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2006, 156K miles, recently started bucking when ICE engages

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Michael Jabaley, Jun 20, 2014.

  1. Michael Jabaley

    Michael Jabaley michaelj

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    my 2006 Prius (156K miles) has recently started bucking and jerking when the ICE engages or disengages. The worst is if the car is stopped (brakes or in park) and the ICE kicks in (for instance if the A/C is running) - it will make the entire car jump. But it also happens in the normal course of driving, most often when the car is coasting for awhile and then I accelerate out of the coast - there is a noticeable jump as the ICE engages.

    Any thoughts?

    Thanks!
     
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    When were the iridium spark plugs last changed?
     
  3. Michael Jabaley

    Michael Jabaley michaelj

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    I'll have to go back through the records and look. But if it were the spark plugs, wouldn't the ICE run rough continuously? This is only when starting/engaging.
     
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If the plugs are marginal that might result in the engine taking longer to start than it should, causing the symptoms you described.

    Another possibility is that the fuel line pressure might be slightly low, again resulting in the engine having trouble starting immediately and smoothly. The spec is 44-50 psi when the engine is at idle speed. Five minutes after the Prius is made IG-OFF, the fuel line pressure should be at least 21 psi.
     
  5. Christopher De Leon

    Christopher De Leon Junior Member

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    I have this issue aswell, however my car is a 2009 with only 61k miles on it (Just bought it used 5 days ago). From what I have read so far it is normal for the engine to be a little rough because of the way it is tied into the drive axle. However, I am most certain the roughness I am feeling is beyond normal. I too experience it mostly when sitting idle in the car. I drive for uber, so I spend a lot of time sitting in my car waiting for rides (as I am now). Should a 2009 with 60k need spark plugs already? I thought that was typically a 100k thing, and maybe even more for a prius as the ICE isnt always running.
     
  6. exstudent

    exstudent Senior Member

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  7. writes123

    writes123 Junior Member

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    to evaluate the "usual" hybrid "issues", i would, for peace of mind, test out other 2nd gen prius perhaps at other dealers or carmax etc. as long as they are relatively well maintained you can see what your new car should be acting like. usually the prius is very "smooth" in transitioning. the only rough transitioning hybrid of note is the Nissan Altima hybrid but even then there isn't a hard jerk just a louder ICE noise and engagement. i would definitely get your transaxle fluid changed though. 60k is very optimal change interval.
     
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The normal spark plug replacement interval is 120K miles. However if the engine is running rough, then it is certainly easy enough to remove the iridium spark plugs for inspection.

    Maybe some water got into a spark plug well, causing misfiring. Inspect the plugs and the spark igniters and replace as needed.