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Discussion Starter #1
Hello All. I posted on this back in June when I first bought the vehicle. ('07 2wd - 4.7 flex fuel engine - regular gas). I noticed that during the 500 mile break-in, on occassion, engine idling seemed to drop to 500 rpm's and idled a little rough.
At first oil change (3000 miles), I mentioned this to the dealer about the occassional rough idle and their response was that it was within the engine's "normal operation".
Question being, seeing that the dealer seems to think that this idle is within the computers tolerances and unadjustable, would there be an independant shop capable of bumping up the idle by maybe 200 rpm's just to smooth it out? (Currently 50% of the time with variable rough idle). Thanks guys - Brad
 

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Not sure on the Commander... on the Cherokee, there is an idle position set screw on the throttle body which will allow you to adjust the idle speed.

I am not sure that you need to adjust it though. Adjusting it too high can cause other issues.
 

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Discussion Starter #4
It's not about the sound but about the fluxuation between 500 rpm's and 600/650's, what I would consider a normal smooth idle speed. At about 650 rpm's the truck seems smooth and happy. The issue is that it drops to 500 and has a rough noticable idle.
 

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I'm guessing he is just getting a rough idle??? I'll pay attention to mine, although I have the 5.7 I have noticed the tach drop down to 500 once in a while. Do you use regular unleaded fuel?? I don't know much about the flex fuel stuff.
 

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Discussion Starter #7
Again, it's not about performance and I realize that it is not broken. The engine idles rough 50% of the time, with a feeling of a slight miss or as in the case of my old '93 grand Cherokee, when the engine mounts were worn out.
I noticed in a prior post, in an industry report about the newly developed 4.7 V8 due out next year, that amongst other things, the newer engine would have a smoother idle.
I'm not asking to fix a problem - more to the point or the possibility of slightly raising the idle speed to where it is noticeably smoother.
 

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jbmphoto said:
Again, it's not about performance and I realize that it is not broken. The engine idles rough 50% of the time, with a feeling of a slight miss or as in the case of my old '93 grand Cherokee, when the engine mounts were worn out.
I noticed in a prior post, in an industry report about the newly developed 4.7 V8 due out next year, that amongst other things, the newer engine would have a smoother idle.
I'm not asking to fix a problem - more to the point or the possibility of slightly raising the idle speed to where it is noticeably smoother.
If you really have concerns that it is not performing right, take it the dealer to check it out (not just push you off, but actually check it out). However, note that the CAN system will most likely report back any issues like misfires, low idles speeds, etc. via a MIL illumination.

By the way, the revised 4.7L V8 is out now in the 2008 Commanders.
 

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RedCommander said:
I guess my real question is. How does that negatively impact performance? Meaning, if it isn't broken, there isn't anything to fix.
I have the same issue from time to time ... it basically feels like the Jeep is going to stall or it "sputters" when you give it gas. Dealership here (Austin, TX) said it was normal too. I dont think it's normal, but it hasnt failed me yet so I've just learned to live with it. :confused:
 

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Discussion Starter #11
It seems from my initial report/ thread when I first purchased back in June there has been no other concerns or threads concerning this. As well, according to my dealer there is not currently a "manufactures bulletin" concerning the low idle issue. So that leaves them out.
From some of the other posts above I'm not sure of the percieved attitudes towards this. Rather in my post, I was just inquiring whether or not it was feasible to just 'tickle' the idle slightly to improve the roughness. There has to be a simple way to either re-dial it or or to be able to adjust it mechanically. I'm sorry to hear that the other 'poster' above feels that he has learned to "live with it". I certainly won't and will keep this thread updated when I find the solution. Good luck at your end - and keep us informed. Brad
 

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Other than running rough, does it ever die or stall? This is not the answer to your question, yet....
Do you go to the same gas station each time?
What octane do you run?
Have you ever added an additive? (evaporate water)
you have a 4.7 right? Do you run the 85 fuel? If so, stop.

If your Commander idled only at 500 rpm and was rough, I would think just bump the idle. But if it fluctuates, it may be something different......

I run 89 and have no problems. It also increased my mpg. The result in paying more for fuel, cost less. I am avaraging .8 mpg better, which saves me .05 per mile. I say this not because I am thrilled to save .05 PER MILE but it actually costs less for me to run 89. This might solve your rough idle.

Start with running 89 octane first from a different fuel stop. It may take a couple tanks to clear the system if that is the problem.

I am thinking it could be water or bad fuel that causes it to fluctuate.
I used to go to a local cut rate station and my car (yes a 4dr 2wd ugly.... car) and it always ran poorly on thier gas.

Gas companies change thier mixtures thru the year based on weather changes. This can have a negative effect on your idle as well....tell us how this goes.
 

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Discussion Starter #13
I use the same Shell Station down the road from the house and since the time my good-looking truck was new I've used 89 octane. Jeep has always made a great vehicle, I've had three, and the Commander in all areas has been more than I would have ever expected. It's just that damn idle issue and for whatever crazy reason no one seems to or be able to, address it.
 

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Discussion Starter #14
Lime Jeeeep!
Hope you got my message/ response on the rough idle thread. Actually bought the vehicle from a dealership in Brandon.
 

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mine does it too..bad...drops form like 600 to like 400 rpms randomly when stopping at a light etc..hasnt died yet but feels like it going to any day, runs like a champ any other time...im gonna try going back to 89 octane, cuz i seem to have noticed it more lately and im trying to figure out the change, i always get gas at the same spot etc..it is annoying though ill give ya that..
 

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jbmphoto said:
Lime Jeeeep!
Hope you got my message/ response on the rough idle thread. Actually bought the vehicle from a dealership in Brandon.
both my jeeps were bought at ferman but there service sucks

i have not read that thread.i will have to search or if you have it readily available ,if you could PM it to me.thanks

as for running higher octane .i don,t think i should have to if it is designed to run on 87 as it states in the manual.it should run safely.no if and or buts.if it continues and places my family in jeopardy i will get a lawyer.i should not have to worry about my family riding in a $32k product
i am not trying to be confrontational.and i,m not a letigis person but if a law suit is what it takes ,i,m sure theres a dewey,cheatum and howe somewhere that will take up the case
 

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says it eill run, but it doesnt say it is the best. stations change thier mix. Octane burns different rates and the weather can change it.

Try running a coupke tanks with a fuel additive. Air intake can change your performance too.

Check the fittings and air filters too.
 

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Discussion Starter #18 (Edited)
Cico 7 thanks. I appreciate you trying to work with me on this. I'm not a gear head but will definitly get under the hood - check fittings and air filter etc. Also, next fill-up will run some fuel conditioner through the system though I doubt it's the fuel. Now have 5000 miles on the truck and the varied fill-ups don't actually make a difference. What about an independent shop to diagonose the problem? 'Cause the dealership says it "falls" within their limits. Thanks again.
 

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If you know someone who can check it out, that would be great. Getting an independant shop to check it out may be the only way to go. Bug the dealer...take it in again. afyer the 3rd shot call the Chrysler zone office and complain....see if the Zone service manager can help.
 
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