since i bought the truck it has been idling low and slightly rough. when warm it idles at around 490-510 and can feel it being a little rough. but at a stop, on the brake, and push the gas a little to 1000 and let go it will drop and stay to 700 and run smooth until i start moving.

truck is a 03 hemi with 34k on it and i just replaced the plugs. what is it supposed to idle at? and is there any way to raise it?

 

my 03 did the same thing, my problem was a bad pcv valve. take your throtalbody off and look down into the intake manifold, if you see oil in there then your pcv valve is bad, its about thirty bucks for a new one

 

what does your truck idle at?

 

when its warmed up, about 600 any other time closer to 700, when i had the problem it was at about 500

 

I just went through this problem too, Things you should check: Clean the TB, Replace the PCV, Check and Replace the EGR (if 03s have one im not sure), and check the plugs. I had the low idle right at 500 and did all of these except the plugs and it didnt change anything, BUT i never had a rough idle. I finally just bought a diablo tuner to raise the idle myself. Since you have a rough idle I would start by checking out that Throttle Body and PCV valve.

All you have to do is take off the big plastic breather tube and there are 4 bolts and a wiring connector holding on the TB, I cleaned mine with brake parts cleaner and a rag. If you look to the left of the TB there is the PCV valve that you can just twist right out, I just replaced mine but I dont think it was faulty. If you can see a bunch of junk gumming up the insides of it then thats your problem. (assuming you have the HEMI then all this applies, im not sure about the 4.7)

 

its not really a rough idle. more like a random shake from running to slow. as long as i bump it up a little, it smooths out. ill check the pcv and TB tomorrow. the only way to raise the idle is with a tuner? cant the dealer do it?

 

i just looked on the diablo website. you cant do anything to an 03 but they sell one for it??? for example it says idle rpm drive/neutral 04-2010

 

Yeah I see that too, I think you can advance the spark and such, but most of the options are for 04+. And no the dealers all told me that 500rpm was normal, and that they couldnt do anything about the idle, which is BS to me. I called 3 different dealers and got the same thing. If all else fails, you can get a 180 Thermostat and trick your computer into higher idle because the comp will think that it is always in warming mode. But before you go that route, definately check those other things first!

 

Yeah, I'm having the same problem with my 4.7. It'll get close to cutting off about every time I stop and sometimes it will. I cleaned the throttle body and it didn't really help but I'm gonna try the pcv valve. Has 110,000 miles.

 

My 05 Hemi is doing the exact same thing, and when I was out for lunch today everytime I came to a stop Id tap the gas and it would idle perfectle around 600. I just cleaned my TB a month or so ago, and I changed the EGR about 2 months ago, so I guess I'll check the PCV valve. Let me know if you figure it out!