Idle Shake

[FirstDiesel]

People talk about having a lopey idle. I wouldn't call my problem that. What happens at a traffic light is that the idle gets a little shakey or rough. Not often but ever so often. Nothing shows on the tach, can't even say I can hear it change RPM. It just shakes/shudders a little. Does anyone else have this happen??

Truck has 14k on it and the fuel filter is about 2k old.

[TC]

My truck also has an occasional roughness at idle. It is more of a littls spike in the rpm that doesn't make the tach jump, but will cause the truck to surge forward just a bit sitting at a red light. Otherwise it runs fine and has plenty of power.

It is an early 2001 built in October 2000 with 50,000 miles. Fuel filter changed about 4,000 miles ago. I had the software upgraded for the original idle surge a couple of years ago.

[FirstDiesel]

That's not what mine is doing. No surge in power or RPM change. Just a 1-2 second roughness in the idle then it smooths back out. It might do it once or it might repeat itself in a minute.

[The boss]

Same surge at idle for me as well. I will be changing all fluids and filters this week. Ill take the opportunity to talk about it with my mechanic then.