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Engine Rattle with Load

Discussion in 'Gen 2 Prius Main Forum' started by prius_power, Oct 11, 2020.

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  1. prius_power

    prius_power Junior Member

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    Good day all,
    I've had my Prius for almost 5 years now. It's a 2008 with just shy of 200k miles on it. It's always had a rattle when there's been a low RPM load on the engine, but a friend confirmed that it's coming from the engine itself.
    Also worth noting that this doesn't happen at idle or when revving in park, only when there is a load on the engine.
    (He used a stethoscope to listen) Has anyone had a similar sound from their Prius and if so, what was the fix?

    Thanks!
     
  2. oldtechaa

    oldtechaa Active Member

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    If it doesn't happen at idle, why does it seem like you're not moving in the video? It might be helpful to hear it at different speeds under different loads, but my first guess is the water pump. It doesn't sound like it's inside the engine, like rod knock or pre-ignition or valve rattle, it sounds more like a bad pulley/bearing on the water pump. More experienced people can probably help you out more though.
     
  3. edthefox5

    edthefox5 Senior Member

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    Your stethoscope friend where is the noise coming from on the engine?

    If its not throwing a missfire code its probably external. Take the belt off and see how loose the water pump pulley is. With the belt off turn the car on and listen see if its gone. If still there its internal.

    How many times has the car thrown a check engine light because it ran low on oil and now how much oil does it eat?

    Most common issue the piston rod bearing fails and if continued driving it likes to make a hasty exit out the side of the block. Seen many of those on those on this site.
     
  4. prius_power

    prius_power Junior Member

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    Never threw a misfire code, and never threw a check engine light or any warning light for low oil. Also oil level is normal/full.
    I'll give it a shot with the belt off to see if it goes away. I'm hoping it's external though.