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2007 Engine sounding louder

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Roosterleft, Jul 9, 2016.

  1. Roosterleft

    Roosterleft Junior Member

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    I wish I knew how to describe it better - perhaps some of you can help me diagnose it better.

    The engine is sounding louder. I noticed it slightly, and thought it was because I have been blasting the AC in a heatwave we're having. Then, on a cloudy 60-degree morning, a friend commented that it was louder. This friend is one who is continually surprised by how quiet my car is, so that was surprising.

    It generally sounds like the engine is working harder. Slight vibration when accelerating, but I'm unsure if this is new. I have to turn off the AC and radio to be sure I'm hearing it (because of the noise of the AC, it still happens with it on). It's almost like a large baseball card is hitting the spokes of a tire. The noise doesn't happen when the car is braking or stopped.

    It seems minor and phantom-like to bring it in.

    85,000, no problems or work needed so far. Home is New England climate.
     
    #1 Roosterleft, Jul 9, 2016
    Last edited: Jul 9, 2016
  2. bisco

    bisco cookie crumbler

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    how many miles on her? could be a leak in the exhaust, or working harder to recharge a weak hybrid battery. or even the 12 volt.
     
  3. Roosterleft

    Roosterleft Junior Member

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    85,000, no problems or work needed so far. Home is New England climate.
     
  4. JessO

    JessO Junior Member

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    My wife's '05 Camry got louder over time, the exhaust pipe in front of the catalytic converter had rusted enough to have a little hole. I had it patched at a garage by a welder for ... $70 ish. It failed later on, but I'd learned about parts shopping and doing that work myself.

    However, I was in the Army at the time and had a safe DIY garage to get a lift, and expert advice for getting this part off, and the new part on.

    Can you see the underside of you car, and look at the exhaust? That's my guess, emphasis on guess.

    Good luck.
     
  5. edthefox5

    edthefox5 Senior Member

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    Mine started doing this too. It may be becasue the Hybrid battery is getting old...not holding a charge very well and the engine has to work 100% harder when there's not a nicely charged battery to participate. You can confirm this by watching the battery volume on the mfd and see how many times it goes into purple bars and how fast or how long it takes to put some blue bars back in the tank or if the noise coincides with low battery charge.

    And since you live in new England you may have substantial rust under there too. get a flashlight and look.

    If your not throwing any codes you should get a Hybrid Battery charger and see if you can charge and balance the pack. May extend the life of your battery for quite a while. I'm in the process of charging my battery today.

    9 years is a long time for a battery.
     
  6. 69shovlhed

    69shovlhed Surly tree hugger

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    you need to determine if the noise is coming from the engine itself, or from the exhaust system. hopefully, its the exhaust. I assume you did check to make sure your oil is full and clean?
     
  7. Roosterleft

    Roosterleft Junior Member

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    @edthefox5 It's interesting you say that about the purple bars. Unrelated to the noise, I've been checking the battery bars every once in a while in hopes of any signs the battery might be going (would want to sell before the 10yr warranty is up if so). I have noticed the bars going down to purple more often, but again assumed it was because I've been using the AC every time I'm in the car now. Would that be normal for the summer?

    As for oil, had an oil change within the last month. Won't be able to check for rust or the exhaust system myself unfortunately.
     
  8. edthefox5

    edthefox5 Senior Member

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    Check your battery bars more often. I can almost guarantee your battery is heading south. To what degree I'm not sure but my car started making a very loud noise upon acceleration. Like its was missing the air cleaner or the car had a cold air intake.

    The Prius is designed to have a major participation in power from the battery. Its a very anemic little car when the battery goes soft and that tiny little motor does its best to satisfy the pedal demand. In order to do that its got to work really hard.

    The battery going has a few definitive symptoms. One is the mileage tanks. The other is its spends alot of time in purple. Goes to purple pretty easily like just sitting in a drive through.
     
    Merkey likes this.
  9. Kevin_Denver

    Kevin_Denver Active Member

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    I would watch your battery charge. When you have 3 or less bars, it's normal for the engine to work much harder to drive the car, and the additional noise is just the engine revving to a higher rpm. This can happen more when using AC, as when the AC is on, it draws significant power from the hybrid battery. If this same noise is occurring at a high state of charge and was not previously or if the character of the noise has significantly changed, then I agree with what others have said - it's likely an exhaust leak. Also keep in mind the sound of the engine changes after the first minute of use; the Prius runs the engine rich with a different timing for the first minute to warm the catalytic converter. If you listen closely, the sound of the engine changes after this warm-up cycle is complete.
     
    JessO likes this.
  10. Roosterleft

    Roosterleft Junior Member

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    I'm back a few months later with a "no update" update. I was due for an oil change this week and decided to bring it to the dealer so I could also ask about the sound. From a brief look the exhaust system looked fine and there doesn't appear to be rust. There's been no change in the noise or in how the car is driving for the 6 months since I first noticed it, so they suggested I keep an ear on it and bring it in if there are any changes.

    From all of your suggestions, I will pay more attention to the battery level and if there's any correlation there. With the hybrid battery warranty up before the end of next year, I may be looking for a new car soon!
     
    bisco likes this.
  11. Priusyipee

    Priusyipee Active Member

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    You would be surprised... The muffler can and does rust rust from the top where you would not see the damage. Been through 2 mufflers since my '05 was new and both failed from the top (underneath the heat shield). Car currently has over 283,000. Don't give up just yet.
     
  12. Roosterleft

    Roosterleft Junior Member

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    I'm back again -- a couple weeks after the quick lookover by the dealer, I got a flat tire. It was time for all new tires anyway, and that solved part of the sound. Didn't even cross my mind that if it sounded like something in the tires, it was probably the tires! Who would've thought. ;)

    The engine is still louder than it used to be, most notably when the battery is at either end of its charge (low or full), and when kicking on or off.

    I'm thinking of bringing it in for a general tune up -- what should I ask them to look for? In addition to this, there is a noise that happens when the brakes are depressed fully, almost like a belt skipping once or twice.
     
  13. Priusyipee

    Priusyipee Active Member

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    Now that you mention it, I did have a set of tires at one time that sounded like the wheel bearings were shot...The tires were LOUD!!! As soon as they were replaced, the roaring noises disappeared and my ride became more enjoyable!
     
  14. mapperky

    mapperky New Member

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    What tires are you using? I feel like my prius has always been loud, and awhile ago had wheel bearings replaced and it quieted it down signifigantly. But whenever ive had someone else drive my car they always comment that it shouldnt be this loud. Im using new Michelin Defenders i got earlier this year, and i dont know but maybe its those that keep it consistently loud at higher speeds. Ill also mention that, that the car is louder the faster im moving. Any insight? You using the same tires?

    SM-J727VPP ?
     
  15. edthefox5

    edthefox5 Senior Member

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    Yes its always been loud. Its a loud little car compared to a bigger sedan. Its all tire so if your running LRR tires and hyper inflating its going to be really loud.
    My wife loves the car but to me its a very loud & uncomfortable world class engineered little car. Its her car.