RPM Surge at highway speeds

[ToboJosh]

I have been experiencing some fluctuations in my RPMs while cruising at a constant speed on the highway. In cruise control and not in cruise, the RPMs will jump around 200 while I am going 50-75 mph. Every time I hit a bump in the road, they surge like I am pushing the gas pedal. The truck doesn't accelerate, it just revs the engine. The RPMs do not surge will idling. Not sure what the issue may be. I cleaned the throttle body a few months ago and there is no check engine light on. Any suggestions on what the problem may be?

 

[WilliamS]

Sounds like torque converter unlocking to me. It could be a million things but in my past its in the transmission somewhere, either the OD gear is slipping or the torque converter isnt locking up. Has it thrown a light? Im not sure what electronics they had back in 2002 to sense slip but its a start.

 

[steermaster]

Kinda had the same deal, if you were to hammer down on the throttle doe sit slip or act up? mine did this... transmission **** the bed shortly after

 

[ToboJosh]

There is no engine light that was triggered.

When I hammer the gas, the truck runs and picks up smoothly. The tranny shifts gears smoothly also. The only problem I am having is when I am cruising at a constant speed around 65mph, it will surge for a second and go back down every so often. It also happens when I hit a bump in the road.

 

[yoda]

Could be a bad spot in your TPS. Causing you converter to lock and unlock, Fairly common.
If you have higher miles would not be a bad idea to change it anyway. Recommend O.E.

 

[ToboJosh]

The truck has 151,000 miles on it. So the TPS would be the place to start at? I have read that it there could be a faulty ground somewhere... not too sure where that could be though.

 

[WilliamS]

Sounds like the OD gear clutches are going out.

 

[yoda]

Without the equipment to diagnose it, yes I would start with replacing the TPS, relatively inexpensive. Easy to change

 

[ToboJosh]

alright, i appreciate it. The truck idles at a low speed and very smoothly.

 

[vault guy]

tobojosh my 2002 is doing the exact same thing can i ask were you able to figure out a solution

 

[MF_MF]

Hi fellas, I just started seeing this on my 2003 Ram, so as vault guy asked a few months ago, anybody find a solution for this?

At speeds over 70 mph, I'll see slight jumps in the engine RPMs, they only last a second. It'll jump from 2000 to 2200 RPM. I also noticed one of the posters mentioning it happened going over bumps...I noticed that correlation also.

 

[JohnnyMac]

I believe if you put the truck in tow mode (I think it disables OD) and it doesn't do it, then that is a pretty good indicator that it's the TPS. If it still does it, then might be the torque converter.