[sully75]

I have a 98 ram 5.9 2wd,truck just hit 122,000 and the idle seems eratic in park or drive in park it goes from 600rpm-650rpm like its surging? any ideas? I pulled the codes and there are none! also sometimes my temp gauge will go to 210 then back down to normal and I have noticed it does it everyday. also truck does not lack any power.

 

[slambony]

Might try a TB cleaning, throttle plates and the IAC port. Might just be some carbon in there?

 

[kennethpruett]

The temp gauge going up/down sounds like possibly air in the system.
You should remove the coolant fill cap and let it run up to temperature.

KP

 

[Polar_Bus]

I have a 98 ram 5.9 2wd,truck just hit 122,000 and the idle seems eratic in park or drive in park it goes from 600rpm-650rpm like its surging? any ideas? I pulled the codes and there are none! also sometimes my temp gauge will go to 210 then back down to normal and I have noticed it does it everyday. also truck does not lack any power.

I'll bet it's the IAC piston that's carboned up. I have to clean mine like every other year. As soon as I get the "idle lope" I know it's time for a cleaning. I use Easy Off oven cleaner, and it cleans the carbon right off sweet! Problem solved