# '04 Grand Cherokee Idle Issue **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [June 15, 2010, 7:35pm UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582 "2010-06-15T19:35:16Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![97FormulaWS-6](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/97formulaws-6/32/7384_2.png) [@97FormulaWS-6](https://forums.speedlife.net/u/97FormulaWS-6)\ **Post date:** [June 15, 2010, 7:35pm UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/1 "2010-06-15T19:35:16Z")
'04 Jeep Grand Cherokee with the 4.7 V8. Ran fine yesterday, and most of today. Went to start it when leaving a store and it now idles ~1700 rpms out of gear, and ~1300 in gear. Replaced the battery (was only readying 11V); Replaced TPS, cleaned TB and IAC. Still doing it. Thoughts on what else could cause this? I don’t really want to go spend $75 for a new IAC just throwing parts at it. ---
**Author:** ![CaptainKidd](https://avatars.discourse-cdn.com/v4/letter/c/a4c791/32.png) [@CaptainKidd](https://forums.speedlife.net/u/CaptainKidd)\ **Post date:** [June 15, 2010, 8:01pm UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/2 "2010-06-15T20:01:49Z")
I know it’s a long shot, But when I ahd this problem with my nissan I had to do an “Idle Air Re-Learn” procedure. Not sure if Jeep has the same thing or not. It was a pedal dance with some idle time to let the computer re-learn the volume of air coming into the motor at idle and adjusting the rpms as needed to factory settings. Just a thought, sorry if it doesn’t help. ---
**Author:** ![llink78](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/llink78/32/8037_2.png) [@llink78](https://forums.speedlife.net/u/llink78)\ **Post date:** [June 15, 2010, 9:15pm UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/3 "2010-06-15T21:15:55Z")
I’d have to guess something to do with a vacume leak? ---
**Author:** ![L8APEX1](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/l8apex1/32/7276_2.png) [@L8APEX1](https://forums.speedlife.net/u/L8APEX1)\ **Post date:** [June 16, 2010, 3:02am UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/4 "2010-06-16T03:02:40Z")
> [@llink78](#): > > I’d have to guess something to do with a vacume leak? This. My parents have an 04 grand Cherokee that this happened to. Look on the drivers side within a foot of the firewall, It is a very common problem. ---
**Author:** ![LUKE\_L](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/luke_l/32/7462_2.png) [@LUKE\_L](https://forums.speedlife.net/u/LUKE_L)\ **Post date:** [June 16, 2010, 6:37am UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/5 "2010-06-16T06:37:19Z")
Fuck. I read a bunch of posts and it seems to be 50/50 on bad IAC versus vacuum leak. For some reason cleaning the IAC does not seem to ever rectify the problem on the 4.7 and replacing it is the only option…:shrug: Maybe get the engine smoked? ---
**Author:** ![97FormulaWS-6](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/97formulaws-6/32/7384_2.png) [@97FormulaWS-6](https://forums.speedlife.net/u/97FormulaWS-6)\ **Post date:** [June 16, 2010, 8:34am UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/6 "2010-06-16T08:34:08Z")
Replaced the IAC this am… still doing it. No DTC codes. No vacuum leaks that I can find. Any other thoughts? MAP? Anyone have a scanner that will work on this truck? ---
**Author:** ![LUKE\_L](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/luke_l/32/7462_2.png) [@LUKE\_L](https://forums.speedlife.net/u/LUKE_L)\ **Post date:** [June 16, 2010, 9:03am UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/7 "2010-06-16T09:03:03Z")
We could run it to my old place. John has a scanner. ---
**Author:** ![llink78](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/llink78/32/8037_2.png) [@llink78](https://forums.speedlife.net/u/llink78)\ **Post date:** [June 16, 2010, 10:29am UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/8 "2010-06-16T10:29:06Z")
how did u check for a vacuum leak? just looking at hose, there could be a dry rotted/crack in one anywhere. u really shoud get some smoke for it ---
**Author:** ![97FormulaWS-6](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/97formulaws-6/32/7384_2.png) [@97FormulaWS-6](https://forums.speedlife.net/u/97FormulaWS-6)\ **Post date:** [June 16, 2010, 10:32am UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/9 "2010-06-16T10:32:13Z")
WD40 and carb-cleaner trick… had the fire extinguisher sitting 4’ away. LOL. Luke - My dad is bring out my laptop/scanner, I’m just not sure what OBDII network this truck has; mine can read anything but the CAN bus. ---
**Author:** ![97FormulaWS-6](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/97formulaws-6/32/7384_2.png) [@97FormulaWS-6](https://forums.speedlife.net/u/97FormulaWS-6)\ **Post date:** [June 16, 2010, 5:35pm UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/10 "2010-06-16T17:35:29Z")
Well, to conclude this thread… Found it tonight… turns out it was a vacuum leak that even spraying shit down didn’t find the first time… Spent an entire can of TB cleaner but I found it… Spent $230 on other parts ($110 of which for a battery which I needed anyway)… I had a cracked elbow on the PCV to Intake Manifold. Must have blown it off the intake the other day. Only issue is that it’s buried and impossible to see; you can only feel it. It’s under the cowl behind/under the back of the intake manifold. Taped it up tonight; gonna hit M&M and find a replacement as soon as I can. Thanks for the advice guys. ---
**Author:** ![llink78](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/llink78/32/8037_2.png) [@llink78](https://forums.speedlife.net/u/llink78)\ **Post date:** [June 16, 2010, 7:36pm UTC](https://forums.speedlife.net/t/04-grand-cherokee-idle-issue/156582/11 "2010-06-16T19:36:55Z")
glad it worked out for ya… i would of bet any money on a crack somewhere 🙂