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Prius Gen 2 weird sound on low battery

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by priusowner297, Jul 17, 2020.

  1. priusowner297

    priusowner297 New Member

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    Hi I just bought a Prius Gen 2 a while ago. My first prius. It has around 125k km on the odometer. Now whenever the hybrid battery is low (purple region) and engine starts to charge it the car becomes extremely noisy and has some what of a rattle(see video attached). During this a slight vibration can also be felt inside the car. Secondly i also feel as if the car is slightly heavy when accelerating and rpms go quite high in my opinion. Could anyone give me some advice on this, if its normal and if not what should I do. As i am quite new to hybrid cars.
    Secondly could anyone advise me on how to clean the engine bay on a hybrid :p

    Video:
     
  2. SFO

    SFO Senior Member

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  3. priusowner297

    priusowner297 New Member

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    No i only own this one but it is a gen 2 and 2011(all the paperwork says so), I think they rolled out both gen 2 and 3 till 2011 in Japan( where my car is imported from).
    And nope no warning lights on.
     
  4. SFO

    SFO Senior Member

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    Though the mileage is low, inspect the spark plugs and check if the valve cover gasket is leaking into the plug wells.

    You might want to add some PEA into the gas, assuming you have added some bad fuel recently.

    Can you locate a toyota hybrid compatible OBD2 scanner, and see if there are any codes (DTCs) that can be retrieved.
     
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  5. TMR-JWAP

    TMR-JWAP Senior Member

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    That inverter definitely looks like a Gen 2. My experience is very similar to yours. For example, if I sit in the car with the AC on and the battery gets down to 2 bars, the car acts like a dog if I decide to drive away while at 2 bars. The car will start acting normally as the battery charges up. You can see this on techstream, as the battery discharge limits are adjusted by the ecu to limit max discharge rate when it's low like that. As the current discharge is limited, the engine rpm will be higher when trying to drive. Half the Gen 2s I've driven have been a bit noisy when the battery is at a low SOC. I don't think it's anything to worry about.

    Secondly could anyone advise me on how to clean the engine bay on a hybrid

    I use compressed air. I'm not a fan of spraying water into a Prius engine compartment. Too many places for it seep into and cause HV system isolation issues.
     
  6. edthefox5

    edthefox5 Senior Member

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    When your driving in purple bars the cars hybrid battery has nothing to contribute power wise which is a big problem as the bulk of the car's power and torque comes from a healthy hybrid battery. So you press harder and harder on the gas pedal demanding the engine to replace that lost battery power and the sad fact is it cant. Its simultaneously powering the car and charging the battery by spinning up an mg.
    So engine is screaming and you not going anywhere. All your doing is flogging the engine where what you should be doing is going easy on the gas and let that battery charge up.

    If its got the original hybrid battery your looking at the first stage of Hybrid battery death. That quick tanking to purple. The fact that the car has such low miles almost guarantee's that.

    You can mitigate the purple easily though for now. Just put the car in Drive step on the brake and press the gas pedal down enough to turn on the charge current arrow pointing to the battery in the energy monitor. Been dong that for years. Don't floor it just lightly increase the gas in power brake mode till you see that arrow come on. Been doing that at lights when it started the purple bar tanking. Its should go to one or 2 blue bars fairly fast like 2 minutes unless the battery is really tired. Eventually I went on to a Promlong charger system lots of us use and got a couple more years out of it.