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2012 Prius II rattle when engine turns off at idle.

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by hilawfresh, Oct 4, 2022.

  1. hilawfresh

    hilawfresh New Member

    Joined:
    Oct 4, 2022
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    Location:
    Antioch CA
    Vehicle:
    2012 Prius
    Model:
    Two
    Greetings all,

    I hope someone can help me with my issue because I'm at a loss.

    I am currently experiencing the death rattle around the intake manifold. Most of the time, engine rattles at high RPMs then remains rattling on idle. On cold startup, there is no rattle, not until I press the gas. Pulled code and got P2119.

    Did my own troubleshooting and replaced PCV valve, cleaned intake manifold, EGR valve, cooler, and pipe. EGR cooler still have gunk but cleaned as much as I could.

    After troubleshooting, I did a cold startup and right away there is a rattle from same location. After a few seconds at idle, the rattle goes away. Then I pressed the gas pedal to achieve high RPM, rattle goes back and rattle stays at idle. But this time, rattle stays after engine is off after warmup. Sometimes there is no rattle in between low RPM and high RPM. Left the car on idle for about a minute and suddenly the RPM goes up as if the gas pedal is pressed then goes idle. The car did this for about 5-6 times before I decided to shutoff completely. CEL came out and had P2102 and P2119 code.

    I just bought a used throttle body from eBay hoping this can solve the issue. I'm looking to eliminate possible culprits and started on replacing the throttle body.

    I am at loss here and I hope someone can help if they had the same experience.

    Here are the link for the videos:
    Rattle when engine is on


    Rattle when engine is off


    Thanks in advance.
     
  2. Mendel Leisk

    Mendel Leisk EGR Fanatic

    Joined:
    Oct 17, 2010
    56,674
    39,222
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Codes are pointing to throttle body. Still, how many miles? Is engine coolant level stable? The EGR cleaning was recent, after knocking started?

    For the cooler, soaks with Oxi-Clean Versatile Cleaner will help.
     
    #2 Mendel Leisk, Oct 4, 2022
    Last edited: Oct 4, 2022
  3. hilawfresh

    hilawfresh New Member

    Joined:
    Oct 4, 2022
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    Location:
    Antioch CA
    Vehicle:
    2012 Prius
    Model:
    Two
    Hi! thank you for responding.

    Currently it has 190k miles.

    My coolant level is stable. Never seen the reservoir go empty.

    I just cleaned the EGR after I heard the knocking.I will buy the oxiclean and redo the EGR cooler cleaning.

    It was very strange when I heard the rattle/knocking after the engine turned off after warm up. I'm assuming EGR circuit can be eliminated in the problem since there is no circulation of air if engine is off. Could it be possible that the coolant going through the throttle body causes the rattle/knock?

    Thanks.
     
  4. Tombukt2

    Tombukt2 Senior Member

    Joined:
    Nov 29, 2020
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    Location:
    Durham NC
    Vehicle:
    2009 Prius
    Model:
    Base
    Engine sounds terrible. Holey moley. Funny thing mine sounded just like that before the Piston skirt and the piston rolled over and broke the rod almost exactly I don't know about when the engine was running and when it wasn't because at that time I was just driving the car going down a road where the engine would definitely be on
     
  5. elleonleo

    elleonleo Junior Member

    Joined:
    Aug 12, 2016
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    Location:
    bay area
    Vehicle:
    2010 Prius
    Model:
    II
    Any luck with this? I seem to have the same problem though I have not yet done any of the cleaning.
    -->
     
  6. klzeturbo

    klzeturbo New Member

    Joined:
    Mar 3, 2023
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    Location:
    montreal
    Vehicle:
    2010 Prius
    Model:
    ----Canada----
    Did you figured what was the problem?
    I think I have the same issue
     
  7. rrg1234

    rrg1234 Junior Member

    Joined:
    Jun 11, 2022
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    Location:
    New Jersey
    Vehicle:
    2011 Prius
    Model:
    Two
    220k, only cleaned the egr metal tube. Never been to dealer for any TSBs.
    Use mid grade fuel only since 110k.
    Death rattle pops up when very cold below 30deg and feeling damp outside, this week here.

    I keep it away every time with this trick since 110k.
    I was going to take it in but the dealer back then wanted to see it happen on demand, so I never went.

    My Trick/Solution every time for me.

    I add Lucas fuel treatment or the Marvel Mystery fuel treatment in the winter, not every tank. Just when I sense a little extra tiny vibration.
    Starts like butter after it mixes in, after my second start of the car to go somewhere.

    I also use higher octane when the weather is super cold.

    Last year it rattled in the summer 1 time. Thought my head gasket was it with 210k on it. I did my trick and no rattle till last week.

    Going to clean the egr system this year but I say that every year. This might be the one.lol
    My2cents.
     
    #7 rrg1234, Mar 5, 2023
    Last edited: Mar 5, 2023
  8. Seymour1

    Seymour1 Junior Member

    Joined:
    Feb 8, 2024
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    Location:
    22967
    Vehicle:
    2010 Prius
    Model:
    Three
    Rattle when turning off engine
    I have a P0401 code. No tags on car-unable to drive. I cleaned the IM, EGR valve, pipes and cooler. I also reconditioned the traction battery. After that, I still got the P0401 but no rattle. For no reason, now, I get a rattle when turning off the engine and an infrequent mild rattle while idling. It also idles up and down slightly, similiar to a lean-running lawn mower. I get the yellow triangle, check engine, and check hybrid system. My OBD2 reads P0401, P3190, P0A93 and P0C73 (I have ordered a new inverter water pump) I have also bid on ebay for an EGR valve (used, not cleaned) I cannot see anything wrong with my EGR valve, but who knows? Any ideas? Note: When cleaning the IM, I used brake cleaner and carb cleaner with MAP sensor in place. (Damaged MAP sensor?)
    I am also trying to set up and learn Techstream. Maybe it will help after I can use it.