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Minor loss of power on small hills.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Austin Longenecker, May 3, 2020.

  1. Austin Longenecker

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    Howdy y'all, I've recently noticed a small power loss in my 2010 Prius. It's not noticable if you're not familiar with the vehicle, I can still get to highway speeds as fast as you would expect. But here's my problem: when going up slight hills, the vehicle seems to take more effort than necessary. For example, the display will show the energy all the way in the PWR range when it would normally be in the regular zone. Cruise control on a flat surface acts normal, but up a slight gradient, the engine must work significantly harder than it use to. You can also hear the engine working harder than it use to.

    128,000 miles
    Brand new 12V
    EGR system replaced last year
    Coolant level steady
    Minor oil consumption, but I keep on top of that.
    Battery charges and discharges normally.
    No check engine light.
    No warnings.

    My driving habits are averaging at 5mph above the speed limit. Here in Texas, we have 60 to 75 speed limits around my area. It's much more noticeable at high speeds. At 70 MPH, the gas must floor it to keep speed up a slight hill that would normally have a minor impact on gas consumption. MPG stays at 40-50 on a flat surface.

    Anyone have any idea?
     
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  2. tankyuong

    tankyuong Senior Member

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    Sounds normal
     
  3. Mendel Leisk

    Mendel Leisk Senior Member

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    Is it noticeably more effort than in past?
     
  4. Austin Longenecker

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    Correct. I've owned the vehicle for almost 3 years, it now takes noticeably more effort to travel the same hills than it use to. This began on a short road trip last week.
     
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  5. pjksr02

    pjksr02 Active Member

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    You didn't inadvertently flip from "Normal" to "Eco" mode, did you? I once did that, and it perplexed me for days. But that shouldn't change the engine sounds (effort).
     
  6. Austin Longenecker

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    Nope. I've checked that.
     
  7. bisco

    bisco cookie crumbler

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    did they do the whole egr circuit?

    get dr. prius and do a battery health check

    check the tires pressure

    clean the throttle body

    did you do the complete 120k service?
     
  8. Austin Longenecker

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    Honestly at this point, I have no idea. They told me they did the whole circuit, but those guys did so much damage to the EGR I had to have it replaced AGAIN under warranty at a different location. Tire pressures are normal. I have not done the 120K yet, but plan to once my local shop reopens to full service, which should be very soon.
     
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  9. Mendel Leisk

    Mendel Leisk Senior Member

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    I'm coming around to the only way to do EGR is DIY, or you just don't know. It's so poorly documented, Toyota's no help. Too: the intake manifold is part of the EGR circuit: EGR gas feeds into the intake via a pipe on the right side (standing at front of engine bay), runs down a gallery, and into capillaries (one per port). The capillaries in particular can clog up badly. If they're not cleared all the EGR cleaning is for naught.

    @ArmyChief has posted some pretty nasty pics (at 156K miles), in a pdf, first post here:

    Intake manifold EGR ports clogged - PICS | PriusChat
     
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  10. Austin Longenecker

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    Unfortunately I learned that the hard way.if only I had the tools and resources to DIY. As a college student I don't have my own place to store equipment or work on my vehicle.
     
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  11. ArmyChief

    ArmyChief Junior Member

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    Sounds like a fuel delivery issue (caused by skewed sensor(s) or fuel pump) or restricted exhaust.

    do you have a scan tool ?
     
  12. Austin Longenecker

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    I don't own one but have access to a cheap scan tool. I am unsure whether or not it is compatible with Dr. Prius.
     
  13. ArmyChief

    ArmyChief Junior Member

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    You won't need Dr. Prius. Regular Global scan tool will work for SOME diagnostics. You can monitor fuel trims at idle, 1500, 2500. Can also look at MAP (Manifold Absolute Pressure), BARO and determine engine vacuum.

    Can't guarantee anything (a good diagnostician should look at your vehicle with a OE-level scan tool). However, I can try to help if your interested in trying.
     
  14. Austin Longenecker

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    I appreciate the offer. I'm going to take my car in for the state inspection plus some regular maintenance and see of they can determine anything while they're at it.
     
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  15. Rebound

    Rebound Senior Member

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    That’s one reason why we have MeetUps
     
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