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rayjr2785 03-28-2011 08:27 PM

Idle at 500 RPMS and shakes while stopped
I have a 2006 WK limited with the 4.7V8. It has 88k on it and I purchased it about two months ago. Not sure of the service history, but the car runs good other than the idling. I have never owned a jeep and at stop lights or in park the car idles at 500 RPM'S and it shakes/shutters-is this normal?

Has anyone experienced this and if so what have you done to fix it? I've searched this forum, but I haven't found anything regarding my specific issue.

To date:

I installed the OEM spark plugs (two weeks ago) and it didn't solve the shakes/shuttering.

I brought it to a Jeep dealer last week and they told me it is idling normally, but I couldn't imagine that rough idling would be normal.

Any info. would be great!

Thanks Ray

lll2for3lll 03-28-2011 09:03 PM

Re: Idle at 500 RPMS and shakes while stopped
Clean the throttle body and PCM flash. Two simple solution that will for sure solve your problem.

And maybe replace the PCV and EGR valve.

2005JGC 03-29-2011 12:49 AM

Re: Idle at 500 RPMS and shakes while stopped
I am not going to lie... the 4.7 is an engine that I have found pretty commonly to have a kind of unbalanced "shake" or "shimmy" to it. it feels like a slight misfire. Some are much worse than others. I notice it kinda come and go on mine.

At work I replaced intake valves and keepers due to a coldsoaked misfire. This one in peticular had a very noticable shake to it when I pulled it in and I kinda figured that would be resolved with the new intake valves... it did not at all, it shook very much even after, but no more cold misfires.

BTW, my PCM is up to date and so was the other one, and my throttle body was removed and cleaned thoroughly, IAC removed and all when I put the engine back together 6 months ago.

Your idle speed is normal.

your issue may be a failing (sticking) egr valve, on the one previously mentioned that was something I checked and it was not. you can check it by loosening the bolts to the egr tube, remove it from the intake manifold and plug the hole, if it clears up you know its allowing gasses to flow.

rayjr2785 03-29-2011 07:44 AM

Re: Idle at 500 RPMS and shakes while stopped
Thanks guys. I'll definitely look at the egr valve and have the PCM updated..Throttle body looked clean... It's not a horrible shake, but I guess if the flash and egr are not to blame, I'll probably just leave it alone.

Djsal5 04-08-2011 07:36 AM

Re: Idle at 500 RPMS and shakes while stopped
i had work done try disconnecting the battery for 10 mins then hook it back up the computer relearns everything

mitchelm 04-09-2011 01:28 PM

Re: Idle at 500 RPMS and shakes while stopped
Also, were the spark plugs gapped appropriately?

robpp 04-09-2011 01:32 PM

Re: Idle at 500 RPMS and shakes while stopped
i have a 4.7 does this too when its hot. itll idle down a touch below 500 and then i get the shake. I used the superchips to make my idle 550 and that seems to have fixed it.

jeepgcoman 04-09-2011 09:07 PM

Re: Idle at 500 RPMS and shakes while stopped
Everyone has good input/suggestions, but just be aware that these engines are completely electronically controlled and utilize numerous sensor feeds to the PCM. The PCM then sets engine parameters according to these inputs. Without having a way of checking and verifying the accuracy of the various sensor inputs it'll probably difficult to hit on the cause, unless someone has had the exact problem along with the solution that fixed it. IMO, that's why these forums are so neat. After reading some of the problems and solutions, I think many of us could go to the dealer/mechanic and tell them what's wrong and how to fix a given problem.

Anyway, off the soapbox. I don't believe your idle speed should be that slow under any normal condition. Rob fixed his with the SC tuner (a good choice, IMO), but I can't believe the normal curb idle would be so slow that causes the loping and shaking. Has anyone looked up what it should be? I know my WK 5.7's stock idle is ~625 RPM and my LX 5.7's stock idle is ~650 RPM. I've done like Rob and bumped them both up ~50 RPM, just because it's my preference.

hummer recovery team 08-16-2012 11:24 PM

Re: Idle at 500 RPMS and shakes while stopped
My jeep is doint the same thing I replaced the tps and iac as well as the map sensor and on monday i replaced the plugs with stock champs and gapped at.40 nothing changed I than seafoamed and nothing changed it will idle at about 500 when before it would be at 650, im thinking egr valve?

WK2007 08-18-2012 03:44 PM

Re: Idle at 500 RPMS and shakes while stopped
I am having the same rough idle issue as you describe. Mine only does it intermittently, but at times it is rather rough. I have had the PCV valve, sparkplugs and an induction cleaning and nothing has helped eliminate the problem. Although the engine does run alot better, the terrible idle is still a nuisance to me. On Friday next week I will have my EGR valve replaced and I will post the results. I am also trying to diminish an audible tick when accelerating, so hopefully I can report some hopeful news back to you by next weekend.

WK2007 08-23-2012 01:37 PM

Re: Idle at 500 RPMS and shakes while stopped
I just had the EGR valve replaced and I can say that nearly all the rough idle is now gone. For $55 for the EGR valve through Rockauto plus $37.50 for the install, the issue appears to be resolved. I have not yet had a chance to measure any improvement in gas mileage, but time will show. Hope this helps you in deciding whether replacing the EGR valve may be an option in your situation. Good luck!

hummer recovery team 08-23-2012 07:16 PM

Re: Idle at 500 RPMS and shakes while stopped
thanks i will replace it

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