1. Attachments are working again! Check out this thread for more details and to report any other bugs.

High engine idle speed

Discussion in 'Gen 3 Prius Technical Discussion' started by Chad's Dad, Jan 17, 2011.

  1. Chad's Dad

    Chad's Dad Junior Member

    Joined:
    Jun 22, 2010
    35
    10
    0
    Location:
    Austintown, OH
    Vehicle:
    2017 Prius
    Model:
    Three
    Had a first-time issue with my car today and wondered if anybody has had a similar issue. Background, 2010 II bought in June, just short of 15K miles, never had any kind of mechanical issue.

    While en route to work this morning, I was about halfway into my 15 minute drive to work, when I noticed my engine was idling very high, I would guess 2500 rpms. It started doing it while I was driving around 35 MPH, then continued doing it while I stopped at a traffic light, and continued when I continued driving to a speed around 50 MPH. The high idle while stopped was not transferred to the wheels, so it was not a safety issue as it would be in other cars.

    When I got back up to 50, curious to try something, I hit the ECO mode button and the car returned to normal. I took ECO back off and the car was still fine. I had no further problems.

    I would point out that this morning was about the coldest temp that the car has expereinced. Outside temp ranged from 7 to 10 degrees.

    I'll mark it down to a "crazy with the cold" moment and will keep an eye on it. I need to make my 15,000 service appointment and will mention it to them. Just curious if anybody else has run across something like that.
     
  2. GrumpyCabbie

    GrumpyCabbie Senior Member

    Joined:
    Dec 14, 2009
    6,722
    2,120
    45
    Location:
    North Yorkshire, UK
    Vehicle:
    2010 Prius
    Model:
    III
    Sounds about right to me for the cold conditions you describe.

    You might also get similar things happen in hot weather where the battery fan will blow hard sometimes (sounds like a hair dryer).

    You could tell the service department when you're in so they can check for any dodgy codes etc.
     
  3. qbee42

    qbee42 My other car is a boat

    Joined:
    Mar 2, 2006
    18,058
    3,073
    7
    Location:
    Northern Michigan
    Vehicle:
    2006 Prius
    As you point out, engine speed is not directly related to wheel speed. In your case this morning, the engine was working harder to keep your car warm. Switching to ECO told it to not try so hard.

    Tom
     
  4. Chad's Dad

    Chad's Dad Junior Member

    Joined:
    Jun 22, 2010
    35
    10
    0
    Location:
    Austintown, OH
    Vehicle:
    2017 Prius
    Model:
    Three
    The idle speed would be a safety issue in any car with a driveshaft, but not Prius.

    I will have them check the codes out, thanks.
     
  5. David Beale

    David Beale Senior Member

    Joined:
    Jul 24, 2006
    5,963
    1,979
    0
    Location:
    Edmonton Alberta
    Vehicle:
    2012 Prius
    You won't have a code unless you have a light. I wouldn't bother. It's normal behavior (that's Toyota Tech speak ;) ). It can also rev. if the battery is "fully" charged, as it will try to dump the excess charge by spinning the engine with the electric motor. Probably not what happened to you this time, but just for info.

    Pearl will "idle" in the cold at over 1200 RPM, trying to keep warm. I think of it as "shivering". A GII but they are basically the same as the GIII.
     
  6. Chad's Dad

    Chad's Dad Junior Member

    Joined:
    Jun 22, 2010
    35
    10
    0
    Location:
    Austintown, OH
    Vehicle:
    2017 Prius
    Model:
    Three
    When I first noticed the engine noise, the first thing that I did was to look to see if I had accidentally bumped the shifter to B.
     
  7. tumbleweed

    tumbleweed Senior Member

    Joined:
    Oct 3, 2005
    4,067
    687
    0
    Location:
    Eastern Oregon
    Vehicle:
    2010 Prius
    Model:
    V
    I would agree that this is most likely normal cold weather behavior. Could the engine speed have been a bit lower than you estimated? Mine usually runs about 1250 or so when it's cold.
     
  8. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,480
    38,108
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    We had racing engine at idle with our previous 06 civic hybrid, a few times over maybe a month period. Very disconcerting: pull up to a red light, foot on brake, and rpm shot up to over 3000. Shift into neutral and it would jump another 4~5 100 rpm. This is with fully warmed up engine, just above freezing temps. Suspected buggy software, but not really sure.
     
  9. hbark

    hbark Junior Member

    Joined:
    May 9, 2004
    56
    3
    0
    Location:
    Bucks County, PA
    Vehicle:
    2017 Prius
    Model:
    Two
    I had the exact same thing happen to me this morning. It was 15 degrees out at the time. As someone else mentioned, the high idle speed didn't seem to transfer to the wheels at all. I'm due for an oil change in the next week or so, so I'll have them check it out.
     
  10. HTMLSpinnr

    HTMLSpinnr Super Moderator
    Staff Member

    Joined:
    Dec 8, 2003
    5,339
    917
    251
    Location:
    Surprise, AZ (Phoenix)
    Vehicle:
    2018 Tesla Model 3
    Model:
    N/A
    Cold start idle is 1300rpm in most conditions, and 1000rpm once warmed up (per my ScanGauge). I've never heard it "idle" higher, but we don't see temps as cold as you've described. Only once has my car been in temps that cold, and I never observed higher RPMs - granted it was in Eco mode the whole time.
     
  11. Jim E.

    Jim E. Junior Member

    Joined:
    Dec 2, 2010
    48
    3
    0
    Location:
    Eagle Lake, MN
    Vehicle:
    2010 Prius
    Model:
    II
    I've noticed this a couple times during cold mornings (-10F or below) if I stop for coffee midway during my short 3.5-mile 30mph commute. (Yes, I do ride my bike when I can :)) The ICE is "racing" when I pull into the Clark station, but when the car rolls to a halt the engine speed gradually reduces to "idle." I use 100% grill block, not that it makes much difference during my slow short commute. (ScanGuage-II arrives next week sometime.) I just figured the engine was working harder to heat itself or heat the cabin, & that I was observing a Prius cold-climate idiosyncrasy. I was not running Defrost or Max heat when it occurred. Climate control was set to 70F. I do not run Eco when it's this cold. I honestly didn't think much about it; I wasn't even troubled enough to call my dealer (EDIT: my car dealer), although I am glad the OP started a thread so I know I'm not the only one :)
     
  12. twittel

    twittel Senior Member

    Joined:
    Jul 7, 2010
    1,605
    148
    0
    Location:
    Mt. Pleasant, SC
    Vehicle:
    2010 Prius
    Model:
    III
    I wish Toyota would include a tachometer which would take a lot of the guesswork out engine idling. Some of this discussion reinforces my decision to only operate in the ECO, but I'm just an old fuddy-duddy.

    Happy Motoring,

    Tom
     
  13. Flaninacupboard

    Flaninacupboard Senior Member

    Joined:
    Apr 25, 2010
    1,297
    213
    0
    Location:
    Midlands - UK
    Vehicle:
    2010 Prius
    Model:
    N/A
    I wish there was a Super Eco mode, that didn't increase engine speed or run the engine just for cabin heat at all. at the moment i keep turning the climate control off when i know i am going to stop or go very slowly. i'll wait for the heat.
     
  14. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

    Joined:
    Oct 28, 2010
    7,669
    6,485
    0
    Location:
    Redneck Riviera (Gulf South)
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    Same here.
    A "user programmable" ECO mode would be a plus. It doesn't get all that cold here, so I find myself just leaving the HVAC off when I'm on short trips.
    I also wish the ICE could be shut down (without powering off) while the vehicle is in warm-up mode, but not moving. I currently have a gate that I have to manually unlock/drive through/re-lock, and then there's a stop light 200-feet beyond that.
    I've actually measured an increase in tank MPG by shutting down the car while at both stops to aviod the ICE running at zero MPH.

    I always drive with the car in ECO---and It's a very small savings, but still measureable.

    Oh well....:cool:
     
  15. Chad's Dad

    Chad's Dad Junior Member

    Joined:
    Jun 22, 2010
    35
    10
    0
    Location:
    Austintown, OH
    Vehicle:
    2017 Prius
    Model:
    Three
    Did it again over the weekend when the temp was below zero. ECO made it stop doing it. Service is scheduled for this Saturday, will let you know what I find.