New Silverado No throttle responce, bad gas milage, clunky transmissio

SLOW3R · November 27, 2014

Bought a new 2014 Silverado last month, double cab, z71 5.3. Been a gm truck owner since I was 16.

I have 1500 miles on it now. I did test drive a bit, but didn't realize these issues at the time. Heres my issues with it.

It is completely gutless, throttle response is non existent, unless you really get on it, and then its too much. Feels like im pulling a boat anchor everywhere I go.

Crappy mileage, Best mileage I have gotten was 17.4 mpg on a tank, and that was 90% highway and interstate. Hand calculated and on the dash. Yes its a truck I didnt buy it for fuel mileage, but when they advertise something it should at least get close to that. I do realize its winter blend fuel right now. Im averaging 13mpg right now.

My 05 I had 8 years got 17.5 Every tank with mixed driving!!!

Lastly, is the clunky transmission and always seems to be in the wrong gear, lugs, Hard 1-2 and 2-1 shifts.

Do these seem like computer related issues? Im bummed I cant even enjoy my new truck. Any input or similar issues?

bdbake01 · November 27, 2014

The throttle response will dramatically improve. When I first got my truck, I seriously thought something was wrong with it. But around 2k, became night and day.

Transmission will get better as well. It'll never be butter smooth, it's just a GM 6. But it'll get better. You'll always be able to find weird, clunky spots in it.

Mileage, I dunno, but give it a while and a few tanks before you pass judgement. I got about 15 on the dealership fill of what must have been 75 octane.

Silverado Steve · November 27, 2014

Give it time to break in. Mine calmed down around 3K

SLOW3R · November 28, 2014

Was it noticeably different all of the sudden for you two?

SLOW3R · November 28, 2014

And one more thing I forgot to mention, I can feel it switch from v8 to 4cyl mode. Is that normal or should it be un-noticable?

Stevens03 · November 28, 2014

What gears does it have?

SLOW3R · November 28, 2014

3.42

Silverado Steve · November 28, 2014

Mine was subtle. Once the ECM learns your driving style, the throttle will open up a little. However, due to GM gearing our trucks for mpg, they arent screamers off the line even after 3K on the odometer.

SLOW3R · November 28, 2014

I realize it wont be a screamer off the line. I do not drive like that. I would just like to leave a stoplight with out feeling like I am tied to the pole.

bdbake01 · November 28, 2014

Subtle, but noticeable. It really wasn't a 3k mile gradual change though. More like the same 'ol for 2,500 then a change over the next 500.

f8l vnm · November 28, 2014

Same issues here. I still have not figured out if it's the pos transmission or the pos tune the transmission comes with it.

The clunking, the bucking is super annoying. Truck feels confused most of the time as to weather it wants to shift or rev higher. Again I've said it many time, the drivability is a joke on my new 6.2. Off course gm dealership with the same ole bs , telling me it drives normal.

After 5 times in the dealership in less then 2 months I've kind of given up on the morons at the dealership. This truck is a lease and probably the best decision I made not to purchase it.

It's a nice truck but the quality in which is was put together is shit but then again Im the fool for thinking gm had changed.

BigBadSierra · November 28, 2014

I run 91 in mine no throttle response issues.

I do have times Stability Control and Traction Control hold back power though.

The clunking is the stupid Yoke sliding back and forth not the transmission.

Been an issue for years. I do fault them for not coming up with a solution.

SLOW3R · November 29, 2014

I guess I will give the ECU a little more time and see if this thing gets any better. It not, back to the dealer it goes, and hopefully they can tune it or something.

gilleydog · November 29, 2014

sprint booster and e85 that will wake it up

SouthernSilveradoGuy85 · November 29, 2014

I have the same truck as you. The throttle response is probably because I'm sure you have 3.08 gears like I do. I plan on swap them out for 3.73s.

As for the transmission, mine did that sometimes, but it stopped. It's almost like it had to break in. I'll add that it would shift hard when I didn't hot rod around, which I know if you hot rod around the transmission while shift hard because it thinks you'll take off fast.

You shouldn't feel it switch between V4 and V8, even though I have felt it once in awhile. The way I know is by the exhaust since I have a Flowmaster.

As for the mileage, I'm really not sure. I was getting the mileage it was supposed to. Of course after having my exhaust done it's gone down because I can't help but get on it lol. It still can get 22 mpg on the interstate in V8 mode though. So I'm not sure why yours is so low. Have you checked your tire pressures? Being uneven or to low will kill your mileage. I check mine weekly, not as much now since it's gotten cold though. When I check them I don't go by the truck, I use my gauge. Seems like the TPMS seems to read about 2-3 psi lower than what my gauge says, but they do stay close to each other so they're somewhat accurate.