H2OBoy

So my '11 JKU has right at 700 miles and from day one has had a bit of a rough idle. It is worse right as and shortly after the vehicle is started. I took it into the dealer to have it checked and they cannot find anything. There are no faults showing and everything checks out on their end. They tell me they really can't do anything until the computer shows an error code or there is a technical service bulletin showing an issue. Any ideas where to go from here? I would imagine the idle is not going to get any smoother on it's own as time goes on.

Battlefrog

Mine is a 2010 sport unlimited and I'm having the same issue right now at 2300 miles. I can feel it and actually see the skip on my shifter....Good thread question...

ronjenx

Well, it might just do that.

Unless it gets real bad, give it a few thousand miles to break in.

Mad-Hatter

try cleaning your throttle body

Battlefrog

True, who knows what's in this outstanding gas we are provided with now days.....

H2OBoy

To be honest I have no idea how to do this. Is this something that should be needed after only 700 miles? I would expect a new vehicle do perform like a new vehicle without having to do my own repairs.

Dronac

Pull off the intake tube. Then spray some carb cleaner on a cloth and open the throttle blade to wipe it down. Do NOT spray it directly on the throttle body. The electronics don't get along with the spray.

I'v heard thd 3.8 has a tendency to get carbon-ed up easily because the 3.8 is lugged so much. In my auto, the RPM's are WAY too low in overdrive.

thrshr01

You have 700 miles on your vehicle. Do not touch the throttle body. There won't be any gunk in there. Wait for the problem to start showing up more where the tech can see it at the dealer. Not every problem throws a trouble code and simply seeing the rough idle will tell a good tech/service writer that your not a paranoid customer and that there's an actual issue. If they notice the rough idle and still insists that they can't fix it since there's no codes, look for a new dealer with a real tech. On the dealer's defense though, if you can't show them the problem and/or they can't replicate the problem...the tech can't diagnose and fix the problem.

Tuto

Check all the ground cables.
Battery negative and all the grounds connnected to it.

Uneasy Rider

At just 700 miles on the odo I would not be cleaning anything yet.

Try a different brand of fuel before you do anything.