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2008 Prius weird whining noise

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Nomeo33, Jun 3, 2021.

  1. Nomeo33

    Nomeo33 New Member

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    2008 Prius
    Model:
    III
    I'm going to try and explain this all to the best of my abilities so bear with me. Last week while on the highway I was going 75 on cruise control when I felt the car jolt a little and started running rough. I was near my exit so I kept going. When coming to a stop and accelerating the engine/ front of the car had a real bad shudder. I ended up making it home and not driving it for a few days. Then I drove it to work just fine. Once I was off I go to drive off and the engine wouldn't start. Battery was moving the car but engine wouldn't kick on too charge it or drive the car. Eventually I kept going in circles (because I didn't want the hv battery to die like it was about too) and the engine soon engaged. Keep in mind the battery was charged enough before It came to that, so it wasn't because the battery was low voltage. When the engine started though there was a clunk and then a whining noise. This whining noise has continued now for a week. So far I've just changed the spark plugs, and ever since I did I haven't gotten any of the shudder like I experienced before I changed them. The spark plugs had a bit of oil on them but also fuel. They smelled really strongly of fuel, which may suggest a fuel injector is stuck open. Only one spark plug was dry and that was the 3rd. I've also went ahead and changed my pcv valve because it needed done. The thing is though, the car never through a code. I've unplugged the car from the battery to reset the ecu's and even still I can't get the car to throw a code. The whining noise seems to happen at lower speeds, up to 35 mph, and only does it when the engine is on. Not when it's in electric only. I've also put my car in neutral and let it coast and the noise isn't apparent then either. Which makes me think it has to be something with the engine. From what I've read it seems like it's either the fuel injectors, coil packs, or the rare transaxle issue. The injectors and coil packs should throw a code though and they haven't. The transaxle issue is said not to throw a code until it is fully dead. My engine seems to be running rougher, I'm getting lower fuel mileage, and it has a harder time at higher speeds. Does anyone know what this could be? Any help would be greatly appreciated. This Prius has over 300,000 miles ( I've had to change the combination meter) and I'm hoping to get more out of it. The noise also seems to be affected by acceleration.
    I will post a video as soon as I found out how.
    Also I forgot to mention, I've had a leak from my transaxle for a while now. I've changed the fluid after this all happened so I could check the color out and see if there were metal shavings. The fluid smelled burnt and their were a expected amount of shavings on the magnet, I wouldn't say it was a large quantity.
     
  2. Nomeo33

    Nomeo33 New Member

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  3. dolj

    dolj Senior Member

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  4. Nomeo33

    Nomeo33 New Member

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    Sorry about that I'm new here.
    I'm revving the engine to exaggerate the sound. It's the whining noise, I can take more video later if need be.
    Here is the link:
     
    #4 Nomeo33, Jun 4, 2021
    Last edited: Jun 4, 2021
  5. Krokettenslayer

    Krokettenslayer Junior Member

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    Have you checked the belt and the mechanical waterpump that is driven by it?
     
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  6. ChapmanF

    ChapmanF Senior Member

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    What did you change between the early revving (0:14 to 0:19 or so) without the noise, and the later revving with the noise?
     
  7. Krokettenslayer

    Krokettenslayer Junior Member

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    Looks like the car was at least put from P into D.
     
  8. Aaron Vitolins

    Aaron Vitolins Senior Member

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    It definitely sounds like bearings in the transaxle. Low or no fluid is really the only way to damage the planetary gear set (transaxle). Even small shavings is a very bad sign since there are no clutches like in a normal automatic, it’s okay to have some small shaving in a normal automatic since it’s from the clutch pads.

    Your Prius could still run for thousands of miles, but you have the reality of damaged bearings, and put up with the noise.
     
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  9. Nomeo33

    Nomeo33 New Member

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    I have not, what steps do I take to check these?
    New update though, the engine died yesterday while driving. I turned the car on and off and it started back up and drove me an hour home. I got error codes p3190 and p0a0f.
     
  10. Nomeo33

    Nomeo33 New Member

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    When I replaced the fluid it smelled burnt, it had been leaking for a while but is completely full now. Is there a way to check this? Should I be looking for shavings on the bolt magnet like I did?
     
  11. GrayRaceCat

    GrayRaceCat Junior Member

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    You mentioned you changed the PCV, good, next I would clean the Mass Airflow Sensor (MAF) check/replace the air filter, Clean the Throttle Body, clean or replace the spark plugs (depending on how many miles they have), reset all fault codes. While it is possible that your noise is the belt-driven water pump. (I have changed a few due to worn-out shaft bushings) It is more likely the sound you are hearing is the MG spinning up the ICE in an attempt to start it. I strongly believe the noise will be gone once the ICE is running properly. I've included a link to a video explaining the codes.
     
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  12. Nomeo33

    Nomeo33 New Member

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    2008 Prius
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    III
    Thank you, I'll try these options. I've already changed spark plugs, cleaned throttle body, and replaced the air filter. I'm down to cleaning the maf sensor and/or checking the coils. I appreciate the video and I'll keep you updated with any changes.