Sudden jolt - shudder experienced

Discussion in 'Gen 5 Prius Main Forum' started by Tekz, Jan 17, 2026 at 7:50 AM.

  1. Tekz

    Tekz New Member

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    I have a PHEV and when in HV mode parked on a standstill while shifter is in P, after the ICE engine shuts off, I feel a shudder from the engine that I experience the car suddenly “jolts” forward (not by much but very noticeable). Feel that the transition isn’t smooth and seamless…has anyone else experienced this with PHEV/HEV Prius?
     
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  2. VelvetFoot

    VelvetFoot Active Member

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    I haven't looked it up, but I recall a Car Nut (?) video where he said that was normal.
     
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  3. Tekz

    Tekz New Member

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    Gotcha…I also have a CRV hybrid but that’s very seamless when the ICE shuts off you barely feel or notice anything while parked. Guess the Toyota hybrids aren’t as refined oh well
     
  4. VelvetFoot

    VelvetFoot Active Member

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    I found the video earlier where he says it moves a little if you don’t have it in park when it starts up. So I imagine the same thing would happen if it shuts down.
     
  5. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    Sometimes, the shutoff when in P will indeed shake the car substantially, but I have never felt that it lurched. The shutoff when in D like coming to a stop light is many times not felt. When transitioning from EV to HV mode ( the EV mode charge switches to ----), the car also shakes considerably.. I track EV miles separate from HV mode (only drive HV when EV charge is ----), so that shake and the sudden roar of the engine designate the end of EV mode travel and remind me to look at my "Trip Meter A" which is displayed while I drive in EV mode.
     
  6. BiomedO1

    BiomedO1 Senior Member

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    Unfortunately; 'your feeling' can't really be quantified or measured here - so we don't really have a point of reference. My 'feeling' is that my EV to HV and back transitions are smooth and quiet 'most of the time'. The occasions when your in stop n go traffic where transitions aren't smooth; ie. accelerating in EV, when the ICE kicks-on because the pack is too low. That harsh transition is few and far between for me. I've learned to back-off the accelerator pedal when that happens and that will quite down the 'jolt' before getting back on the pedal. If you keep pressing hard on the pedal during the transition, you can snap a motor mount, IMHO and the switch-over may seems harsher.

    You should test drive another car to make a comparison, or go over it with a dealership mechanic in the passenger seat.

    Good Luck......
     
  7. PickyAudioGuy

    PickyAudioGuy Junior Member

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    I had a 2010 Prius and was washing it on a cold night in a high pressure wash bay. It was in "ready" with no ICE running with the heater on. I was outside washing when the ICE kicked on and I remember how I jumped because the car rolled forward until it took the play out of the parking pawl. I thing this is normal based on the design of the transmission.
     
  8. Trollbait

    Trollbait It's a D&D thing

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    Their is a clutch disconnecting the engine from the wheels in the Honda system. It is only engaged at higher speeds. While it provides that better refinement, there is a bit of an efficiency penalty when it is running in series mode.

    The 2005 Prius always seemed to have more such play in Park than other cars. It put me in the habit of always using the parking brake.
     
  9. VelvetFoot

    VelvetFoot Active Member

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    This is the video I was thinking of. At 9:49, if the link doesn't work out.

     
  10. VelvetFoot

    VelvetFoot Active Member

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    The automatic electric parking brake on the Gen5 is nice. Until it fails, lol.
     
  11. Trollbait

    Trollbait It's a D&D thing

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    When does it engage? When shifted to park, or at shutdown?
     
  12. PriusCamper

    PriusCamper Senior Member

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    Lol... This is the nature of atkinson engine. Can't believe that we're now eleven comments in and no one has explained it yet? Here's an explanation on PriusChat from 19 years ago that you could of found way quicker by using a search engine than thinking all the dummies commenting on here are going to give you accurate info:

    "This is common to all Prii (at times). Your Internal Combustion Engine (ICE) runs an "Atkinson Cycle" which means that the intake valves are open for the first portion of each compression stroke (one of the unique aspects of a Prius). This puts some unburned fuel vapors back into the intake manifold (there is actually an activated carbon chamber that is there to store these vapors so that they do not get into the atmosphere). The ICE is shut down by turning off the fuel supply, but can continue to run (roughly) for a moment on these unburned vapors. Spark is maintained during this interval to ensure that the vapors are eliminated. No harm is being done to the vehicle when this occurs, but the roughness can be noticeable.Rough engine shut down | PriusChat
     
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  13. VelvetFoot

    VelvetFoot Active Member

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  14. VelvetFoot

    VelvetFoot Active Member

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    Perhaps I don't notice it because I'm in EV mode when turning off the car.

    dummies, eh?
     
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  15. Trollbait

    Trollbait It's a D&D thing

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    With more time driven in EV mode, noise and jolts from the engine could become more noticeable.
     
  16. Gokhan

    Gokhan Senior Member

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    This is perfectly normal. It happens occasionally in my Gen 4 PHEV. While the Prius electric planetary gear system is very good, it cannot break Newton’s third law of physics, and occasionally you will feel a recoil, especially when parked. To minimize recoil, when I drive, I switch to HEV mode by pushing the button at 21 mph on the speedometer (19 mph actual) while pressing the accelerator gently.