Jeep Enthusiast Forums banner

Rapid RPM drop when manually shifting and stopping

768 views 6 replies 2 participants last post by  jeep1987 
#1 ·
Most of the time when I shift from drive to park the RPM will go up a little and then quickly drop down to 100-200, you can hear the engine struggle to stay on and it has stalled twice. Sometimes it does it from reverse to drive. And it often does the same thing when I stop at a light and it makes the final downshift.

Any ideas what it could be? I had a smoke test done and they found no leaks, but I'm still thinking it a vacuum leak somewhere. The IAC, TPS, and CPS are all about 6 months old and Mopar, throttle body cleaned last year, spark plugs changed last year. I've had one person say it's the torque converter sticking.
 
#2 ·
what does it do when shifting back into park? and how does it run when in park?

Edit: Completely misread your first sentence >.<. Same question though, what does it do when shifting from drive to neutral, and does it idle fine in drive/neutral? Also how does it run when you first start it in park.
 
#3 ·
The last couple days I messed around shifting it between gears. Shifting from neutral to drive, drive to neutral, did nothing. Shifting from Park to drive, drive to park would cause it to jump a tiny bit and fall down to 400ish, and I can hear the engine bog a little.

A while ago the rpm dropped a lot while stopped at a light, this happened on two separate occasions but hasn't happened again for a long time.

What usually causes the RPM drop is stopping fast and when it makes the last downshift, and pulling up somewhere and shifting to park. If I pull up, and wait like 5 or 10 seconds it won't do it as bad, but if I pull up and shift to park right when I stop, it will usually drop pretty fast and either stall or come close to it.

When I stop it feels like it's holding onto the gear, then I can feel it let go, and then the RPM drops.
 
#4 ·
If there's no issue shifting from drive to neutral after coming to a stop, I don't think its the torque converter. N and P are the same thing, park just engages the prawl on the gear to lock up the trans. My money is on something electrical still. After it drops in rpm, does it return to normal?
 
#7 ·
I've been trying to remember to shift into Neutral instead of park when I stop. So far it only dropped a little once when I went to neutral instead of park, every other time it hasn't dropped at all. It's still dropping RPM fast when I shift to park from drive or drive to park, a few minutes ago when I went from Park to Drive it dropped really fast to 200 rpm.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top