'03 2500HD engine surging

[nhproxr]

Posting for my father. He's got a '03 2500 HD with the 6.0, 4 spd auto, 4.10 gearing, and trailer package. He recently purchased a 33' Glendale 5th wheel camper about 10,500 GVW. Recently went camping up in northern VT with it and had major engine surging problem. Even on level highway the engine seemed to lose power then suddenly surge with power again, almost feeling like it was searching back and forth between gears. The funny thing is though the tachometer stays rock solid and the rpms don't vary??

 

He had me drive the truck empty and I was able to duplicate the problem a little by putting the tranny in second and holding it around 3000 rpm where it would do the same surging to a lesser degree.

 

He has brought it to the dealer and there are no codes and techs can't duplicate problem. Any suggestions???

[rascal]

mine does that a little bit if i'm going slow in cruse control in a low gear than 5th. not really loses power more like someone was pumping the gas. mines a 5 speed. did they try it the way you did?

[catiaeng]

Are you using T/H mode? I get when climbing minor grades at 60-70mph, tach is running 3000+. I hear about torque management in this website, but don't know much about it

 

I just slow down and let the power of the truck take me up the hill not the speed, I don't need to pass everyone all the time.

[nhproxr]

He does use the T/H mode. The truck does it even under light load on a level highway that is the problem. It does it more severely when load is heavier.

 

Its almost like there is a cylinder missing or something, but no variation in the tachometer. Truck only has 10K miles on it.

[Scyry]

If you can consistantly make the problem happen, take a tech for a test drive with you driving. It has been the only way for me to get some techs to see the problems I have had.