1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Cold start rumble from engine or gearbox

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Jason in OZ, May 15, 2016.

  1. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    hello everyone.

    I'm in need of some advice.
    My 2006 G2 Prius has from the day I bought it (2.5 years ago) had a cold start rumble the comes from up front.
    It is getting worse.

    This morning it was particularly bad.
    It's not a misfire. That much I do know.
    It sounds like a really bad thrust bearing noise that might be from a manual gearbox.

    The thing is, it only happens at cold start.
    It goes away very quickly. If the car is in P or N the noise does not happen. (Engine running)
    If the car is in D, with the car not moving, the noise happens. (Engine running)
    As soon as the break is released, the noise goes away. (Engine running or not)
    Even if the car is moving at 1kmh, there is no rumbling bearing type noise.

    This noise is NOT present if the car is in EV mode.

    The above leads me (maybe erroneously) to thinking that the noise is in the gearbox.
    not the engine.

    I'm wondering if anyone here has had the same issue, and or knows what it is.
    I'm trying to get a handle on what it's likely to cost me to put right.

    I know that before too long I will need a replacement battery (HV)
    And now possibly major engine or trans work too.....

    Thanks in advance
    Jason.
     
    #1 Jason in OZ, May 15, 2016
    Last edited: May 15, 2016
  2. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    Sounds like the trans. Fluid may be very low. Have you ever checked the trans fluid? And has it ever been replaced?
    How many miles?
     
  3. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    Thanks for the reply.

    The car has 224k km on the clock

    I don't have a full history for the car.
    But the trans has not been serviced while I have owned it.

    Is there a seperate trans dipstick to check fluid levels ?

    Jason.
     
  4. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    no, just a plug. fill on a flat surface until fluid starts coming out. might be worth changing it, how many miles have you owned her?
     
  5. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    The car had 181k km when I purchased it.
    I have done 43k km in the time I have owned it. Around 2.5 years so far.

    I will have to look for that plug and the instructions for checking and changing fluids and filter.

    Jason.
     
  6. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    there's no filter, and there are threads here with pics. it's an easy job, but without a lift, the difficult part is getting the car level. be sure to use toyota tranny fluid.
     
  7. edthefox5

    edthefox5 Senior Member

    Joined:
    Jul 25, 2007
    10,096
    4,795
    0
    Location:
    Clearwater, Florida
    Vehicle:
    2007 Prius
    Model:
    Two
    224 k so thats 140,000 miles. Probably still has the original trans fluid. Go to lusciousgarage.com I think they discuss this noise issue.
    May be the chain in the trans ims.
    I would have the trans serviced asap and look for metal debris on the plug magnet end or pieces of metal in the fluid.
     
    bisco likes this.
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    Well - that is not very difficult. Raise up the front of the car with jack stands. When filling the ATF, raise up the rear of the car using a hydraulic floor jack at the center jacking point (the inverted tower that is pointing down.) Then you can easily get the car to be level.

    Use Toyota ATF WS fluid only.

    Regarding the startup noise reported by the OP, if that immediately goes away after you start moving, then I would say it can't be too bad. However it is a good idea to verify the condition of the transaxle ATF (and for that matter, all engine compartment fluids) when acquiring a used vehicle whose service history is unknown.

    OP says "...as soon as the break (brake) is released, the noise goes away." I assume he is referring to the parking brake. What happens if the parking brake is left released - does the noise still occur upon startup?
     
  9. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    By brake released, I mean the foot brake. As soon as the car starts moving, the noise vanishes.

    I should clarify. I'm not talking about the park brake or e brake as it's called in the USA. But the regular foot brake pedal.

    In P or N, there is no noise.

    Also, ambient temp plays a big part in the noise. Sunday morning when I went to work, it was around 9c and the noise was bad.

    Today it was around 22c when I started the car to go to work. The noise was there, but not as bad.

    I will try to get the fluid changed as soon as I can.

    I will report back of the noise goes away after.

    Jason.
     
    #9 Jason in OZ, May 16, 2016
    Last edited: May 16, 2016
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    18,198
    6,461
    0
    Location:
    Green Valley, AZ
    Vehicle:
    2015 Prius
    Model:
    Two
    I assume you are aware of the noise made by the brake actuator pump. You can force that pump to run by repeatedly pressing the brake pedal.

    The noise that you are concerned about is a different sound?
     
  11. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    Yeah. It's not the brake pump noise.
    It's definitely a bearing type rumble.

    I'll get the oil in the trans changed (probably overdue anyway)
    and see if that makes the noise go away or somewhat reduced.


    Seems odd to me that it's seems to be ambient temp related also.
    The colder outside it is when started, the louder the noise is.
    I've never heard it on a warm start either.

    Jason.
     
  12. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    engine mounts okay?
     
  13. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    As far as I know they are.
    There's no odd noises at any another time.

    I have had a thrust bearing fail in an old manual car I once owned.
    That's the kind of noise I hear at cold start.

    It's not a rhythmic kind of noise. Just a deep rumbling noise.


    Jason.
     
  14. bisco

    bisco cookie crumbler

    Joined:
    May 11, 2005
    107,571
    48,862
    0
    Location:
    boston
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    can you record and download it?
     
  15. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    I sure could try to capture it.

    It doesn't last very long though.
    By the time the engine is warm enough to shut off, the noise will be gone.

    I'll try to record it over the next few days and see what happens.

    Jason.
     
    bisco likes this.
  16. Jason in OZ

    Jason in OZ Active Member

    Joined:
    Dec 6, 2013
    271
    112
    0
    Location:
    Sydney, Australia
    Vehicle:
    2006 Prius
    Just updating this thread.
    The noise has only happened 1 time since the last post 2 weeks or more ago.
    What ever it is, it can't be anything that major.

    I will get the oil changed in the trans as soon as I can though.
    That just makes sense.

    I was not able to record the rumble when it did happen.

    I did try, but the cam didn't capture it.

    Jason.