that GM TSB#, it gives a list of what it covers. I believe there's also a reference in the document to other years that the update may apply.