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severe knocking noise, please help

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by pimpone60, Oct 15, 2008.

  1. pimpone60

    pimpone60 New Member

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    i just bought a 01 prius with 225,000 miles...the story is, they were driving down the interstate and it started this knocking noise...said the local toyota dealership said the gas engine is bad...i'm not sure it is...i start it and it starts good..then after a few seconds, all heck breaks loose...it starts this extremely loud knocking/rattling....seem to me that its coming from the trans area more than the engine area...the gas engine is shaking some like its got a miss and the scanner shows 2 cylinders misfiring..i'm almost sure its not the gas engine thats bad...whats weird is when your sitting in the car and its knocking like crazy, you take it out of park and the noise goes away..it takes reverse/drive fine and pulls in both of them...put it back up in park and the noise starts again...you can feel the knocking in the floor and the gear shifter...sort of a pulsating in the shifter....info center says everything is charging and working...if i had a way to rev the gas engine in neutral it might rule out the gas engine being bad....i'm new to the prius but i have been around cars my whole life...it almost sounds like the "clutch" between the engine/trans has come apart..or some gears stripped in the trans...call me if you want 870-476-0115
     
    #1 pimpone60, Oct 15, 2008
  2. Flying White Dutchman

    Flying White Dutchman Senior Member

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    the scanner shows 2 cylinders misfiring
    and you think its nog the engine
     
    #2 Flying White Dutchman, Oct 15, 2008
  3. pimpone60

    pimpone60 New Member

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    just because it shows a misfire does not mean the cylinder is dead...could just be a coil...still doesn't explain why it stops the noise when i take it out of park
     
    #3 pimpone60, Oct 15, 2008
  4. Flying White Dutchman

    Flying White Dutchman Senior Member

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    start adressing the misfire and see what happens
     
    #4 Flying White Dutchman, Oct 16, 2008
  5. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Since you've retrieved DTC that shows two cylinders are misfiring, it would seem reasonable to inspect the spark plugs, igniters, and fuel injectors for those two cylinders (cyl 1 is on the RH or passenger-side of the car) and see if you find any discrepancies.

    When the car is in Park, you can rev up the engine.

    You can also put the car in "inspection mode" to force the gasoline engine to run at all times. When the car is IG-ON (not READY) and the gearshift is in P, fully depress the accelerator pedal two times. Then shift to N and fully depress the accelerator pedal 2x. Then shift to P and fully depress the accelerator pedal 2x.

    Then press on the brake pedal and make the Prius READY. You will see the hybrid vehicle icon appear on the MFD and the gasoline engine will run continuously. Do not drive the car in this condition as the traction control is disengaged.

    Also note that at low forward speeds when you are in D, and at any speed when in R, MG2 is providing power to move the car (and the gasoline engine is not on).

    For your sake I hope that the engine is bad and the transaxle is good, because it will cost much more to replace the transaxle than to replace the engine.
     
    #5 Patrick Wong, Oct 16, 2008
  6. pimpone60

    pimpone60 New Member

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    which cylinders are 1 and 3? its almost the same cost on car-part.com for the engine or the trans/electric motor...this is the weirdest thing i have ever seen...when you start it cold, in park, it starts fine and runs quiet for alittle while...then its like you flip a switch and starts knocking...when you put it in rev,neutral,or drive, it stops the noise....shift it back into park and it starts it again...i'm almost positive(if thats worth anything) that the gas engine is good...i just don't want to buy a junkyard trans and it need the electric motor instead....another thing....i've been told not to let my mechanic change the motor or trans due to the high voltage situation....will he be ok if i disconnect the main battery(how do i do that) they are not dummies and have changed plenty of motors and trans for me but never a hybrid
     
    #6 pimpone60, Oct 16, 2008
  7. pimpone60

    pimpone60 New Member

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    i haven't tried the inspection mode but it won't rev up in park right now....do i have to put it in inspection mode to rev the motor in park?
     
    #7 pimpone60, Oct 16, 2008
  8. galaxee

    galaxee mostly benevolent

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    get a stethoscope and pinpoint the source of the noise, instead of guessing. when our es250 engine ate a rod bearing, that thing had a bottom end racket you wouldn't believe. will help you figure out what's up.

    and clear up those misfires first, that's just illogical to ignore.
     
    #8 galaxee, Oct 16, 2008
  9. pimpone60

    pimpone60 New Member

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    i'm gonna fix the misfires tomorrow and do the inspection mode test
     
    #9 pimpone60, Oct 16, 2008
  10. 13Plug

    13Plug Active Member

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    I'm wondering if the problem isn't related to the VVT system. I would get those codes read and see if any are related to that. Perhaps the camshaft/valves get out of whack because a valve timing sensor isn't working. Who knows. This will give you a sampling of what VVT problems entail - OBD-II Trouble Code: P0010 "A" Camshaft Position Actuator Circuit (Bank 1)

    First thing is to get the exact codes read (P0XXX or P1XXX format). You can look up the codes here - OBD-II Check Engine Light Trouble Codes and post back with them. I know you said there were 2 misfire codes but there may be more codes or new codes. Always fix the first codes first (the first ones that show up on the code reader).
     
    #10 13Plug, Oct 17, 2008
  11. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Cylinder #1 is closest to the RH (passenger-side) fender while cylinder #4 is closest to the LH (driver-side) fender.

    The engine is spun by MG1 for several seconds before it actually starts, and it is not obvious when this transition happens. Hence you need to invoke the inspection mode and see what happens.

    If/when you get to the point where you need to replace the engine or the transaxle, I suggest you download the appropriate repair manual info from techinfo.toyota.com as this goes way beyond a brief message that we could post in response to your query.

    If you look for a salvage part, I think you may find that a used engine (which has very low demand) costs less than the transaxle. The transaxle contains the two electric motors, MG1 and MG2.
     
    #11 Patrick Wong, Oct 19, 2008
  12. pimpone60

    pimpone60 New Member

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    i tried the inspection mode thing....shouldn't i be able to rev the engine when its in park? i turned the key on, pushed the accel. twice, pushed brake to shift to neutral, pushed accel. twice, shifted into park, pushed accel. twice, then hit the brake.. the only thing that happens is in the info display is the changes to the warning display and the icon on the right starts flashing..i still can't rev the engine in park...maybe the main battery is low due to only being started and shut off alot and not allowing it to charge...if i was doing it right, let me know...i'll probably try it again but i'll start it in park and let the main battery charge before i do..thanks for the info so far
     
    #12 pimpone60, Oct 19, 2008
  13. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If you see the hybrid vehicle warning icon appear in the MFD after doing the P - N - P sequence, then this shows that you are in inspection mode. At that point, the gasoline engine should start and remain on. When in P, you should be able to rev up the engine to around 2,500 rpm when you floor the accelerator pedal.
     
    #13 Patrick Wong, Oct 19, 2008
  14. pimpone60

    pimpone60 New Member

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    yeah, the hybrid vehicle warning icon is on, but it still won't rev up in park...i'm gonna take it to the dealer tomorrow i guess and let them diagnose it...i'm thinkin the seller might have been right about the gas engine being bad....when i first "start" it in the morning its quiet and smooth...probably because the gas engine is not even running...sounds like it is but its probably just the electric motor spinning the engine...if i take it to the dealer, do you think they can tell me 100% whats wrong with it by diagnosing it?
     
    #14 pimpone60, Oct 19, 2008
  15. morpheusx

    morpheusx Professor Chaos

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    I know this sounds simple but it sounds like a bad ignition coil or two or bad sparkplugs to me. Make sure they are plugged in nice and tight.
     
    #15 morpheusx, Oct 19, 2008
  16. pimpone60

    pimpone60 New Member

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    they are plugged in fine...i was gonna get a couple from advance auto but they are like 80 bucks each(ouch!!!)
     
    #16 pimpone60, Oct 19, 2008
  17. galaxee

    galaxee mostly benevolent

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    swap the coils from the good cylinders and re-run your scanner.

    could be the misfires are the cause of the sound- the springs on the clutch plate are compressing further than they're made to, in response to the engine misfires.
     
    #17 galaxee, Oct 19, 2008
  18. pimpone60

    pimpone60 New Member

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    hey now there's an idea...i'll try that first thing in the morning....wouldn't that be sweet if thats all thats wrong...
     
    #18 pimpone60, Oct 19, 2008
  19. pimpone60

    pimpone60 New Member

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    get this...the dealer called and has my car FIXED!!!! boy did i get lucky...one coil and a set of plugs....340 bucks....said they had another car in the shop they took parts off of to make sure that was my problem and it was so they ordered the coil and sure enough it fixed it...said the knocking noise was the clutch between the engine and trans...it was kicking back on itself when it started missing...springs were bottoming out, etc...i'm still in disbelief that something so simple could cause so much noise..but it was..i drove it home today and its fine...thanks to all that replied and helped
     
    #19 pimpone60, Oct 22, 2008
  20. morpheusx

    morpheusx Professor Chaos

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    Glad it was a simple job and thanks for updating us.

    I had a coil go on the wifes Beetle while I was driving a few months ago, the engine started shaking violently. In VW's they are prone to go out, so many owners leave an old one that was still working in the spare tire compartment for emergencies. Its always a good idea to replace Spark Plugs too in my opinion (might as well you already have the coils off).
     
    #20 morpheusx, Oct 23, 2008
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