truck_newbie

Damn. Glad you got your truck back btw. Are they thinking the problem was unrelated to the transmission before? It seems odd for a new transmission to show the same issue unless this is a systemic issue for the 10-speed.

The little issues on my truck are starting to mount up but on the bright side, i went ahead and installed a tonneau cover. I had been searching for weeks because there are so many options. I went with the Gator EFX hard fold purchased from RealTruck for $616 (got 5% off by calling them). Cheapest of all the hard-fold covers but very high quality. It showed as back-ordered for 3 weeks but i got it within the week. Install was easy, there is a video of it being installed on the Sierra on RealTruck's website. I went through a carwash and it leaks a tiny bit in the tailgate area which makes sense because the back as no "seal". You can probably install a back seal if that bothers you. Multi-pro tailgate opens and closes easily. Very happy with it so-far.

Just started hearing this noise on my AT4 when going over bumps. I'm at around 1k miles now. It sounds like a hollow squeak. @AT4guy, did you ever get yours resolved?

Sorry to hear about that and i completely feel your pain. No need to apologize. Sometimes, one just needs to vent. This morning, i went for a drive with the radio off to see if i can readily duplicate all the issues i'm having that way if a loaner becomes available, i can quickly reproduce it for the tech. I definitely hear the squeak on startup for a few seconds then it goes away. Every time the truck auto-starts after a auto-stop, i hear the squeak. I have to remember to turn-off auto-start/stop so the squeak doesn't drive me insane. To make matters worse, i heard what sounded like a new problem. When i go over some bumps at moderate speed, i hear what sounds like a hollow squeak sound when the truck goes over the bump. Sounded like it was coming from the rear passenger side. I'm at 1100 miles right now. The truck was absolutely problem free within the first 500 miles. In my opinion, this is unacceptable for a vehicle that hovers over $60k but i digress. Like you, i'm trying to look at the bright side because the alternative is depressing. I'll give them the benefit of the doubt that these are just QC issues and that they will all be fixed. Fingers crossed.

I think the sound has changed slightly. It is sounding more like shuffling rather than squeaking. I can get it to repeatedly happen if i apply light throttle whether cruising at highway speed or moving from a stop. Did your PCV issue sound like shuffling?

I have been looking for a black grille. Do you still have yours for sale?

I'm hearing mine much more frequently now. Still waiting on a loaner to be available so i can take it in. These can't all possibly be the 10-speed transmission considering how prevalent it seems to be. If it is indeed the 10-speed, then that would be a poor showing for it's start of life considering all the hate the 8-speed got for it's shudder issue. I too suspect we will eventually be told it's normal for the 6.2. Oh well, joys of a first year model.

Your reply made creating this thread worth it. I really like the saying by Daniel Patrick Moynihan: "Everyone is entitled to his own opinion, but not his own facts."

That's a blanket statement and generally i would agree with you if there wasn't any data. Fortunately, there is data. Did you even look at the actual report with the numbers and horsepower/torque charts? I'll summarize below. 5.3 Engine ----------------- Power = 355 hp; Torque = 383 lb-ft 6.2 Engine ------------------ Power (Premium) = 420 hp; Torque (Premium) = 460 lb-ft Power (Reg) = 417 hp; Torque (Reg) = 460 lb-ft I will still be very happy with the 62 hp i'm gaining over the 5.3 compared to the 65 hp i could be getting. I'm sure that 3 hp delta makes all the difference in a 5500 lb truck. Sorry to be sarcastic, just couldn't help it. ?

You are both welcome.

I don't understand your reasoning. People are of course free to put whatever fuel they want in their engine. I see this less of cheaping out on premium fuel and more of what you gain or lose by going regular. This study has proved, and backed it up with scientific data that you don't gain anything by running premium (adjusting for the mpg gain of premium) on the 6.2. Personally, if i pay for something, i want to be sure i'm getting the benefits. I paid extra for the 6.2 engine because i know i'm getting significant extra hp and torque over the 5.3. Based on this study, I've come to the realization that i'm not gaining anything by fueling the 6.2 with premium.

I only fill-up at Shell. In my neck of the woods, they have a sticker that says can contain up to 10% ethanol. I don't know if that also applies to the v-power/premium. Your analysis on timing is what EE in the video explains. An engine that lists recommended is designed to adapt. It will try to advance timing as much as possible because that's what gives the best fuel economy and power. Based on the results in the study, it seems the L86/L87 engine has been tuned to advance timing for fuel economy only. If you switch to regular, it will retard timing and use more fuel but give you the same power. An engine that requires premium will not retard timing by much if at all. That's why the Audi in the study was knocking because it required premium.

Personally, i saw a 1.5 mpg improvement when i used premium. Didn't notice any other difference.

I can understand tuning requiring premium. Is he saying the same for an un-tuned factory car? If so, what facts is he basing this on? There are other advantages to premium such as more detergents. The detergents argument matters less these days because of direct injection so you are going to get carbon build-up on the valves either way.

There have been multiple threads/posts on what fuel to feed the 6.2 beast. Since GM only recommends premium fuel, it’s become a gray area and most people don’t like gray areas. Not surprisingly, there are passionate opinions on either side. I for one am a facts guy and prefer to go with actual numbers rather than some romantic notions of what someone thinks. It turns out this experiment has already been done for the L86 engine. Our engine is the L87 but it makes the same power and torque as the L86 and it seems the only difference is the addition of DFM for the L87. Summary below 1. Knock: No audible knock was observed with regular fuel. 2. Power: Reduction in power was average of 0.7% which evaluates to 2.94hp. I was actually quite surprised by this, I was expecting more. If you claim you can tell a 0.7% difference, then more power to you. 3. MPG: The biggest gain was fuel economy. They recorded an average of 7.1% reduction in mpg with regular. If you live in an area where premium fuel cost is less than 7.1%, then by all means go for it. Where I live, premium is $15 more on a $45 regular fill-up. I’m not here to tell you what fuel to feed your 6.2 but if you prefer numbers like me, then maybe this can help you make an educated decision. Will probably get some flak for this but that’s ok. AAA Report

Both the 12909 and 11229(that i have) are single exits. I'm not sure about the 5.3 but on the 6.2, factory piping is single-in, single-out, you can see in the pictures in my post. It seems the 12909 is a much bigger muffler than the 11229. What I have been told is that generally, the bigger the muffler, the quieter the sound. The 12909 with both flappers might end up too quiet for you. If you go with the 12909, you could probably just try with one flapper first. I ordered the Gibson Part #: GPE-65692. I got it heavily discounted for $450 so i figured why not. I like my current setup but sometimes it seems a bit too quiet. If i end up not liking the Gibson, i'll go to my old setup.

The Flowmaster is definitely much louder than the Magnaflow. Even without the flappers, the Magnaflow sound was pretty tame. I think the Flowmaster with flappers will still be a bit louder than the GM performance exhaust. The GM performance exhaust is really tame.

Make sure you keep your flappers just in-case there is drone. I went with the Magnaflow muffler. You can can read about it here.

Hahaha, fair point.

The new Type-S and Touring are reported to have no drone. I think i might go with the Gibson. We shall see.

I was interested in the Touring but Borla doesn't have any sound clips for it. I emailed them and they said they don't currently have sound clips of the Touring. I'm very hesitant on dropping $1200 on something without at least hearing it first. Currently leaning towards the Gibson cat back. It's less than $600. More willing to take a chance on that since it's half the price. I prefer tamer exhausts. The consensus i'm getting so far seem to indicate the Type-S will be too loud for me.

Yep, there is no mention of radar in the manual (i searched). Hopefully, we will see camera record-ability feature available soon from a 3rd party. Fingers crossed.

Yeah, definitely no interest in paying for it. Now, if they gave it for free, I would gladly accept. ? Has anyone figured out a way to record the rear view mirror camera. Seems like such a waste to have to buy and install a rear view dash cam when there is a perfectly high definition functional one in the car. Maybe GM can do us a solid like what Tesla did for their customers. Tesla vehicles can now record from the cameras unto a usb flash drive. I would actually be willing to pay a little to have this feature.

As far as I know, the Sierra/Silverado don't have radar. Following distance monitor, forward emergency braking, etc are all implemented using the windshield camera.

That's interesting. From the description, i assumed there were no hardware changes. I honestly don't have a need for adaptive cruise. This was more of a curiosity than anything.