Third Gen Surging on city streets in cold weather

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by HprDad, Jan 23, 2014.

  1. HprDad

    HprDad Junior Member

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    Similar to the issue posted here: ( Third Gen Prius Surging on Highway in Cold Weather | PriusChat ), my Gen III has twice now had episodes of surging, in the city, in the past couple weeks. Thought I'd post a separate thread, since the conditions were significantly different, other than the cold. Temp was about 5 degrees F, speed about 30 MPH, HSI just below halfway, go pedal held constant. While speed was roughly constant, the iMPG readout was bouncing between extremes, from 100MPG to perhaps 20MPG, at a rate of about once per second, and the surge was easily heard & felt. It felt as though the ICE was going on & off, though I didn't have the energy screen on. It seems just like a classic under-damped control system problem. This condition persisted for probably 30 seconds, until the next stop light. Drivers seat heat was *on*, HVAC temp set to 68. The car had been sitting for perhaps an hour after last driven, and been running for <10 minutes when this occurred; The ICE was warmed up enough so that at the next stop, it shut off, though it was cold enough outside that it didn't stop at every red light. Increasing pedal pressure to put HSI above halfway, the surge stoppped; Decreasing pedal pressure to put HSI back below halfway, the surge would start again.

    Honestly, it reminded me of an old briggs & stratton air-cooled lawn mower engine, with a sticky fan driven governor. A bit quieter, though. ;) I don't plan to take it in, since it rarely occurs, and seems more like a design issue than a specific problem to be fixed. So, I guess I'm just looking for some discussion.
     
    #1 HprDad, Jan 23, 2014
  2. GrumpyCabbie

    GrumpyCabbie Senior Member

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    What mileage are you at?

    I experienced similar with my car last summer where it was surging and almost stalling, ran rough and mpg's went right down and the HV battery was cycling much more; probably trying to make up for the lack of engine power. But then it was ok for a few months and then did it again but much worse causing me to drop the car at the dealers..

    Cut a long story short, it turned out the EGR valve was blocked up and needed replacement. My mileage was about 79,000.
     
    #2 GrumpyCabbie, Jan 23, 2014
    telmo744 likes this.
  3. eric1234

    eric1234 Active Member

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    That's pretty much exactly what I experienced. The only difference was that mine occurred at highway speed (as described in the other post).

    I have noticed that mine occurs when very cold 5-7 Degrees F, and then the problem goes away when warmer, like 20 degrees F. (or, at least the last 2 days, it occured in morning on way in to work, with low temp, and not on ride home, with warmer temp)
     
    #3 eric1234, Jan 24, 2014
  4. eric1234

    eric1234 Active Member

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    I'm at about 82,000 miles.
     
    #4 eric1234, Jan 24, 2014
  5. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Mine happened both in traffic and on a flat 60 mph road cruising along. If I recall, it was cold at about 5c but not very cold. Towards the end it didn't matter if the car had just started up or had been running for a while, it just ran rough.
     
    #5 GrumpyCabbie, Jan 24, 2014
  6. eric1234

    eric1234 Active Member

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    Thanks... Maybe EGR replacement time is coming. Was it very expensive?
     
    #6 eric1234, Jan 24, 2014
  7. bestmapman

    bestmapman 04, 07 ,08, 09, 10, 16, 21 Prime

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    Just for reference I have not had that happen at all. I am at about 155,000 miles and 4.5 years. It doesn't surprise me though. Good to know about the EGR valve fix.
     
    #7 bestmapman, Jan 24, 2014
  8. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Our warranty is different here so yours may still be covered.

    It was £425 ($700) but we have 20% sales tax and our prices are more expensive generally. Some say you can clean the egr out, but I just needed the car on the road quickly. It's expensive as it is one whole unit on the right hand side of the engine area. I might be wrong but I'm sure someone said it's water cooled or something.

    It's not like the cheap plastic ones from 10 years ago :(
     
    #8 GrumpyCabbie, Jan 24, 2014
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