Hello From a New Sierra Owner plus two questions

stever1986 · June 9, 2014

Hey Guys,

Just join the forum and also just bought a new 2014 Sierra Dbl Cab SLE in Sonoma Red. Beautiful Truck and i just want to keep driving it. Traded in my 2007 Chevy Impala SS for this and although that chevy had some power, this truck not far from it. With employee discount, trade in, and 3250 cash back, I couldnt let this truck not be in my hands.

I have had the truck for a week. Bought it with 4 miles on it and it now has 400. So far I have done the Retrofit Source HID Kit, Magnaflow catback, and tinted the front side windows to match the back.

My truck was a March 2014 Build date. I have researched all the issues people have been complaining about on this forum. So far I have experience none. My radio reception is perfect, in fact better than my chevy impala was. The channels are clear and I live an hour from Philly where the stations are located. No issues with the seats. No vibrations (I have the 20 Inch Rims with Continental Tires. No Goodyears!) The frame has no rust although I did see an older truck there with rust issues. However I did notice two things which I have questions about

1. The 6 speed transmission must take some time to get use to. This is my first 6 speed auto tranny and it does good but sometime it seems to want to shift where ever it wants. Might be normal? Also the AFM. For example I can be doing 60 on a highway downhill with foot off pedal and sometimes it will stay in V8 while another hill it will go into v4. I also did have what someone did describe as the being rear ended feel where I was slowing down in traffic while in V4 mode and hit the gas and it seemed to shift hard into a lower gear but never did it again. Again I bought the truck with 4 miles on it and took it on a 4 hour round trip to the poconos this weekend. I am guessing it is still learning my driving? Has there been a recent TCM or PCM update?

2. When the truck is idle, does your truck sound like there is a noisy lifter or something making a similar tapping noise? It not loud or anything just you can hear it. Once you get the rpms above 1000, it gone, only does it when it idle at 500-800. The motor so quiet at that range.

Other than those two things, simply love the truck and happy to be apart of this forum.

KeukaZ71 · June 9, 2014

I noticed the same issues you have. I only had my truck for two weeks now. Same noises and same behavior

2016 Sierra Owner · June 9, 2014

Welcome to the forum and GMC ownership. I have seen the same problem with AFM as you describe. Going down some hills it shifts to V4 on others it does not. I did find one day that if you give the fuel just slight pressure going down the hills it does this on. It will switch to V4 and stay there. I'm not sure why but, it has worked for me so far. As for the ticking at idle. My truck does this and it is from the direct injection these engines now use. It sounds really bad when in a drive thru with the window down.

stever1986 · June 9, 2014

Thanks for the welcome. So i guess the question for the tech gurus here, has there been a TCM update to help smooth and solve the V4 down hill issue. My Chevy Impala SS also had AFM and it seemed to work better but figured maybe the truck still learning.

As for the noise at idle. It good to know it is normal but yea the sound make other think something is knocking. 3 of my friend with me already said, what is that sound? Now I know what to tell them..

GMC-AT · June 9, 2014

the trans just sucks... but it does get better after 5,000 miles or so...

thewhitestallion · June 9, 2014

the trans just sucks... but it does get better after 5,000 miles or so...

its not so much the trans as it is the pcm. but im sure that is what you meant I I agree with you completely!

TxTruckMan · June 10, 2014

1. I read someplace that sometimes the engine will shut off fuel completely while coasting to conserve fuel. This is likely what you are feeling. That will slow you down faster than if the engine was idling. Then when you step on the gas it starts burning fuel again. Basically a Start-Stop system when coasting instead of stopped.

2. Direct injection engines sound this way.

nrbrandt · June 10, 2014

I think the engine noise wouldn't be noticeable if they hadn't made the exhaust so quiet. Mine is a really quiet truck at least.

fondupot · June 10, 2014

1. Yea the trans takes some time to "learn" your driving style so to stay. The first couple thousand miles ~1000-2000 are a bit quirky, but then it gets dialed in nicely. I have 8400 miles and I think its great.

And AFM is all torque based. I have found the same scenario rolling down a hill and it stays in V8. its because the trans is using the torque to keep the speed constant at 60 mph instead of free rolling and picking up speed. The AFM takes a bit of time to adapt to, but once you are familiar with the characteristics, it will become a lot better. I hardly ever notice it now.

2. The lifter tick you are hearing is actually a characteristic of Direct Injection. Totally normal the fuel injectors are very high PSI and they are loud.

Congrats on the truck! Welcome to the forums.

JT-IN-BAKO-CA · June 10, 2014

can you provide me with a little more information with what your HID kit did? are there models that don't come with HID that I am not aware of?

stever1986 · June 10, 2014

every truck comes with halogen bulbs. In my opinion, they suck. I bought an HID kit to give me brighter headlights

scott19677 · June 11, 2014

1. Yea the trans takes some time to "learn" your driving style so to stay. The first couple thousand miles ~1000-2000 are a bit quirky, but then it gets dialed in nicely. I have 8400 miles and I think its great.

And AFM is all torque based. I have found the same scenario rolling down a hill and it stays in V8. its because the trans is using the torque to keep the speed constant at 60 mph instead of free rolling and picking up speed. The AFM takes a bit of time to adapt to, but once you are familiar with the characteristics, it will become a lot better. I hardly ever notice it now.

2. The lifter tick you are hearing is actually a characteristic of Direct Injection. Totally normal the fuel injectors are very high PSI and they are loud.

Congrats on the truck! Welcome to the forums.

Fondupot is correct. The ticking is just the D.I. but still drives you nuts at the drive thru window. As for the AFM some are worse than others. I still can not get used to it. I have another post about how to drive in "MANUAL" mode .You should try it. When say for instance when in in M5 the trans will run thru all gears up to fifth .but the best part is NO V4. See, Manual mode is not really Manual mode as compared to previous years. Just pull it into M1, 3 or 4 clicks on the shifter and happy motoring. If you have questions just PM me and I will explain it a little better.

JT-IN-BAKO-CA · June 11, 2014

every truck comes with halogen bulbs. In my opinion, they suck. I bought an HID kit to give me brighter headlights

My SLT came with HID's

I just read the brochure again and going from sle to slt is when they go to a projector

TxTruckMan · June 11, 2014

My SLT came with HID's

I just read the brochure again and going from sle to slt is when they go to a projector

Projectors and HIDs are not the same. We have Halogen projectors, not HID projectors. All Sierras come with the projectors. The SLTs and above get the LED DRLs while the lower models get none.

JT-IN-BAKO-CA · June 11, 2014

Projectors and HIDs are not the same. We have Halogen projectors, not HID projectors. All Sierras come with the projectors. The SLTs and above get the LED DRLs while the lower models get none.

o okay thanks for the clarification.

It would be nice to see a before and after once you upgrade to HID. also is there a of the shelf kit for our truck?