My '01 when it was stock wouls slip the clutch if I held the brake. I could start off in 5th gear. This 6.7 will stall if you let the clutch out too fast in 2nd gear.Anyone else having this problem?

 

I have noticed something like that. It seems to have flat spots at certain rpms

 

mine gets better with miles, it was bad about stalling when it was new & everything was tight, now you can dump the clutch in 2nd & she'll just roll on, seems to get better all the time! Dusty

 

Mine does the same thing. (And it ###### me off ). At first I thought the clutch needed to wear in a little but that's not the case now. With a few thousand miles on it the clutch should be broke in. It's just gutless on take off. I also had an early 01 and it never did this. Well if you dumped the cluth in 5th it probably would. Atch, in your 01 did it seem to fuel itself and try to accelerate if the computer percieved that it was being lugged on take off? Mine did and I'm not too sure if that was in the stock computer or in a mod I did when it was near new. I sure wish this thing ran as well (and got the fuel mileage) of my 01. If I had not wanted a long bed and 4X4 I would still be in my 01, it only had 60,000 miles on it when I traded. A number of other things lacking in this 07 compared to the 01 too.

 

mine is auto but it has all kinds of bottom end so I dont know why you are having a hard time sorry no help here

 

I agree with BBMC on this guys, the 6.7 does have loads of bottom end, but the problem I think is it takes a little to long for the motor to spool up the exhaust flow. That would really be noticed when dumping the clutch on a standard shift setup.

But really guys the 6.7 has a lot of bottom end, its just very misleading with how bad the throttle response is just off idle, at least till the motor spools out... Just my take on this.

 

Rob Mitch,

I agree with you. I think there is a lack of fueling on low end. Gotta figure out a way to change that. I was getting 21 mpg with the 01 and that was driving in traffic.
Have you had any problems shifting if you push it past 2000 rpms? It seems like the rpms don't want to drop between gears. Mine seems to hold the rpms for 2-3 seconds after the throttle is released and when the clutch is pushed in. I can shift gears before the rpms drop. That's very annoying. The fan sounds like an airplane ready to take off anywhere over 2000 rpms. At least I hope it's the fan.

I wonder if there is a flash for this?

atch

 

atch,

My automatic 6.7 does the same thing for the same reason it has slow throttle response. It takes a little longer to get all the intake air, as well as the exhaust moving through all the system.

So, once it does get things moving just to back out of the throttle, also takes longer for the motor to respond to this action as well. It sucks just plain and simple, I do hope they have a fix for this soon, but I am not going to hold my breath LOL...

 

Atch, mine does the same with the RPM. I would say mine holds the rpm up one to two seconds after letting off the throttle. It shifts OK but I can feel a "bump" in the gear shift every timei go into 5th. I agree on the fan. It seems to get really excessive at a preset temp. I've even had it come on when idiling. Mine has a build date of 3/07 so maybe there is a reflash for some of this.
Twice after starting it ran really crappy with little or no throttle response and sounded a lot like a 5.9 After turning off and restarting all was OK. Has yours ever done this?
I'll have to wait till I can go to the dealer I bought it from, My local dealer I don't trust.
Rob

 

My camaro did the same thing with holding the rpms. Obviously that is complete different vehicle and motor but i had efilive and went through the maps and software and it was made to do that. There were many reasons for it but was more for performance. I guess i could see it helping while towing as long as the rpms didnt stay too high for too long. It will slow the acceleration momentum if everytime you shift, the vehicle has to make the motor catch back up.... just a thought

 

Rob,
Mine has never done that, it runs pretty good so far. It just has some annoying things, I guess I'm going to have to get used to.

I'm not talking about when the fan clutch engages. It seems that when ever I try to pour the coals to it and I go over 2000 rpms, and shift it I get a howling noise that sounds like the fan clutch engaged, but as soon as the rpms drop below 2000, the noise stops.

I'm finding that if I short shift it, it does great