2003 Dodge Ram Rough Idle / stalling

AES2716

MEMBER
2003 DODGE RAM
V8
4WD
AUTOMATIC
78,000 MILES

Hey guys, I have a 2003 Dodge Ram with the HEMI. It has some intermittent engine problem where some days the idle is really rough and other days it is just fine. It repeatedly posts and clears a cylinder misfire engine code over several days span, on/off/on/off.

I have taken it to the dealer here 3 times over 6 months for this. They keep replacing things and charging me $$$ and the problem keeps coming back exactly the same.

I got fed up with them and bought an OBD2 scanner. One problem I see is that even when idling cold, the PCM reports that it is in closed loop mode. My repair manual says this should only be after the engine reaches "normal operating temperature". I cant seem to find anywhere what this normal operating temperature range is supposed to be. Do you guys know this?

The coolant temp reading seems to be accurate, starts low and slowly climbs to 200 deg F, where it stays steady. Do you guys think this closed-loop mode is the problem, or something else?

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,164 POSTS

Normal temp is between 185 and 210. As far as the closed loop, I would say your temp sensor is bad. It tells the computer the outside temp and the coolant temp. If it isn't working correctly, god knows what type of fuel / air mixture you're getting to the engine.