Rough idle that will not go away - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > WK Grand Cherokee & XK Commander Forum > Rough idle that will not go away

Dan's Old as Dirt Birthday Sale!Premium LED Lighting by VISION X, Proudly sold at ROCKRIDGGEARSHADE Pocket Tops in stock and available at ROCKRIDGE

Reply
Unread 05-04-2013, 08:18 AM   #1
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
Rough idle that will not go away

Hi all this is my first post to this forum. I recently purchased a 06 3.7 with 118k miles on the clock currently and I love it except for the rough idle it has developed.
I have no codes showing
I have followed all the tips in other threads and so far:
I have installed a new tps
Changed spark plugs (got them at the dealership gapped to .042)
New PVC valve
Cleaned throttle body
Ran injector cleaner through tank
Cleaned iac motor
Checked trans fluid level

It still dips below 500 rpm at lights and bounces back up and has a shake at idle
What should I look at next?

jboylan is offline   Reply With Quote
Unread 05-04-2013, 08:52 AM   #2
paroxysym
Registered User
2007 WK 
 
Join Date: Jan 2005
Location: Baltimore, Md.
Posts: 3,710
have you done seafoam through the brake booster?
__________________
2007.5 WK Laredo 4.7
OEM+
paroxysym is offline   Reply With Quote
Unread 05-04-2013, 09:01 AM   #3
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
Not yet. I'm having trouble finding the thread with the write up for that. Do you know the procedure?
jboylan is offline   Reply With Quote
Unread 05-04-2013, 09:36 AM   #4
paroxysym
Registered User
2007 WK 
 
Join Date: Jan 2005
Location: Baltimore, Md.
Posts: 3,710
locate the brake booster- theres a vac line connected to it, disconnect it and pour the bottle of seafoam in the line, slowly- almost making it stall out. let it sit for 20mins after dumping the whole can in the jeep. go out start it up and take it for a spin, and really keep the RPMs up to burn all that seafoam/carbon build up out of the motor. should help
__________________
2007.5 WK Laredo 4.7
OEM+
paroxysym is offline   Reply With Quote
Unread 05-04-2013, 10:30 AM   #5
enkeivette
Registered User
 
Join Date: Mar 2013
Location: Placentia, CA
Posts: 119
I would have guessed the idle slot/ port in the throttle body, if the problem is only at idle, you sure you cleaned it well enough? Change the fuel filter, pull out the injectors and hit the tips with carb cleaner, finally check the sock in the gas tank for a clog.
enkeivette is offline   Reply With Quote
Unread 05-04-2013, 10:40 AM   #6
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
I thought the fuel filter for the 3.7 was on the fuel pump in the tank? Is there one on the frame or in the engine bay?
jboylan is offline   Reply With Quote
Unread 05-04-2013, 11:10 AM   #7
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
Tried the sea foam and no change. Still surging and rough idle.
jboylan is offline   Reply With Quote
Unread 05-04-2013, 12:33 PM   #8
ca07wk
Crawl-Offroad.com
2007 WK 
 
Join Date: Aug 2012
Location: San Diego, CA
Posts: 945
Fuel filter is in tank.
__________________
Crawl-Offroad.com-Boycott Paved Roads
2006 WK Limited Modified QT2
OME HD/HM UCA/Toyo AT2 on Moabs/JKS Rear Discos/Steel Armadillo Skids, Sliders,Front Shackles,Antenna Mount/Crawl Rear Skid
ca07wk is offline   Reply With Quote
Unread 05-04-2013, 04:10 PM   #9
mg2125
Registered User
2006 WK 
 
Join Date: Feb 2013
Location: Wauconda, IL
Posts: 6
Sounds dumb (and if you've installed a cold air induction kit then it's a moot point) but I traced a similar problem on my WK to an incorrectly latched air box lid. See I had replaced the air filter during an oil change and did not install the top of the air box correctly; as soon as I reattached the lid correctly, the idle problem went away.
mg2125 is offline   Reply With Quote
Unread 05-04-2013, 05:14 PM   #10
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
I just checked. Lid is secure. Thanks for the tip tho
jboylan is offline   Reply With Quote
Unread 05-14-2013, 05:54 PM   #11
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
Update: took the jeep in for p0023 and p0506 code that got thrown on my trip last weekend. They also found u0401 and said that the sensor parameters were way off and I was getting bad signals from the new sensors. My mechanic reset everything yesterday and it ran fine this morning. I had all the same codes come back this afternoon and went away and came back and went and so on. The only one still there is u0401. Invalid data from ECM pcm. Is it time to order a new computer(ECM/pcm)???
jboylan is offline   Reply With Quote
Unread 05-16-2013, 09:41 AM   #12
chevra
Registered User
2008 WK 
 
Join Date: Jan 2013
Location: esterhazy, SK
Posts: 219
I had a bad o2 sensor cause similar problems once before.
__________________
{08 Grand Cherokee North Edition} {3.0L CRD} {17" XD Addicts with 245/70/17 DuraTracs} {Rusty's Strut Spacers} {GDE Eco Tune and DPF Delete}
chevra is offline   Reply With Quote
Unread 05-16-2013, 09:57 AM   #13
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
Just changed o2 2 hours ago. Stuck in traffic right now on I-81 and the idle keeps dropping out and getting rough. Hasn't stalled yet but it feels like it wants to. Also noticing some rough shifts when I'm on and off the gas in traffic
jboylan is offline   Reply With Quote
Unread 05-16-2013, 02:22 PM   #14
sunnysal
Registered User
2006 WK 
 
Join Date: May 2012
Location: san salvador, el salvador
Posts: 25
I have the 4.7 v8 and have the same problem. I replaced; MAP, TPS, IAC, PCV Valve, Spark plugs and the air filter. still have VERY lumpy idle, has never stalled though. I get about 10.5 miles to the gallon, which seems low to me. the advice here led me to change all those items but still it has a crappy idle. I will be watching your thread to see if and how it gets solved. regards, T
sunnysal is offline   Reply With Quote
Unread 05-17-2013, 04:41 PM   #15
jboylan
Registered User
 
Join Date: May 2013
Posts: 9
It must be something in the transmission. I had to have it towed off the highway today. It lost power and started slipping. I'll keep you posted next week as to what they find wrong. They said probably the pump or the valve body but I will post as I know more
jboylan is offline   Reply With Quote




Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.