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Unread 12-08-2011, 06:27 PM   #1
BC Jeep
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Important jk engine idle repair

Hi All!

I have an 08 six speed JK 4 Door that has been ABSOLUTELY HORRIBLE for low speed take off and stalling when backing the vehicle or pulling a load.

Ive had it to the dealer under warranty several times and each time, "previously" they have either said that they couldn't duplicate my issue OR replaced something that FAILED to fix the issue.

My Warranty runs out in Jan SO,,,,,, I have to get this issue solved!!

I did a DETAILED DRIVE with the service manager and made him drive the Jeep.. BAM!! FIRST time he let the clutch out and start rolling,,, the Jeep STALLED and died.. After NUMEROUS stalls,, He agreed that there was an issue that needed to be FIXED!!

They replaced the Cam sensor. NOT FIXED! Today,, they call and said that the PCV Valve was the issue.

WHAT????????????????

They hooked the Jeep up to a real time driving Diagnostic Monitor and found that Throttle Body to be causing the issue. When they contacted JEEP Tech,, they were referred to a TSB for a different KNOWN issue.

NO BULL! They found a Technical Service Bulletin that stated that the WRONG/Defective PCV Valve could cause the issue!

They said that the NEW PCV Valve made the engine run SIGNIFICANTLY Better! There Still working on an AC Issue and I have to wait till thats fixed to see if the PCV fixed the issue.
More to come and I will add the TSB data to the post and all and any amplifying info that I find.

If your JK stalls easily or has a tough time starting off pulling a LOAD when start from a dead stop,, STAY TUNED!!

Bill

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Unread 12-08-2011, 08:31 PM   #2
tavic
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No issues here but Subscribed
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Unread 12-09-2011, 06:40 AM   #3
krutj
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Interesting...subscribed
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Unread 12-10-2011, 07:47 AM   #4
meon2wheels
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If I could fix one thing on the JK, this would be it! My I-6 258 CJ pulls nicely from idle while my '11 JK 6 speed will either flat stall, or sputter sub-idle for several seconds before dying. I know revving more during starts works, just not my driving style. Interested how this pans out for you.
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Unread 12-10-2011, 09:33 AM   #5
BC Jeep
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Quote:
Originally Posted by meon2wheels View Post
If I could fix one thing on the JK, this would be it! My I-6 258 CJ pulls nicely from idle while my '11 JK 6 speed will either flat stall, or sputter sub-idle for several seconds before dying. I know revving more during starts works, just not my driving style. Interested how this pans out for you.
WELL,,,,,,,,,,,,,,,,,,,,,,,,, AFTER THREE YEARS of hating my JK's inability to pull off from a stop,,,, All I can say after I picked it up an hour ago is AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH H

IT IS SOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO much better. I tried to stall it and it didn't stall.

A damn PCV caused all those issues. I also got 24.3 MPG on the 40 min drive back home. That about 2 MPG better that I usually get on the highway.

I wasn't able to speak with the service manager because the service department was closed on Saturday.

YES,,,,, THAT WAS THE ISSUE and I AM SO GLAD its resolved!!

The new PCV Part number is: 4648973AD (corrected number)

I will speak to the Service manager on Monday and get the info on the TSB. Its deals with Throttle Body repair.

Bill
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Unread 12-10-2011, 10:44 AM   #6
meon2wheels
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Cool! Let us know how the discussion with the service manager goes. Thanks for the PN too.
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Unread 12-10-2011, 11:36 AM   #7
nyrangersfan19
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Quote:
Originally Posted by BC Jeep View Post
The new PCV Part number is: 448973AD
Called to get availability on that part #. They told me its a digit short.
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Unread 12-10-2011, 11:57 AM   #8
Mopar Fan
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Quote:
Originally Posted by nyrangersfan19 View Post
called to get availability on that part #. They told me its a digit short.
4648973ad
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Unread 12-10-2011, 12:58 PM   #9
BC Jeep
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Thanks for the back up. I went ahead and corrected the number in my thread.
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Unread 12-10-2011, 09:37 PM   #10
CGT2358
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I notice that it's difficult to maintain or adjust the throttle when releasing the clutch in the JK. Most of the time it's either a very slow start with little gas to avoid the stall or the computer jacks the RPMS up to 1500. Do you feel as though you have more control of the RPMS on the start? I may be next in line to have this done...
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Unread 12-11-2011, 08:23 AM   #11
tennistom1
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Quote:
Originally Posted by BC Jeep View Post
A damn PCV caused all those issues. I also got 24.3 MPG on the 40 min drive back home. That about 2 MPG better that I usually get on the highway.

The new PCV Part number is: 4648973AD (corrected number)
Congrats on resolving your issue. I have an 2009 but no stalling problem. 24.3 MPG is a SIGNIFICANT increase! I've seen 21 at best and average 14-17 depending. Wondering if changing PCV's would increase MPG? If so, that would be a great mod.
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Unread 12-11-2011, 08:37 AM   #12
BC Jeep
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My problem was " When I would let the clutch out and throttle up to keep the engine from loosing RPM, the power at low throttle angles wasn't there and the RPMs would fall to a MAGIC RPM and the engine would just run rough and then shutter and then STALL. "

For what ever reason, it was really bad if you tried to reverse up a slight incline.. Unless you hit the throttle hard and then jerked the JK to get it moving, it would stall each time.

After the PCV change,,, I can just about let the clutch out WITHOUT any accelerator and it will move out without stalling. Its like a completly different Jeep now!

When the Service Manager told me it was a PCV Issue causing the problem,, I thought he was being funny..

After going over and over the issue in my head, it kind of makes sense that if the PCV was allowing in too much air, The Throttle By Wire Throttle Body, Throttle blade will be more SHUT that it would be normally (with the correctly calibrated PCV) When its closed that much it has a difficult time managing the air flow at low engine speeds and low load situations.

BC
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Unread 12-11-2011, 08:49 AM   #13
BC Jeep
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Quote:
Originally Posted by tennistom1 View Post
Congrats on resolving your issue. I have an 2009 but no stalling problem. 24.3 MPG is a SIGNIFICANT increase! I've seen 21 at best and average 14-17 depending. Wondering if changing PCV's would increase MPG? If so, that would be a great mod.


tennistom1

If you don't have the stalling issue,, changing the PCV will not have (or) should not have any effect on your engine or engine efficiency.

The air flow thru my engine at part throttle was so screwed up that it was causing engine power issues at low throttle angles. Just like the service manager told me over the phone. Your engine even sounds different when it starts and idles!

If an engine has the stalling issue, caused by the wrong or defective PCV, the correct PCV will make a significant difference.

BC
It DOES sound better!
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Unread 12-18-2011, 07:37 AM   #14
CGT2358
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A couple of days ago I changed my PCV out for the recommended per above and it does make a difference. I've noticed more control over the RPMs when releasing the clutch and the idle doesn't choke out as it did before. As for the gas mileage, I haven't been on the highway where I would notice a significant improvement. Driving locally it has improved a couple tenths of a mile but I'm not sure if that's related. All in all, it's a very cheap correction to a very annoying problem.
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Unread 12-18-2011, 08:09 AM   #15
rubizen
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1. Recently I have been having trouble with rough idle. I remembered your post about rough idle and bought a
PCV valve at the dealer. I have yet to install it but I hope it helps.

2. BC Jeep, have you had any problems with your '08 burning excessive oil? I have read on this forum that a
bad PCV valve can cause excessive oil burning. I burn 1qt./3k miles. Not excessive in Chryslers opinion but
I still wish it was less.

I'm hoping a new PCV valve will help both my problems.
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