2012 LTZ falls on its face...

[ILSMKU]

I have a 2012 LTZ with a volant CAI and 24" Lexlani DX9 Rims. I dont drive it much (its the wife's), but when I do, I feel like it falls FLAT on its face every time I get it some gas to get going! It will nose dive then immediately HIGH REV and finally get going. Im also getting a lifetime average of 12.5MPG! And this is wife driven 99.9% of the time (slow).

Im here to ask if its normal for the Tahoe to fall on its face whenever you peg the throttle? IF NOT, could it be the Volant CAI (who I had never heard of, but purchased from the truck shop that did my electric running boards)?


Or is this the 4 cylinder to 8 cylinder mode change over that causes the tahoe to fall on its face?

And does anyone else experience the funky shifting points on the highway? Say Im cruizing 75MPH and want to get it up to 80MPH. For some reason, giving it some more throttle doesnt do MUCH at all. But once I give it just a little bit more, it downshifts and HIGH REVS to much. Its like it wants 100% full throttle or NONE at all to accelerate.

Any suggestions?

 

[THE YETI]

Blackbear tune.

 

[ILSMKU]

Blackbear tune.

Are you saying that what I'm experiencing is normal? Could my CAI or big wheels be the cause of this?


And will the tune void my engine warranty? I understand the mag/moss act, but at the same time its easy for a dealer to say, "the tune made more power and put more stress on the engine and drive trian than it was designed for" and its a uphill battle for me to get any warranty items fixed if they know I have it.

 

[JennaBear]

Intake needs to be tuned for. You are probably confusing the PCM with the different airflow. Larger wheels/tires need to be taken into account as well.

 

[ILSMKU]

Intake needs to be tuned for. You are probably confusing the PCM with the different airflow. Larger wheels/tires need to be taken into account as well.

Hi Jenna,

So let me get this straight... am I doing more harm than good running that CAI WITHOUT a tune?

And do 24" wheels need to be programmed to the truck for it to shift properly or something?

Finally, if I was to get a tune, can the dealer tell I have one next time I take it in for service?


Thank you!

 

[JennaBear]

Yes, CAIs need to have a tune to actually give you any benefits. All our customers with Volants have had airflow problems, and were in desperate need of a tune (usually they would see a CEL). Your shift points should be changed for the 24s, especially if your speedo has not been calibrated for them; your MPH/RPMs are almost certainly off.

Since you have a 2012, you would need an AutoCal. As long as you return your tune to stock for dealer visits, you are good to go. With the current methods, the dealer can not detect tuning, so long as it is returned to stock (which you can do with the AutoCal).

 

[Zed 71]

And does anyone else experience the funky shifting points on the highway? Say Im cruizing 75MPH and want to get it up to 80MPH. For some reason, giving it some more throttle doesnt do MUCH at all. But once I give it just a little bit more, it downshifts and HIGH REVS to much. Its like it wants 100% full throttle or NONE at all to accelerate.

Any suggestions?

The 6-speed tranny is funky itself. Assuming you have bigger diameter tires/wheels the odo is off adding to the apparent loss in mpgs. Blackbear will take care of it ...

 

[ILSMKU]

The 6-speed tranny is funky itself. Assuming you have bigger diameter tires/wheels the odo is off adding to the apparent loss in mpgs. Blackbear will take care of it ...

Cool, thanks. I thought I think I had the dealer program the new tires, but I could be wrong.

What are you guys seeing for MPG for city?

 

[JennaBear]

What octane are you running?

 

[THE YETI]

There is a programming update called a VCI (or VIC). If you alter the wheels on a late production 2012+ vehicle, it will effect the way the vehicle shifts. GM has a download that would need to be done and I believe they charge about $45-60 for this.

That is problem #1. Problem #2 is you really should tune that vehicle to get it to run optimally, as indicated by JennaBear. I just said get a Blackbear Tune because that is what I, and 90% of the GM world, use to make their vehicles run like they should.

 

[ILSMKU]

There is a programming update called a VCI (or VIC). If you alter the wheels on a late production 2012+ vehicle, it will effect the way the vehicle shifts. GM has a download that would need to be done and I believe they charge about $45-60 for this.

That is problem #1. Problem #2 is you really should tune that vehicle to get it to run optimally, as indicated by JennaBear. I just said get a Blackbear Tune because that is what I, and 90% of the GM world, use to make their vehicles run like they should.

Hmm, good to know! I will ask my dealer how much to have this done. I do like the idea of the tune and getting ride of 4 cylinder mode too though.

EDIT:

Thank you. I called my dealership and it appear I do NOT have that update. they want 120 bucks + to do it, telling me it will take 1.5+hours to do.

I asked him about the tranny shifting so funky and he flat out told me, he knows it sucks and that I should get a hand held programmer.... LOL! He actually told me that. When I asked him, wont I void my warranty doing that? He said, to uninstall it before I come in, and that only SOME still get flagged after they are uninstalled. He didnt know which ones WONT get caught, but he said they are out there.

Rather than spend 120+ just for tire programming, i think I will spend my money on the turn and tire programming from BB instead.

Now i need to find an exhaust and some a drop kit (wife is begging me for a drop and exhaust).

Thank you and everyone else for the help so far.

What octane are you running?

91?

---------- Post added at 02:32 PM ---------- Previous post was at 02:20 PM ----------

 

[THE YETI]

no problem Don, glad it helped you out.

:shake:

 

[Jmat]

"Now i need to find an exhaust and some a drop kit (wife is begging me for a drop and exhaust)."

Wow man... that's one cool wife you've got there! Maybe she'd appreciate a supercharger as anniversary gift? BTW, go with the BB tune, you won't be dissapointed.

 

[ILSMKU]

"Now i need to find an exhaust and some a drop kit (wife is begging me for a drop and exhaust)."

Wow man... that's one cool wife you've got there! Maybe she'd appreciate a supercharger as anniversary gift? BTW, go with the BB tune, you won't be dissapointed.

Thanks man! No SC for her. She won't let me get one for my ride!!!

 

[KMeloney]

Jenna -- You guys going to be in the Philly area anytime in the near future? (I'd go to central NJ, too, or down to Baltimore...)

Yes, I'm running a tune, but would like to see if it could be optimized via an in-truck session.

 

[JennaBear]

Closest will be DC in Oct.

 

[KMeloney]

Closest will be DC in Oct.

Thanks.

 

[imi4tth3w]

just fyi there is no point in running premium in your vehicle if its not tuned for it.

also the way you explained your symptoms, it almost sounds like the trans is slipping? or maybe the cai is leaking causing irregular revs? anyhow i'd just double check your trans fluid and your intake install make sure everything is good.

reguardless, a tune is going to help everything all around. just some things i thought i'd point out.

 

[Zed 71]

also the way you explained your symptoms, it almost sounds like the trans is slipping? or maybe the cai is leaking causing irregular revs? anyhow i'd just double check your trans fluid and your intake install make sure everything is good.

That is how the 6-speed tranny feels and it is a common complaint.

 

[ILSMKU]

UPDATE:

I installed the Borla catback system and it made a pretty big difference in regards to throttle response. It has ZERO drone and its not loud at all. We are kind of bummed its not louder to be honest. I know it will get a little louder, but even then, I dont think it will be as loud as we hoped.

Im still not happy with how it shifts though. I think my big 24" wheels are just making an already funky transmission even worse.

Black Bear... Im ready for a tune and tire size reprogram or whatever my truck needs.