My 2005 Dodge Ram is giving me a problem. My check engine light IS NOT ON!! To me, it seems to be a problem with the idling. While the truck is in park, it tends to "lunge" in regards to the RPM gage. I may be at 500 rpm and them it surges to 1000 (the numbers are not exact) and then back to 500 and up to 1000 all over again. This condition is not constant. It is sporatic. Any help would be greatly appreciated. Thanks.

P.S.- I have a 4.7 liter engine and it is an automatic.

 

Is just the gauge going up and down by itself or does the motor go up and down as well? My RPM needle does whatever the hell it wants, sometimes it works perfectly sometimes not at all. Try reseting your gauge cluster. Hold in the tripometer needle while you turn your keys to ACC ( accessories ) and all of the needles should sweep across their gauges.

 

Can you tell does it happen at the same time as any other event that would cause more power to be needed from the engine, such as the A/C Compressor kicking in, or a sudden high load on the alternator?

 

What code?

 

Spark plugs. Throttle body cleaning. Seafoam treatment.

These are a few things I would do

 

Had the same problem on a 4.7 Durango. Replaced the throttle position sensor and that fixed it.

 

I can almost guarantee a dirty idle air control valve.... easy to clean and costs practically nothing....

https://dodgeforum.com/forum/3rd-gen...when-cold.html

 

The motor goes up and down as the RPM goes up and down.

 

Simply just starting the truck can cause the problem. Turning on the A/C has no effect.

 

Sounds like a TPS issue to me too.