SCARY!!!! Sudden Deceleration!!!! - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > JK Jeep Wrangler Forum > JK General Discussion Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 07-23-2012, 04:13 PM   #1
Newb
 
Join Date: May 2012
Posts: 14
SCARY!!!! Sudden Deceleration!!!!

Hi guys,

This is the 2nd time this has happened and scared the hell out of me both times! Coming down a hill in 6th gear doing about 110 - 120 km/h. I take my foot off the pedal and let the Jeep coast a bit then all of a sudden it takes a nose dive and feels and sounds like I dropped it into 4th!!!!!! This time it happened on a turn and if it was wet out or in the winter I know it wouldn't have ended the way it did! Scared the hell out of me since I had the wife and 5 month old with me. It only decel's for a few seconds and then it is fine again but that sudden movement can be really bad come winter! Wondering if anyone else has experienced this I haven't been able to find anything on any forum's.

2012 Jeep Wrangler unlimited Sahara Stock
Manual 6 speed
4000Km's

Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:16 PM   #2
Jeeper
 
JeepsInDeep's Avatar
 
Join Date: Apr 2012
Location: Greensboro, NC
Posts: 390
Why on God's green earth are you doing 110 in a Jeep with your wife and 5 month old in it?

But to answer your question, no ... I've never heard of another forum member having this issue. Most of us don't like to go fast in our Jeeps, we go 3 mph over rocks and in mud holes

__________________
JeepsInDeep is offline   Quote Quick Reply
Old 07-23-2012, 04:18 PM   #3
Jeeper
 
Malan35's Avatar
 
Join Date: Sep 2011
Location: Delray Beach, FL
Posts: 87
Quote:
Originally Posted by JeepsInDeep
Why on God's green earth are you doing 110 in a Jeep with your wife and 5 month old in it?

But to answer your question, no ... I've never heard of another forum member having this issue. Most of us don't like to go fast in our Jeeps, we go 3 mph over rocks and in mud holes
110 KM/H. Not MPH
Malan35 is offline   Quote Quick Reply
Old 07-23-2012, 04:19 PM   #4
Jeeper
 
ferninAZ's Avatar
 
Join Date: Feb 2012
Location: Sierra Vista, Arizona
Posts: 870
Quote:
Originally Posted by JeepsInDeep
Why on God's green earth are you doing 110 in a Jeep with your wife and 5 month old in it?

But to answer your question, no ... I've never heard of another forum member having this issue. Most of us don't like to go fast in our Jeeps, we go 3 mph over rocks and in mud holes
110 km per hour is not exactly fast.
ferninAZ is online now   Quote Quick Reply
Old 07-23-2012, 04:19 PM   #5
Jeeper
 
LVCapo's Avatar
 
Join Date: Apr 2012
Posts: 201
Quote:
Originally Posted by JeepsInDeep View Post
Why on God's green earth are you doing 110 in a Jeep with your wife and 5 month old in it?

But to answer your question, no ... I've never heard of another forum member having this issue. Most of us don't like to go fast in our Jeeps, we go 3 mph over rocks and in mud holes
110KM/H is about 63MPH.....
LVCapo is offline   Quote Quick Reply
Old 07-23-2012, 04:20 PM   #6
Newb
 
Join Date: May 2012
Posts: 14
Yes 110 KM/H That's what the speed limit is. I am not hoping anyone else has had this issue but I hope someone knows something about it. Not fun to have happen.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:20 PM   #7
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,347
If you let off the accelerator then the RPM's are going to drop and you have to down shift. Are you familiar with driving a manual?

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Suspension package deals available
Daniel_M is offline   Quote Quick Reply
Old 07-23-2012, 04:23 PM   #8
Jeeper
 
C.L.'s Avatar
 
Join Date: Mar 2011
Location: North NJ
Posts: 1,979
Did you hear the engine race when it decelerated? If yes, you have some funny business going on in your transmission that needs to be sorted ASAP.

Since you said it happened down hill and on a corner though, i'm betting the stability control is fighting you. The 2012's have some sort of yaw sensor or whatnot in them that tries to keep you in a straight line. Maybe you compressed the suspension enough, or dragged a tire a little and it thought you were skidding.
C.L. is offline   Quote Quick Reply
Old 07-23-2012, 04:24 PM   #9
Newb
 
Join Date: May 2012
Posts: 14
I drive a 6 speed F350, and I have had manuals my hole life this was nothing that should happen! The first time it happened i was just backing off the gas and it was honestly like I slammed it into 3rd.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:24 PM   #10
Jeeper
 
JeepsInDeep's Avatar
 
Join Date: Apr 2012
Location: Greensboro, NC
Posts: 390
Quote:
Originally Posted by Daniel_M View Post
If you let off the accelerator then the RPM's are going to drop and you have to down shift. Are you familiar with driving a manual?

-Dan
My Bad on the MPH mixup

And I think he's saying that his Transmission is auto-downshifting.
__________________
JeepsInDeep is offline   Quote Quick Reply
Old 07-23-2012, 04:26 PM   #11
Jeeper
 
snochick's Avatar
 
Join Date: Apr 2012
Location: Arizona
Posts: 1,113
Images: 2
Mine has done that at about 30-35 mph here on base. Engine stutters when it happens. It stutters on trail sometimes too. Haven't had it happen going anywhere over 50 but hubby said it has on him.

Dealer doesn't know bc we can't get it to duplicate when we want it to do it. Seems to happen most on exceptionally humid hot days. Never noticed it before monsoon season hit but that could be coincidence as I'd only had it a month before then. Still evaluating. I'm rarely on the hwy so I haven't been able to test much to see how to duplicate the issue.
__________________
Harley Quinn: 2011 JKU Bright Silver Rubicon (His)
Poison Ivy: 2012 JKU Gecko Pearl Sport (Mine)

Jeeps of Old: '89 White YJ (1rst Jeep), '01 TJ Yellow Sport, Mudbird: 2001 TJ Silver Sport (Miss this old girl, may she rest in peace)
snochick is offline   Quote Quick Reply
Old 07-23-2012, 04:27 PM   #12
ESP
Needs stuff..
 
ESP's Avatar
 
Join Date: Jun 2010
Location: NC
Posts: 11,393
Sounds like your ESC is engaging. Is your steering wheel straight? Have you lifted/aligned your jeep recently?
__________________
98 XJ 02 TJ 10 JK 13 JK

2013 JK - Lifted w/ 35s - Bilstein 5100s - Monster TB - Chopped Flares - Can't Keep It Clean
ESP is offline   Quote Quick Reply
Old 07-23-2012, 04:29 PM   #13
Newb
 
Join Date: May 2012
Posts: 14
Quote:
Originally Posted by C.L. View Post
Did you hear the engine race when it decelerated? If yes, you have some funny business going on in your transmission that needs to be sorted ASAP.

Since you said it happened down hill and on a corner though, i'm betting the stability control is fighting you. The 2012's have some sort of yaw sensor or whatnot in them that tries to keep you in a straight line. Maybe you compressed the suspension enough, or dragged a tire a little and it thought you were skidding.

Yes the engine raced when it happened.

It could be the stability control I guess. I didn't think i was that deep into the corner just starting to come into it but maybe this is the issue! I will bring it up with them. I think I have heard of some Silverados having this issue but I have only heard of automatics.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:30 PM   #14
Jeeper
 
snochick's Avatar
 
Join Date: Apr 2012
Location: Arizona
Posts: 1,113
Images: 2
It does downshift when it happens. At least mine does. And it's rough when it shifts back into the proper gear. All of it happens very quickly too.

I know what op is describing. It's kinda scary bc you're just driving along and it feels like someone hooks you with a boat anchor. Then it's over before u can register what just happened.
__________________
Harley Quinn: 2011 JKU Bright Silver Rubicon (His)
Poison Ivy: 2012 JKU Gecko Pearl Sport (Mine)

Jeeps of Old: '89 White YJ (1rst Jeep), '01 TJ Yellow Sport, Mudbird: 2001 TJ Silver Sport (Miss this old girl, may she rest in peace)
snochick is offline   Quote Quick Reply
Old 07-23-2012, 04:30 PM   #15
Jeeper
 
JeepsInDeep's Avatar
 
Join Date: Apr 2012
Location: Greensboro, NC
Posts: 390
Quote:
Originally Posted by snochick View Post
Mine has done that at about 30-35 mph here on base. Engine stutters when it happens. It stutters on trail sometimes too. Haven't had it happen going anywhere over 50 but hubby said it has on him.

Dealer doesn't know bc we can't get it to duplicate when we want it to do it. Seems to happen most on exceptionally humid hot days. Never noticed it before monsoon season hit but that could be coincidence as I'd only had it a month before then. Still evaluating. I'm rarely on the hwy so I haven't been able to test much to see how to duplicate the issue.
Funny you mention that ... I used to have a silverado and no more than 300 miles on it I started doing the same thing. I took it back 3 times and they finally figured out that the windshield wipers were sending a charge back to the PCM and overloading it. Not sure if it helps, but it's funny what electrical systems will do.
__________________
JeepsInDeep is offline   Quote Quick Reply
Old 07-23-2012, 04:31 PM   #16
Newb
 
Join Date: May 2012
Posts: 14
Quote:
Originally Posted by ESP View Post
Sounds like your ESC is engaging. Is your steering wheel straight? Have you lifted/aligned your jeep recently?
No my wheel would have been turned slightly so not straight. It is bone stock haven't lifted it yet or done anything to it.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:31 PM   #17
Jeeper
 
C.L.'s Avatar
 
Join Date: Mar 2011
Location: North NJ
Posts: 1,979
Quote:
Originally Posted by Daniel_M View Post
If you let off the accelerator then the RPM's are going to drop and you have to down shift. Are you familiar with driving a manual?

-Dan

He's not concerned with rpm drop; he's concerned about it decelerating sharply. In 6th, there is very little engine braking going on; something else is happening.
C.L. is offline   Quote Quick Reply
Old 07-23-2012, 04:31 PM   #18
Jeeper
 
JeepsInDeep's Avatar
 
Join Date: Apr 2012
Location: Greensboro, NC
Posts: 390
Quote:
Originally Posted by Yukonsavage View Post
Yes the engine raced when it happened.

It could be the stability control I guess. I didn't think i was that deep into the corner just starting to come into it but maybe this is the issue! I will bring it up with them. I think I have heard of some Silverados having this issue but I have only heard of automatics.
LoL ... see my comment above!
__________________
JeepsInDeep is offline   Quote Quick Reply
Old 07-23-2012, 04:33 PM   #19
Newb
 
Join Date: May 2012
Posts: 14
Quote:
Originally Posted by snochick View Post
It does downshift when it happens. At least mine does. And it's rough when it shifts back into the proper gear. All of it happens very quickly too.

I know what op is describing. It's kinda scary bc you're just driving along and it feels like someone hooks you with a boat anchor. Then it's over before u can register what just happened.
That's exactly what it feels like. I just cant figure out why the manual transmission would just randomly down shift when in gear and pick back up again.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:35 PM   #20
Jeeper
 
C.L.'s Avatar
 
Join Date: Mar 2011
Location: North NJ
Posts: 1,979
Quote:
Originally Posted by Yukonsavage View Post
Yes the engine raced when it happened.

It could be the stability control I guess. I didn't think i was that deep into the corner just starting to come into it but maybe this is the issue! I will bring it up with them. I think I have heard of some Silverados having this issue but I have only heard of automatics.
If it was firmly in 6th, and the clutch was out, there should have been NO way for the engine to rev up. Does the stick jump/shake? I would get that back to the dealer at this point. You're under warranty, and your transmission is doing something a manual shouldn't be able to do...
C.L. is offline   Quote Quick Reply
Old 07-23-2012, 04:36 PM   #21
Jeeper
 
JeepsInDeep's Avatar
 
Join Date: Apr 2012
Location: Greensboro, NC
Posts: 390
I'm actually with ESP on this ... your ESC is engaging when it's not supposed to be. So maybe you have a short somewhere that is confusing the computer into thinking that it needs to engage the ESC? That's what happened to my silverado ... kinda.
__________________
JeepsInDeep is offline   Quote Quick Reply
Old 07-23-2012, 04:37 PM   #22
Newb
 
Join Date: May 2012
Posts: 14
Quote:
Originally Posted by C.L. View Post
If it was firmly in 6th, and the clutch was out, there should have been NO way for the engine to rev up. Does the stick jump/shake? I would get that back to the dealer at this point. You're under warranty, and your transmission is doing something a manual shouldn't be able to do...
Yeah I am gonna take it in this week. I don't want the wife driving it like that. I was kinda prepared this time cause it was around the same place it happened the first time. Its a few hours away so the next time I will gopro it and see what it does. The clutch was out and my hand was on the stick so it was in 6th firmly.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:40 PM   #23
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,347
Quote:
Originally Posted by C.L. View Post
He's not concerned with rpm drop; he's concerned about it decelerating sharply. In 6th, there is very little engine braking going on; something else is happening.
Right. Merely trying to out rule the obvious. A lot of time it is the answer. If he was a noob to manual, it wouldn't be surprising.

Quote:
Originally Posted by C.L. View Post
If it was firmly in 6th, and the clutch was out, there should have been NO way for the engine to rev up. Does the stick jump/shake? I would get that back to the dealer at this point. You're under warranty, and your transmission is doing something a manual shouldn't be able to do...
I agree, if it is firmly in whatever gear you are in, it should in no way jump out of gear or feel like you are downshifting. Take it back for warranty work.

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Suspension package deals available
Daniel_M is offline   Quote Quick Reply
Old 07-23-2012, 04:42 PM   #24
Supporting Member Commercial Member

WF Supporting Member
 
Daniel_M's Avatar
 
Join Date: Nov 2011
Location: Arizoner
Posts: 2,347
I am surprised at how many 2012's have issues and need warranty work done. Between fires, ticking etc...It is alarming to me, initially. I digress though...

Back on topic

-Dan
__________________
-Dan, Owner
RockRaider4x4 - PM me for a quote
Free shipping on most items
Suspension package deals available
Daniel_M is offline   Quote Quick Reply
Old 07-23-2012, 04:46 PM   #25
Newb
 
Join Date: May 2012
Posts: 14
Quote:
Originally Posted by Daniel_M View Post
I am surprised at how many 2012's have issues and need warranty work done. Between fires, ticking etc...It is alarming to me, initially. I digress though...

Back on topic

-Dan
Yeah its a little disheartening when you read all the forums I still love the jeep though. I am also having the issue of the A/C shutting off randomly for 4 seconds and then firing back up again. Dont think that will be related to the tranny issue.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 04:48 PM   #26
Jeeper
 
JeepsInDeep's Avatar
 
Join Date: Apr 2012
Location: Greensboro, NC
Posts: 390
Quote:
Originally Posted by Yukonsavage View Post
Yeah its a little disheartening when you read all the forums I still love the jeep though. I am also having the issue of the A/C shutting off randomly for 4 seconds and then firing back up again. Dont think that will be related to the tranny issue.
Don't be so sure ... it sounds like you have a short somewhere TBH. And if that's the case ... you're getting a new jeep my friend!
__________________
JeepsInDeep is offline   Quote Quick Reply
Old 07-23-2012, 05:01 PM   #27
Jeeper
 
Jeeperz Creeperz's Avatar
 
Join Date: May 2012
Location: Pensacola, Fl
Posts: 899
I wonder if the techs can see if stability or traction control initialized and when? The hard deceleration could be the braking system kicking in.
Jeeperz Creeperz is offline   Quote Quick Reply
Old 07-23-2012, 05:06 PM   #28
ESP
Needs stuff..
 
ESP's Avatar
 
Join Date: Jun 2010
Location: NC
Posts: 11,393
Quote:
Originally Posted by Yukonsavage View Post
No my wheel would have been turned slightly so not straight. It is bone stock haven't lifted it yet or done anything to it.
ESC engaging when it shouldn't is more common after lifting and the sensors have either been damaged or it results from the alignment being off. Both can trigger the program to initiate and the jeep will do exactly what you described. This can take place with a stock jeep however it is more rare. You should have it looked at as one of the wheel sensors may be triggering falsely and telling the computer your loosing traction when you are not. The computer will attempt to brake the wheel its being told is not biting and will apply the brakes to one or more of them.

This can be annoying but even more so dangerous if it triggers while your doing the speeds you mentioned.
__________________
98 XJ 02 TJ 10 JK 13 JK

2013 JK - Lifted w/ 35s - Bilstein 5100s - Monster TB - Chopped Flares - Can't Keep It Clean
ESP is offline   Quote Quick Reply
Old 07-23-2012, 05:07 PM   #29
Newb
 
Join Date: May 2012
Posts: 14
Quote:
Originally Posted by Jeeperz Creeperz View Post
I wonder if the techs can see if stability or traction control initialized and when? The hard deceleration could be the braking system kicking in.
Yeah that very well could be the issue. It just throws me off cause it sounded like the engine was racing. Not like a break locking up. I will ask them if they can see when it happens and if it records it at all.
Yukonsavage is offline   Quote Quick Reply
Old 07-23-2012, 05:10 PM   #30
kik
Jeeper
 
kik's Avatar
 
Join Date: Dec 2008
Posts: 4,341
Images: 1
Quote:
Originally Posted by snochick View Post
It does downshift when it happens. At least mine does. And it's rough when it shifts back into the proper gear. All of it happens very quickly too.

I know what op is describing. It's kinda scary bc you're just driving along and it feels like someone hooks you with a boat anchor. Then it's over before u can register what just happened.
I understand what you're saying. He indicated that he has a manual 6spd. There is no way his trans. can do anything but stay in 6th unless he pushes in the clutch and down shifts. An auto is obviously going to. I think ESP might be on to something.

kik is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



logo carid shop wrangler parts carid fender flares custom wheels store avs deflectors at carid
» Rates
Get low rates on auto insurance in Canada!

» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 12:48 AM.



Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC.
Wranglerforum.com is not in any way associated with the Chrysler Motors LLC