2013 stock Ram hunting/surge while driving at power

[Kirwin]

I am on a RV trip out west towing a 21K 5th wheel with my 2013 Ram 3500. The truck is all stock and currently is at 71K miles. I’ve owned it since it was new. It has developed an intermittent issue that I would best describe as hunting like there was a dead spot in the throttle rheostat at power. It is enough that you can watch boost pressure remain constant until speed drops 5-6 MPH and then it’s like realizes it’s slowed down and turns on and boost pressure rises like you stepped down on the throttle again. It happens on cruise control or with you feeding it using the pedal. Air, oil and both fuel filters changed 10K miles ago in early April. Burning Flying J fuel. Truck is all stock. No unusual fuel or DEF usage. No check engine lights or codes. Its been hot out here, but the truck has been pulling fine. I’m going to change oil and fuel filters next week, but I can’t see how that would be the problem. For those that have has a turbo actuator failure did you notice this symptom prior to your failure? TIA. Ken Irwin

 

[josephc1]

Try cleaning the MAP sensor at the air horn, cured the issue I had.

 

[SnoKing]

I am on a RV trip out west towing a 21K 5th wheel with my 2013 Ram 3500. The truck is all stock and currently is at 71K miles. I’ve owned it since it was new. It has developed an intermittent issue that I would best describe as hunting like there was a dead spot in the throttle rheostat at power. It is enough that you can watch boost pressure remain constant until speed drops 5-6 MPH and then it’s like realizes it’s slowed down and turns on and boost pressure rises like you stepped down on the throttle again. It happens on cruise control or with you feeding it using the pedal. Air, oil and both fuel filters changed 10K miles ago in early April. Burning Flying J fuel. Truck is all stock. No unusual fuel or DEF usage. No check engine lights or codes. Its been hot out here, but the truck has been pulling fine. I’m going to change oil and fuel filters next week, but I can’t see how that would be the problem. For those that have has a turbo actuator failure did you notice this symptom prior to your failure? TIA. Ken Irwin

This is a known problem on cruise control at higher elevations 5000-6000 and above. Had it a lot with the 2015 towing the trailers down through Nevada on 93. If you display the boost gage you will see it stick at 10 PSI. Several of us here have posted the same issue. Seems to only happen with cruise control.

Oh, and my did if I was towing at 60 MPH in 5th gear. If I increased speed to 63-65 it did not occur as much. That was with 3.42 gears. With 4.10 in 6th you are at a similar RPM.

SnoKing

 

[Kirwin]

Thanks Snoking. I tried searching but nothing really came up. Nice to know it’s expected. Just the way the electronics works at high elevations I guess. I’ll take a look at the Map sensor too, but it always looks spotless when I pull the air filter top to change my oil so I don’t mess with it.

 

[josephc1]

The sensor at the intake horn just under the egr valve coil is the one that would need cleaning, can soot up pretty good and cause problems.