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Sneezy Prius

Discussion in 'Gen 3 Prius Technical Discussion' started by schmuber, Jan 31, 2019.

  1. schmuber

    schmuber Member

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    2010 Prius base, 225,000 miles odometer reading.

    When it's freezing, the car will stutter and shake violently at cold start, sometimes throwing P0303, occasionally P0301. Stutter continues for a minute or so, then it works normally. Lots of fog from tailpipe during the "stutter" phase. Oddly enough, if at first stutter I turn the car off and back on, it decreases the "shaky warmup" time significantly.

    When it's extremely cold, the engine shakes like an RUD event is imminent, then CEL comes on along with a P0300+P0301+P0303. Once warmed up, car operates normally… with a small caveat. Whatever causes that stutter, manages to freeze again in a few minutes (or sometimes even seconds), for example while waiting on a long traffic light or a railroad crossing. Tap the gas pedal and… Brrt pfft, shake your booty!

    The colder it gets, the worse are the symptoms. I feel like it could really RUD on me when the outside temperatures get below 10F, so any help is much appreciated.

    I'm completely puzzled by this. It seems that whatever is causing the problem has a minimal heat capacity and are not directly connected to the engine, hence it freezes back to its "troublemaker" state rather rapidly, even while the rest of the engine is hot.

    …A few more details.

    • I'm an Uber driver, so I drive a lot. About 200 miles a day on average.
    • When these symptoms first manifested in late December, I cleaned the throttle body, intake manifold and EGR pipe (and changed a PCV valve while at it). It's really hard to tell if it helped, since around the same time the cold spell went away and it was warm here (above 32F) up until recently.
    • While cleaning the intake manifold I had a chance to inspect the engine for any irregularities. Nothing seemed to be out of the ordinary, no gunked up injectors or unusual deposits.
    • Spark plugs are good to go for at least 30K more.
    • I haven't cleaned the EGR cooler yet (royal pain, but it's on my todo list).
    • Haven't checked injectors for resistance either.
    Any ideas?
     
  2. ericbecky

    ericbecky Hybrid Battery Hero

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    May as well check cylinder compression as well.
     
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  3. sam spade 2

    sam spade 2 Senior Member

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    Before going to all of that trouble, I would put a healthy does of Techron in a couple of tankfuls of gas.

    Actually, I would start out with Berrymans B12 Chemtool in a couple of tanks because it is a better heavy duty cleaner, the followed by Techron which also has some injector lubricating properties.

    Another thought is a failed coolant temp sensor......so that the engine never "knows" that it is cold to enrich the mixture a little bit.
     
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  4. bisco

    bisco cookie crumbler

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    have you cleaned the egr circuit?
     
  5. ericbecky

    ericbecky Hybrid Battery Hero

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    Said he has not done egr, but is on his list.
     
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  6. Raytheeagle

    Raytheeagle Senior Member

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    How’s the coolant level?
     
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  7. schmuber

    schmuber Member

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    Plastic bottle or a metal can? There are quite a few vastly different products under the same name.
     
  8. FnRedPrius

    FnRedPrius Active Member

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    Although being a relative Prius newby and based on my current experiences and massive research, MHO is that the EGR has led to a head gasket failure. When at idle or sometimes at a "float" throttle position, the antifreeze will foul the plug and depending on how much may be aspirated in the "Atkinson Cycle" and introduced the other cylinders. I have taught SWMBO to stomp the accelerator when she feels the shudder, even if only for 2 seconds. We are losing antifreeze and that is the only place it can be going. New plugs will help a bit, but when you pull them you will see which cylinder(s) have the leak. We have had (as many others) the exact same symptoms and codes for misfires in each cylinder along with random misfire codes. It actually behaved all week until this evening.
    I am going after a donor engine for ours in the morning. I don't have the time to pull an engine, tear it down, mic everything, then do the machine work, reassemble and install. I gotta work for speed this trip..
     
    #8 FnRedPrius, Feb 7, 2019
    Last edited: Feb 7, 2019
  9. Grit

    Grit Senior Member

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    A great post that bill norton will not read.
     
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  10. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah get on that. Watch @NutzAboutBolts videos if you haven't already, pinned in 3rd gen maintenance forum.

    I'd also consider an Oil Catch Can install.

    Still, with the symptoms, and the miles, this may be rearranging deck chairs on the Titanic: might be head gasket already on the way out, or who knows.
     
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  11. FnRedPrius

    FnRedPrius Active Member

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    OP, As I am living through this as of about a month ago (or a little more), the very subtle symptoms of the EGR clogging leading to the head gasket failure may not become appreciable ( I love that word) until you get the P0300 thru P0304 codes handed to you out of the blue. A head gasket has either failed or not, similar to pregnancy. Ours has over 240K and the EGR wasn't even a thought, even though I (at least thought I was) am about anal about PM. SWMBO drives the daily, and I may drive it 2 or 3 times a week. Out first symptom was the serious shudder and multiple codes as she was traveling down I-95 at 65 MPH in very heavy traffic. Naturally she was over 100 miles from home.

    I went this morning 130 miles (one way) to pick up a 2016 engine to correct my failure to properly maintain her car beyond the 5K oil changes and the wear and tear items. The bright side is that I will have another engine that should go over another 240K plus IF I stay active enough to keep up the the next generation of new Prius challenges.
     
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  12. sam spade 2

    sam spade 2 Senior Member

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    Can.
    Looks similar to the SeaFoam can but the product inside works a LOT better......and for about 1/3 the price.
     
  13. sam spade 2

    sam spade 2 Senior Member

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    Just because those two things happened in sequence, does NOT necessarily mean that there is a cause and effect relationship.

    In fact, there is little to no "connection" between what happens in the crankcase and what happens to the head gasket.