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Still Misfiring After Cleaning IM - Please read

Discussion in 'Gen 3 Prius Technical Discussion' started by dirt657, Dec 1, 2018.

  1. dirt657

    dirt657 Member

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    Hey there everyone, my name is Cole. I own a 2006 Prius as a daily driver and I do some fixing and selling over other Priuses on the side, usually with dead hybrid batteries. I recently took apart a prius that I am working on, a 2010, because of a 1 and 2 cylinder misfire, causing severe shaking, always at low speeds/rpm levels. When it misfires otherwise, it happens at low speeds or idle. As soon as the injectors start squirting more fuel into the engine, she clears up. Upon putting the car back together, the car definitely runs better more often, but when the misfiring occurs, it is just as bad as before I cleaned the IM. Let me tell you everything was FILTHY and has since been cleaned thoroughly with pipe cleaners as well as a bunch of carb cleaner.

    This is my misfire checklist thus far as well as what I have left to do.

    Spark plugs replaced 30k ago
    Ignition Coils replaced
    Injectors and seals replaced
    Injector seating holes cleaned
    Intake Manifold Cleaned (Tube diameterAbout the size of a BB before cleaning)
    EGR Pipe cleaned (Very clogged)

    Left to do (according to forums)
    Replace PCV valve
    Replace EGR Valve
    Clean throttle body (Didn't look dirty upon inspection)
    Replace Spark Plugs again? (They were replaced before I bought the car)

    I used this video below for reference. In the comment section, someone mentioned this: "glad you finally did this video but I think you missed an important part of the manifold that needs to be checked. inside each runner there is a small port on the bottom. when I removed mine to clean it, 3 of them were completely blocked up with carbon build up. it was actually causing a cylinder misfire. I used pipe cleaners to get all the way in there."

    - I then saw a few people mention that this fixed their issue as well. I thought I cleaned the intake properly, but apparently there are these little ports. Can anyone be more specific on these or maybe post a picture so I can see what he's talking about?



    If I'm forgetting anything, please let me know. It's getting closer to Christmas and I would love to sell this 2010. Would be a lot of presents. ;)
     
  2. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    Not all that visible, but near the bottom of the bigger hole is the 'slightly clogged' little port in question. Yours might look cleaner :cool:

    [​IMG]
     
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  3. Raytheeagle

    Raytheeagle Senior Member

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    Don’t forget to clean the egr cooler as part of the servicing otherwise you’ll miss a key component ;).

    Good luck and keep us posted (y).
     
  4. dirt657

    dirt657 Member

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    Thank you very much for the speedy response. So it's way deep in the port is what you are saying? I can't really see anything but i can assume its down there.
     
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  5. dirt657

    dirt657 Member

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    Thank you. I actually got a deal on the EGR valve and the cooler. I appreciate your reaching out in such good time. Thank you.
     
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  6. SFO

    SFO Senior Member

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    If possible, can you take a picture and post what you are seeing.
     
  7. dirt657

    dirt657 Member

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    Sure. I'll be doing it this week. It's been actually raining here for once, keeping me inside.
     
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  8. PriusCamper

    PriusCamper Senior Member

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    Seems you're heading in the right direction, but might be premature to do all this work without first confirming head gasket and valves are still functioning properly... If you've got a bent valve or blown gasket swapping the engine with lower mileage wrecked Prius might be a better fix in the long run.
     
  9. dirt657

    dirt657 Member

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    It leaks no oil or coolant, I don't think it's a head gasket, and the way it runs well most of the time makes me think that it isn't a bent valve.
     
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  10. dirt657

    dirt657 Member

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    Funny you mention this...on my way home today from a friend's house the 2010 had a temperature flashing light that came on. It went off after a minute. I'm currently waiting on the car to cool down to add some more coolant, but this is the first time it has happened since I cleaned all the stuff I wrote about above. I think (am seriously hoping) that the coolant has finally just recirculated since I didn't add any since I started it up again. I lost a bit of coolant while pulling everything off doing the intake. I've also heard that the a bad intake manifold gasket can also contribute to this. We'll see when I drive it tomorrow. As soon as my EGR assembly gets here I will replace it.

    Next question, is it really true that its easier to engine swap than it is change the gasket? I'm trying to save as much money on this repair as possible because I want to be able to flip it and make a clean 3 grand.
     
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    It is not necessary to remove any coolant lines when removing the intake manifold. If you unbolt and lift off the throttle body with coolant lines attached, they have plenty of slack, you can just shift the throttle body over to the inverter and tie it there, out of the way.
     
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  12. dirt657

    dirt657 Member

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    I was also changing the injectors whilst completing this job. Maybe I removed them by accident anyway. I was following a video and the guy removed the lines.
     
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  13. dirt657

    dirt657 Member

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    Just went out and filled the coolant tank to the brim. I'm pretty sure it's not a headgasket (I will compression test anyway to be sure before I clean everything I said I would) because I checked the oil and it was perfectly fine, and maybe 3/4 of a quart low which is where I saw it was last time. I also added oil. I remember one of the coolant lines didn't fit as snugly as the others. I'm gonna check that line in the morning and if its coming from there I know its that. I'm almost entirely positive it isn't the head gasket. Stay tuned....can always use the help.
     
  14. Mendel Leisk

    Mendel Leisk Senior Member

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    Yeah I think I know (and appreciate) that video, but yeah: no need to disconnect those. Right now you've got bigger fish to fry, but anyway, if-and-when:

    Somewhat similarly if you happen to be removing the EGR cooler:

    The video for that shows the coolant lines clamped before removal, and then when they're removed, about a quart of coolant drains out of the cooler, which is mostly higher than the clamped lines. In that instance, if you just drain a couple of quarts from the radiator before starting any coolant line removal (into a clean container), it drops the coolant level below the cooler, and when you disconnect lines there's no spill. There's at most a few tablespoons coolant at the lower back corner of the cooler: just lift the cooler off without tipping, then add that trapped coolant to your previous preemptive drain.

    When the EGR system is completely reassembled, pour the drained coolant back into the reservoir, and you haven't spilled a drop. The reservoir level will end up slightly high, and gets back to normal with a few days driving.
     
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  15. PriusCamper

    PriusCamper Senior Member

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    By 'easier' I meant more the cost, rather than the actual repair challenge. And the cost of the work depends on who is doing the work... And when it comes to long term costs, it has alot to do with how many miles you have on the engine. An engine with a 1/4 million miles is cheaper in the long run to swap out with a wrecked Prius engine. But if you're talking about only 100K on the engine, then the head gasket is the least expensive fix.

    At this point you've done so much work on the engine, you might as well play out the hand you've been dealt and hope for the best.
     
  16. Mendel Leisk

    Mendel Leisk Senior Member

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  17. dirt657

    dirt657 Member

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    I see what you mean. I drove it today and checked the coolant and it seems to be right where I left it, so I'm not too concerned about it.
     
  18. Raytheeagle

    Raytheeagle Senior Member

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    #18 Raytheeagle, Dec 6, 2018
    Last edited: Dec 7, 2018
  19. Mendel Leisk

    Mendel Leisk Senior Member

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    The link kits are full, for use with engine tear-down, head gasket, oil pan, coolant pumps I think.
     
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  20. jack black

    jack black Active Member

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    Healthy engines don't overheat for no reasons. This is a powerful clue. I see that you're in a denial about HG, but until you look inside the cylinders with a boroscope, you just don't know.