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Excessive Road Noise

Discussion in 'Gen 2 Prius Main Forum' started by Joe1987, Dec 9, 2018.

  1. Joe1987

    Joe1987 Cheyenne Joe

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    Vehicle:
    2006 Prius
    Model:
    Four
    We have two Priuses, a 2006 and a 2013. We are very pleased with the Priuses except for one annoying problem. When we approach 50 mpg or faster in either car, there is excessive road noise in the passenger cabin. Most of the noise appears to emanate from the rear of the car. When I've had an occasion to be a passenger in the back, I couldn't hear the conversation being held in the front.

    I'd like to know if anyone else notices this problem and if so what, if anything, did they do to resolve the excessive noise (please don't tell me to turn up the volume on the radio!). I am thinking of possibly having the cars undercoated.

    One other question. Does anyone know what the latest disc version is for a 2006 GPS Navigation system?

    Thanks for your help.
     
  2. SFO

    SFO Senior Member

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    Search in these forum for possible "excessive road noise" workarounds :
    Gen 2 Prius Audio and Electronics | PriusChat
    Gen 2 Prius Accessories & Modifications | PriusChat

    Here are some example results for the term "deadening" from the above audio and electronics sub-forum :

    https://priuschat.com/search/101801317/?q=deadening&o=relevance&c[node]=13

    There are many material options you can choose from, be they expensive, spray on, or even duct insulation.

    A simple search pulled up this thread regarding your request for the "latest dics version" for a gen2 :

    What is the current (or last) NAV DVD for gen 2 prius? | PriusChat
     
    Raytheeagle likes this.
  3. frodoz737

    frodoz737 Top Wrench

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    Have had a 2010 and now a 2015 and never had the issues you describe. So...based on that alone...I would check your rear wheel bearings, alignment, wheel balance and tire wear patterns if you are not religious about rotating. The only other obvious guess would be you've been driving in "quiet" Prii so long that your sensitivity to noise has increased. If that's the case, the whole rear hatch area is very easy to "sound proof".
     
    #4 frodoz737, Dec 9, 2018
    Last edited: Dec 9, 2018
  4. PriusCamper

    PriusCamper Senior Member

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    Vehicle:
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    This problem is 80% tires 20% vehicle insulation... You can buy tires with the lowest noise rating...

    Highest mpg (low rolling resistance) tires are reasonably close to the quietiest, so you don't have to lose high MPG if you don't want to.

    Once you have the right tires keep adding 1 or 2 psi in all the tires and drive on the same stretch of the noisest freeway each time and use a sound decibel measuring app on your phone. Eventually you'll figure the right tires pressure for the quietest ride.

    Once you're done with optimizing tires, spend a few hundred dollars or less on each car to get it detailed and painted with an additional layer of undercoat. After that pull out the front seats, pull up the carpet and add a second layer on insulation. Then buy some really heavy duty floor mats... Beyond that you can do sound deadening in the door panels. and roof, but probably not worth the cost.

    But in general, they're a 12 year old car and a five year old car and are designed for high MPG, not quiet luxury.... Expecting them to be a quiet ride at freeway speed is expecting too much.
     
  5. bisco

    bisco cookie crumbler

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    michelin energy save a/s made a huge difference in my 2012, not sure if they are available in the gen2 size
     
  6. Usle

    Usle Active Member

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    My 06 and my 11 both needed front wheel bearings at 40,000, a loud noise starting below 40, and progressing in db with mph, new bearings made each silent.

    A tinny round cabin makes sounds confusing.

    Gen2 tires were undersized, gen 3&4 are the correct size.
    The speedometer is incorrect in gen2 prii, th speedometer is correct in gen 3&4 prii.

    Gen2 tires 185/65-15
    Gen 3&4 tires 195/65-15
     
  7. MilkyWay

    MilkyWay Active Member

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    How excessive? Is it a loud humming that is kinda faint in the background but there lurking around just will not go away? Even if you have the radio on there is a constant hum? If so that is at least 1 bad wheel bearing, possibly more. You can feel it in the wheel if you cut hard to the right or left...the pitch will slightly change.

    You can take it to a mom/pop tire shop and ask them to drive it to see if it is tires. The ones by me do it for no charge....Or an auto repair shop.

    This is the noise I had from bad wheel bearings...Sometimes can be more subtle: