back to dodge again,the same old bs.reflash the computer.my tach was good for a few hours at 750 at idle.now its back to 400 sometimes.sorry guys,this is the biggest POS i have ever owned.Ive had smoking issues,trans shifting ,A/C,tach,in 25000 miles.I had 2 fords.a 93 f350 with 90k and a 95 svt lightning with 160k,I only took my f350 back once.maybe its my dealer?

 

Disconnect your mods. Does the problem go away? It is hard to tell what you have by looking at your previous posts. Your truck doesn't appear to be all stock.

 

my truck does the same thing, idles around 300-400, then when driving will show its reving to 4000, when their is no way it is happening. i need to take it in but know it wont do a thing for them.

 

Read the first stickied thread above about the possible wire rubbing through at the A/C compressor lines above the compressor. That provides the 5 V to the camshaft position sensor also.

 

this may sound stupid but where is the cam sensor?but why does my dashawk say its ideling at 750?

 

My 06 did this also. the tach would flucuate from 400-45- to 750 but the engine RPM weren't changing. No difference in the sound of the engine. took it in to the dealer. After a couple days and STAR involvement, they decided the instrument cluster was bad. Changed under warranty at the time and alls been good since. That was about 20K miles ago.

Ken

 

thats what I think is wrong.but this dealer doesnt wont to change parts for some reason

 

Same thing here. Mine idles around 100 most of the time, and at 130 kph it is around 4000. Dodge dealer did starscan and conclude that instrument cluster is bad. It is about $500 or so, and all my other gauges work properly, so I will put up with the tach (out of warranty)