Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   2014+ Jeep Grand Cherokee Ecodiesel 3.0 (http://www.jeepgarage.org/f222/)
-   -   new to forum with 2014 GC eco diesel that has an issue (http://www.jeepgarage.org/f222/new-to-forum-with-2014-gc-eco-diesel-that-has-an-issue-76456.html)

nikkstokes 06-23-2014 02:30 PM

new to forum with 2014 GC eco diesel that has an issue
 
hello all,

first post here but I've been getting advice on this forum for years. so first off thank you.

recently purchased a new GC ecodiesel and have a problems with a pretty bad shudder and any advice would be appreciated.

I have 4,000 miles on it and this issue mostly happens upon start up while traveling at approx. 50-65 miles per hour. it seems to happen mostly in 7th and 8th gear and if you back off the throttle is remains, but if you nail the gas it seems to go away. i just took it to the dealer and the software is up to date. they reset the learnables in TCM and said it takes the transmission between 4-6 thousand miles to 'break in'. I asked them about the valve body and they said it would come up in their comp which it didn't. the shudder has remained and seems to happen everyday now.

any ideas or advice would be appreciated.

KONE-DAWG 06-23-2014 03:38 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
Out of balanced tires can cause similar problems
assuming some the shuddering is transmitted through the steering wheel

nikkstokes 06-24-2014 12:24 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
I don't feel it in the steering wheel, so I don't really think it's the tires. I'll get them rotated and balanced next oil change.

The shudder kinda feels like it's not getting enough fuel, and only happens early in the drive and mostly at highway speeds

KONE-DAWG 06-24-2014 12:37 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
clogged fuel filter or faulty fuel pump? most noticable at speed and especially climbing

ExcursionDiesel 06-24-2014 12:57 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
You have what is refered to as "fishbites" on this forum.

Let me guess....it does it nearly every time you first start the vehicle and shift through all gears. It happens in 5-6, 6-7, 7-8 shifts. It shudders more if going up a hill at 2400 rpm or less (more torque at low rpm = more shudder). Downshifting stops it but shifting higher may shudder in the next gear. Once each gear has been engaged one time, the problem is gone...until you shutdown and then drive it again after 20-30 minutes.

Mine does this and I paddle downshift then upshift at 2500 rpm when it occurs. It may not occur on flat ground under light throttle but more often now it does.

I have a theory that the valvebody is losing prime and has air bubbles that purge with use. The shudder is the valve body pressurw oscillating due to unstable fluud dynamics from air entrapement. IMO a new valve body is required is to fix it.

My second theory is that the torque converter pulse width modulation is causing the shudder. It uses PWM to create a ramped engagement of the lockup clutch. This is supposed to soften the engagement but it may cause the clutch to chatter and feel like pulses of torque. Probably a replacement needed there.

Based on your report that all the latest flashes and a relearn didn't fix it, I have a feeling that a mechanical repair is needed. I forced a relearn by removing fuse F60 for 30 minutes. It helped but the fishbites came back after a few weeks.

I think a Star case needs to be opened so we can have a documented fix and dealers won't be prone to "experiment" on our vehicles and keep them in the shop for weeks. There are some documented repairs on furum member's transmissions where a valve body swap fixed these issues.

nikkstokes 06-25-2014 08:29 AM

Re: new to forum with 2014 GC eco diesel that has an issue
 
you nailed it. I'm assuming you have had this same issue? did it get resolved?

the shudder would happen once a week or so, and now it seem more frequent.

UnsungChip 06-25-2014 09:12 AM

Re: new to forum with 2014 GC eco diesel that has an issue
 
I have the exact same issue. Haven't spoke to the dealer about it yet.

ExcursionDiesel 06-25-2014 09:20 AM

Re: new to forum with 2014 GC eco diesel that has an issue
 
I plan on taking mine in for service in the next month and will have the shudder documented. My problem is that I need my vehicle every day so its a hassle.

lectricman 06-26-2014 04:49 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
Took mine in today for the exact same problem. Dealer is claiming that a TSB needs to be done. Problem is that their computer is down so they are waiting for it to come back up. In a rental right now. The best way I can describe how it feels is if the road turned into a washboard but the tires aren't bouncing around.

ExcursionDiesel 06-26-2014 06:37 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
It does feel a bit like running over widely spaced rumble strips on the edge of the road....but the road is smooth. Let us know what happens with your Jeep's service.

Benn0 06-26-2014 07:53 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
Someone in the Oz forum had this problem, a shudder around 100kph that felt like driving over a cattle grid. The fix was to replace the dpf and sensor:
http://www.jeepgarage.org/f190/2012-...tml#post982253

ExcursionDiesel 06-26-2014 08:22 PM

Re: new to forum with 2014 GC eco diesel that has an issue
 
Interesting read on the Oz shudder. I wonder how the DPF would cause a shudder like this? Was the ECU reacting wierd to a bad sensor?


All times are GMT -5. The time now is 12:38 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community