36 replies to this topic

[nlloyd]

Here's my story:

I bought an '07 Silverado in August of 2007. The first truck I purchased was a black, 4 door, z71, LTZ with the 6.0L Vortec Max engine in it. I drove that first truck for 8 days. During those 8 days, the truck leaked 4 quarts of oil. The only warning I had was a knocking sound in the engine. No temperature warnings or oil level warnings. Nothing. Just a bone-dry engine after only 8 days. So I called the dealership and told them I was bringing it in, and that I would be expecting another truck just like it. Who knows how long I was running that engine on 1 quart of oil. It turns out, the main oil pan seal was screwed up and none of the sensors for temperature or oil levels were engaged. Oh, just overlooked it. Who knows what kind of scoring the engine cylinders had. Bottom line: I was pissed. And I wanted what I paid for: a flawless new truck. Had I not been personal friends with the owner of the dealership, I probably would have been stuck with that first one. But I got a new one, not a z71, but a 4x4. I let that go because they just didn't make a whole lot of z71s with the Max motor in it.

Well, 20,000 miles down the road I had some very serious transmission problems on the second truck. I pull a boat with my truck, but that doesn't mean the damn transmission should have to be re-built at 20,000 miles. I have been told that they use/used the same transmission in the 6.0L as in the 5.3. That just doesn't make sense to me. There definitely should have been a transmission designed to handle the torque and power of the Max motor. However, I had the transmission fixed, under warranty, and I still love it. I guess I am just too loyal to GM trucks. It has been a rough one with these first year production models (2007).

I said all that to say this: I have been approached by one other complete stranger about the transmission issues of this truck (exclusive to the Vortec Max motor). They complained of the same things I do. The majority of the time when I get on the gas, the motor bogs down until about 3800 rpm, then takes off like a rocket (and it does). Also, at low speeds, it shifts very hard out of first gear, and sometimes second. All in all, the truck is not what it should be with a 400 horse motor in it. I think the transmission limits the motor.

If anyone has any thoughts or suggestions as to any solutions, etc. please let me know. Or if you just feel like empathizing with me, feel free.

Thanks,

NL

[VMax2007]

The 6.0's do NOT have the same tranny as the 5.3's. They have the 4L70E and the 5.3's have the 4L60E. The 4L70E is heavier duty (more hardened components). No issues with mine.

[Punmax]

My truck shifted from the first gear to the second one very hard too...so I took it to the dealer and they reflashed my trucks computer and that fixed the problem.

- And also you said your engine bogs down around 3800 RPM...thats because of the "nannies" gm implemented to keep people from abusing their trucks...a tune should take care of that. Search blackbear!

http://www.gm-trucks...rque management

Edited by Punmax, 14 October 2008 - 03:42 PM.

[RedRock_Z71]

No issues with mine and I have around 28K miles. You're answers have already been given. The Max trannies are different and a tune will fix the delay when you punch it. I have a wicked tune on mine and can completely roast the tires without any problems... yes the 33X12.5X20's as listed in my sig!

[rckt442]

No problems with mine. I tow a 6500 lbs travel trailer and it shifts just fine. I have a large aftermarket trans cooler which keeps my temps below 190 most of the time. I only have 7000 miles on the odometer, so I don't know yet what it will be like once its broken in good. Since gas prices went up, the truck doesn't get used that much anymore.

[MS3DALE]

No issues with mine,As VMax said,the 6.0's do NOT use the same tranny as the 4.8/5.3's.
And as Punmax said,the engine "bog down" is because of the "torque management".

[nlloyd]

Thanks to all. Very helpful information. I guess the guy at the dealership working on my truck knows less than you guys do... he is the one that told me the 5.3 and 6.0 trannys were the same.

Anyway, Punmax what kind of tuning/tuner do you have? I am unfamiliar with reflashing... can you elaborate?

RedRock, can you elaborate on your tuner? Do you know if it voided any of the warranties on your truck? Quit smoking those 33s! That's expensive rubber!

thanks guys

[Punmax]

Wow that guy is a dumbass. And I'm guessing they will reflash your PCM (Powertrain Control Module) since its related to the transmission. There are several sensors in the engine/tranny that feed into the trucks computer and the computer takes all of this information and tells the engine how to act or the transmission when to shift. I'm not sure what can cause the computer to make the tranny shift hard, but when the dealer reflashes your PCM, they basically just reset the thing.

I might be wrong but I'm sure somebody will chime in and correct me!

And Nick...any gains from the K&N Series 63 Air Charger?

Edited by Punmax, 15 October 2008 - 03:06 PM.

[huntervh]

I have a very slight whine coming from the transmission when cold, after about 15 minutes it goes away, or the highway driving is louder than the whine. The next trip to the dealer I will ask them about it.

Other that that no issues shifting or towing.

[66nova]

Thanks to all. Very helpful information. I guess the guy at the dealership working on my truck knows less than you guys do... he is the one that told me the 5.3 and 6.0 trannys were the same.

Anyway, Punmax what kind of tuning/tuner do you have? I am unfamiliar with reflashing... can you elaborate?

RedRock, can you elaborate on your tuner? Do you know if it voided any of the warranties on your truck? Quit smoking those 33s! That's expensive rubber!

thanks guys

Read over this post. It will answer a lot of your questions. To briefly sum it up though, your truck does not actually have a PCM. The NBS 07+ have an ECM and TCM (Engine Control Module and Transmission Control Module). If you want to get the most out of your truck you will have to get a custom tune done. A custom tune is not only better than any handheld tuner on the market, it's cheaper than most of them too. I think you are going to find most people on this forum recommend Blackbear Performance. He can take away almost all of those annoying "nannies" that everyone has been talking about and make your 367hp more like 400 and actually feel like you have that much power.

To answer the question about voiding your warranty. Yes technically it does void your warranty, BUT there are ways around this. Most people purchase a spare set of ECM/TCM's and just switch them out if they go to the dealer. You can purchase them from Justin (Blackbear) for 220 for the pair. The realistic part is that most dealers are no smarter than the guy that told you the that the 5.3 and 6.0 had the same tranny. The 4.8/5.3 have the 4L60E and the 6.0 has the 4L70E. I have 22000miles on my VMax, haul my car with it and I love it.

Hope this helps. These are awesome trucks.

[nlloyd]

66 nova, very helpful my friend. That is basically what I have gathered from reading several discussion topics in this forum. Indeed I have been referred to Justin and Blackbear Performance and I must say, I'm intrigued. I have gathered that you and some other guys on this forum are meeting somewhere in Dallas, TX to have your trucks tuned? Is that right? I live in Dallas and would love to get in on that December date. However, from what I can understand, you can also do a mail-order tuning, correct? Can you explain the main differences here and why you preferred to meet Justin in Dallas? And also how the process works (procedures, costs, etc.)? If you like, you can just tell your particular story for wanting to get your truck tuned.

At any rate, it sounds like you need a good tune in order to get the full potential out of these new trucks. Pisses me off. Probably smart in GM's interest though...100,000 mile warranty and all.

Hunter, I don't experience any sort of whine at all. No irregular noises with my situation. Definitely ask the next time you are in at the dealer. And don't take their crap either. Unless the damn thing is undriveable, the dealers see no problem with your truck. Trust me.

Punmax, the Air Charger does what it promises. I for sure gained the HP it promised (17 I think). Gas mileage seems to be better. It would surely be better if I drove more conservatively. My DIC mileage is all out of wack because of pulling the boat. But I have gained probably 1-2 mpg. You can just feel the engine breathe better. I have heard that a throttle body spacer can help even more. Be warned, the K&N definitely makes the engine louder, but it's not bad and sometimes I like the sound. It was also easy to install. Be sure to ask your service dept. if they consider it to void the warranty before you get it. Mine had no problem with it.

I will shut up now...

Thanks again guys.

NL

[66nova]

66 nova, very helpful my friend. That is basically what I have gathered from reading several discussion topics in this forum. Indeed I have been referred to Justin and Blackbear Performance and I must say, I'm intrigued. I have gathered that you and some other guys on this forum are meeting somewhere in Dallas, TX to have your trucks tuned? Is that right? I live in Dallas and would love to get in on that December date. However, from what I can understand, you can also do a mail-order tuning, correct? Can you explain the main differences here and why you preferred to meet Justin in Dallas? And also how the process works (procedures, costs, etc.)? If you like, you can just tell your particular story for wanting to get your truck tuned.

At any rate, it sounds like you need a good tune in order to get the full potential out of these new trucks. Pisses me off. Probably smart in GM's interest though...100,000 mile warranty and all.

Hunter, I don't experience any sort of whine at all. No irregular noises with my situation. Definitely ask the next time you are in at the dealer. And don't take their crap either. Unless the damn thing is undriveable, the dealers see no problem with your truck. Trust me.

Punmax, the Air Charger does what it promises. I for sure gained the HP it promised (17 I think). Gas mileage seems to be better. It would surely be better if I drove more conservatively. My DIC mileage is all out of wack because of pulling the boat. But I have gained probably 1-2 mpg. You can just feel the engine breathe better. I have heard that a throttle body spacer can help even more. Be warned, the K&N definitely makes the engine louder, but it's not bad and sometimes I like the sound. It was also easy to install. Be sure to ask your service dept. if they consider it to void the warranty before you get it. Mine had no problem with it.

I will shut up now...

Thanks again guys.

NL

You can do the mail order thing with Justin and get a very good tune. He has a data logging cable that he can send to you and get the info he needs from your truck, but the Live Tune is just more personal. He can get at better feel for what you want and what your truck wants (every single truck is different, that part of the reason the generic tune you get out of a handheld is not as good). Plus, it is cheaper! Right now, it cost 200 (if you get your deposit in before Oct 31). After that, I believe the price goes up to 300. Justin will also make adjustments in the tune for free.

The Live tune session is Dec 12-14 and I believe there are still spots open. It is going to be held at my clinic. The two or three post about the tune have directions of just ask and I can give them to you.

[c4cruiser]

I just bought an '08 Silverado Ext cab 4x4/Z71 with the VortecMax 6 liter motor. I asked the sales guy about towing and he said that I should not tow anything for the first 500-600 miles and also to go easy on the trans; no hard acceleration, no manual downshifting, no WOT operation.

So with about 1100 miles on the truck, I towed my car trailer for the first time. The car and trailer weigh about 5400 lbs. The few trips I have now done towing this setup were all on flat land and speeds didn't exceed 60MPH. No noises, no strange shifting issues of any sort.

Were you advised to not tow for the first 500+ miles? Did you go easy on the driveline during that time?

So far, the only thing I really don't care for in the truck is the 3-4 second delay when trying to accelerate without forcing a downshift. I don't expect to do any sort of tune as I am otherwise happy with the performance compared to my old 99 Silverado with the 270HP 5.3 motor.

[nlloyd]

Yes, I did as instructed when I bought the truck and did not tow anything until it had at least 500 miles on it. Truthfully, I didn't tow anything substantial until it had about 15,000 miles on it. I went easy enough on the drive train as well. Looking back, I probably did abuse it a little, but it is just because I was trying to get the truck to do what I knew it should do. And by abuse, I mean flooring the throttle. No burnouts or crap like that.

I too hate the 3-4 second delay in acceleration. You're right about it performing better than the 270 HP motor, but you just bought a 367 HP motor. It should behave like one.

Drive the truck with care and you will have no issues. You bought a great truck, don't worry about it. Sometimes I think the computers cause more headache than they are worth!

-N

[M. Cueva]

Yes, I did as instructed when I bought the truck and did not tow anything until it had at least 500 miles on it. Truthfully, I didn't tow anything substantial until it had about 15,000 miles on it. I went easy enough on the drive train as well. Looking back, I probably did abuse it a little, but it is just because I was trying to get the truck to do what I knew it should do. And by abuse, I mean flooring the throttle. No burnouts or crap like that.

I too hate the 3-4 second delay in acceleration. You're right about it performing better than the 270 HP motor, but you just bought a 367 HP motor. It should behave like one.

Drive the truck with care and you will have no issues. You bought a great truck, don't worry about it. Sometimes I think the computers cause more headache than they are worth!

-N

Do the tune!!!