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BiTurboS4 05-05-2012 10:38 AM

Slight Pulsing Feeling
06 Laredo 3.7L AWD

When just driving around which is up and down a lot. If you are in OD and start to go up a grade, sometimes you can feel a very light, but noticable, pulse (like a really quick downshift/upshift, repeatedly).. not violent, but its almost like the TCM can't decide to downshift to get up the hill, or to stay in OD.

Any idea why and how to fix this?

Truck has 88k and goes in for trans fluid change next week. Both diffs were done a few weeks ago.

Dont want to make multiple threads...

The other issue, when its REALLY hot out and you've been driving for awhile and come to a stop. IF you let the Jeep idle for a few minutes, it will randomly and not consistantly idle down and jerk and then idle back up where its suppose to. it will drop down to 600 or so RPM's, shake for a second and go back to normal. I dont think its stalled on her yet.

Plugs were just done about 5k ago, give or take.

BiTurboS4 05-05-2012 10:46 AM

Re: Slight Pulsing Feeling
didn't look hare enough.. found my answer to the first question down the page... second one though still bugs me.

Bleeding Blue 05-05-2012 10:49 AM

Re: Slight Pulsing Feeling
What answer did you find? I know many of us have the same problem and havent found a solution

BiTurboS4 05-05-2012 10:57 AM

Re: Slight Pulsing Feeling
no real solution.. just the thread about it being common..

since we didn't buy this new, IDK if its osmething that's just going to happen due to the 3.7 being under powered.. or if there actually IS something wrong.

If guys are taking it to the dealerships and they are saying there is nothing coming up as being wrong with it. Even when they test drive it. What can we really say?

We got an aftermarket warranty that covers the drivetrain. I just dont think they are going to replace the torque converter or the trans because we think its the problem.

Bleeding Blue 05-05-2012 11:03 AM

Re: Slight Pulsing Feeling
I dont think it is the trans, mine literally exploded about 5k ago (including the torque converter) and it is still there....

BiTurboS4 05-05-2012 11:14 AM

Re: Slight Pulsing Feeling
Mine doesn't do anything like mentioned in the thread (harsh jerking while driving down the highway).. Mine is more going from flat road to an incline and giving it gas while in OD but not enough to kick it down.. it seems to not know if it should kick down or stay in OD. its a light flutter so to speak

Madanio24 05-05-2012 03:14 PM

Re: Slight Pulsing Feeling
That is one of the symptoms of mine. I hardly doubt the answer is that the cars underpowered. After all it never used to happen before. The dealership actually felt my problem and are investigating further. He thinks it's a problem with the clutch in the torque converter not opening correctly.

FlyinRyan 05-05-2012 03:46 PM

Re: Slight Pulsing Feeling
Did any of you replace the TPS? I thought Madanio did, but can't remember.

I am curious about this problem.

BiTurboS4 05-05-2012 03:51 PM

Re: Slight Pulsing Feeling
Someone did but it didn't fix the problem.

It's done it the whole time we've owned it. Please lmk what they find out. Having an aftermarket warranty I'll get it fixed.

Madanio24 05-05-2012 06:01 PM

Re: Slight Pulsing Feeling

Originally Posted by FlyinRyan (Post 625081)
Did any of you replace the TPS? I thought Madanio did, but can't remember.

I am curious about this problem.

Yep I replaced the Tps with oem one. The tech said the transfer case is locking up and opening he told me to throw in oem spark plugs and bring it back to him and he's going to look at it for a few days. Will post back because this seems like a fairly common problem. The only thing that helped a little bit was the update on the PCM definitely shifts a lot better :thumbsup:

Madanio24 05-05-2012 06:03 PM

Re: Slight Pulsing Feeling
The tech diffinatley felt the pulsing driving on his own in the car and doesn't think it's normal at all. Also asked him to use star scan tool to set my headlights to export mode! Super excited lol.

Maintainer 05-12-2012 05:32 PM

Re: Slight Pulsing Feeling
I also have this problem with our '05 3.7 Rocky Mtn edition.
I changed the TPS and now it's throwing a "P0122" code (low voltage to TPS).
I've been running E3 spark plugs and changed wires about 15k miles ago.
I can hear & feel a grinding when it hesitates. It makes me think that there is slippage in the trans. because I smelled the trans fluid and it has a burnt smell (witnessed by mechanic friend also).
Also had trans & converter flushed about 1 year ago.
I have made a contact with a Chrysler tech and he is going to look at it within the next couple weeks....hopefully all my troubleshooting will have put this in a repairable direction.

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