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60 mph power surging

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Fartsalot, Oct 18, 2018.

  1. Fartsalot

    Fartsalot Junior Member

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    2008 Prius
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    Base
    Hey guys,,, Here is my issue with my first Prius 08 91K on the clock.

    When Im on the road around 60 mph, a little less or more, I feel a small surge of power and then a small loss of power. I can feel it physically and I can hear a slight difference in the soft engine noise under the hood.

    It does this when Im just keeping my speed at the same level,,,this is annoying the heck out of me while I drive. Strangely when I activate the cruze control the problem goes away immediately and returns the moment I disengage the cruse. The drop in engine speed feels to be maybe 300 rpms or so,,,just enuf that I can feel the constant on and off power. There are no codes showing on the dash BTW and I made sure my foot on the pedal is steady and not causing the issue.

    Any ideas? I also have no history of the maintenance of the vehicle. Other wize it runs fine,,,the MPG on the screen indicated 40 to 42 mpgs avg. I guess the numbers are correct (roll eyes)

    Thanks
     
    #1 Fartsalot, Oct 18, 2018
  2. exstudent

    exstudent Senior Member

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    As you drive, look at the center display screen: Energy Monitor.
    "Surge" in power will correspond to exactly when the Hybrid battery provides energy for the electric motor to help propel the car.
    "Loss" in power will correspond to when the electric motor disengages, so the Hybrid battery can charge.​

    Remember, the computer will be doing this automatically, possibly many times a minute, to maintain HV battery charge, and optimal MPG.

    This alternation will occur even with the Cruise Control on.
     
    #2 exstudent, Oct 18, 2018
    Last edited: Oct 18, 2018
  3. Fartsalot

    Fartsalot Junior Member

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    2008 Prius
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    Base
    exstudent,,

    What you are saying is normal for me to feel this variation in the engine? I find this very annoying as I drive,, something like a little constant rattle in the dash that can not be located LOL. I have looked around on our forum and I found nothing mentioned by anyone. I'm surprised no one has mentioned it at some point.

    Thanks for your reply
     
    #3 Fartsalot, Oct 18, 2018
  4. exstudent

    exstudent Senior Member

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    Normal, yes. I guess everyone else just accepted it, as this is what it is like driving a Hybrid. You will get used to it in time, and won't even notice it anymore. On the upside, you will like the MPGs; small trade off.

    For lack of a better description, the Gen2 has a "hard" coupling/uncoupling of the electric motor, so to say. The Gen3 and Gen4 cars I have ridden in, I can't feel it, but I can see it on the Energy Monitor.

    Check your motor mounts as a precaution. Maybe yours are bad, which could make the coupling/uncoupling, harder, thus being felt more?
     
    #4 exstudent, Oct 19, 2018
  5. edthefox5

    edthefox5 Senior Member

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    It’s a somewhat heavy little car that is underpowered and needs constant input.

    What helps is to inflate the tires a little. Higher inflation also helps the road dithering which drives me crazy the constant steering input needed as the car follows every little rut in the road. You can’t just relax and let the car go straight. The horrible side effect of higher inflation is the car then rides like a stagecoach and hits every little bump very hard. Many people don’t notice this too much though but I sure do.

    Try 40 lb pressure all around most long time posters run there tires like that you get much better mileage
    And it really helps the road tracking issue. But hits real hard on poor streets.
     
    #5 edthefox5, Oct 19, 2018
  6. M in KC

    M in KC Active Member

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    And if you think 40lb is harsh try 44/42 front to rear bias. I've found this to be a good setup with good LRR tires for maximizing mileage and suppressing the sensations edthefox5 describes but you do pay the lumber-wagon, ride quality penalty.
     
    #6 M in KC, Oct 19, 2018
    edthefox5 likes this.
  7. edthefox5

    edthefox5 Senior Member

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    Yes sir I tried the 42 all around with the god awful integritues back in the day. Man does it hit potholes hard.
    But mileage was awesome and the road tracking 100 percent improved.

    Lots of trade offs on this little car. My wife loves the car and won’t let it go though. She doesn’t mind the suspension at all but the seats really suck on long ride. After L5 back surgery I cannot tolerate the seats
    On a long drive.
     
    #7 edthefox5, Oct 19, 2018
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