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2001 prius sludge issue

Discussion in 'Gen 2 Prius Technical Discussion' started by statultra, Jun 15, 2006.

  1. statultra

    statultra uber-Senior Member

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    i recently changed oil on my 2001 prius, after draining the oil and putting it in my old containers i noticed a extremely thick buildup at the bottom of the container of which i have drained the oil into ( temperatures were about uhh 70 - 80 degrees that day and i ran the engine on inspection mode to warm it up in order to make the oil thinner ) its been about 3500 miles since my last oil change. Last winter i noticed the engine will run rough and seem to have a lot of inertia on the moving parts within the engine ( i could tell by noise of the valves and the feel of the thing basically ), after changing oil with mobil 1 synth, i felt a noticeable change in performance and mpg, also im pretty sure its not the placebo effect, my other 2001 prius that i have has a considerable amount of power and im wondering why this other 01 doesnt. I opted to change the transaxle fluid, i did that and it helped driving performance too ( got rid of a nice power drill noise that used to be coming form there)

    im just wondering anyone ever had sludge problems with their 01?
     
    #1 statultra, Jun 15, 2006
  2. tochatihu

    tochatihu Senior Member

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    I have never seen Prius oil sludge. I understand you got that car "used", and maybe don't know its history. I suggest you also remove the oil pan (buy a new gasket), clean up the inside, and inspect the screen on the oil pump "pickup".

    If your car has been sludged you may need to do a few short-interval oil changes with synthetic, or something else with mucho detergency. Please let us know what you find in there.

    This is an issue near to my heart. Long ago I bought a Honda Civic used, changed engine oil, and thus mobilized a lot of the previous owners' sludge. By making some subsequent mistakes I managed to kill the engine. Let's make sure that you have a better outcome.
     
    #2 tochatihu, Jun 16, 2006
  3. statultra

    statultra uber-Senior Member

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    forgot to mention the sludge actually came from the new prius that i bought in 2000, i have another 01 i bought salvage and it seems to be running in better condition..

    ive been getting misfiring DTC's on the car with the sludge, also a problem is the strange lack of power since 10,000 miles ( of which we thought was normal until we bought the salvaged 01 which was considerably more powerful ) I brought the vehicle in to the dealer about the misfiring and the guys there are money hogs that want me to pay for diagnostic fee, and valve clearance inspection, and stuff. I basically gave up at my local dealer, Hudson toyota.
     
    #3 statultra, Jun 16, 2006
  4. c4

    c4 Active Member

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    There is some sludgy build-up on the bottom of my oil fillter cap of my 2001 Prius, but the internals seem to be quite clean.. I've been using synthetic oil and doing my own engine oil changes since I bought the car 2nd hand, but the previous owner was religious about following the dealer oil change schedule (have all the maintenance records).

    I do notice either some valve-train rattle or perhaps some knock (sounds like a rattling chain) on the car that only occurs for short intervals when you really "put your foot down" and demand power from the engine.. I'm thinking knock vs valve train noise because the noise all but disappears if I use premium gas.. What this has to do with sludge is that it got me thinking initially that if the VVT controller is perhaps not able to move its entire range due to sludge in its passages, but then I remembered that knock is entirely an ignition timing thing, and really has nothing to do with valve timing.. My guess is probably a faulty knock sensor as the car works flawlessly in the rest of its range.. I've been reluctant to take the car into the dealer for diagnosis because looking at the service manuals, for either a valve adjustment or knock sensor replacement, you still have to disassemble the top half of the engine, ie $$$$..
     
    #4 c4, Jun 16, 2006
  5. galaxee

    galaxee mostly benevolent

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    there have been a couple of sludged classic Prius engines that DH has heard of... but it's not inherently prone like the infamous engine sludge issue in the past.

    causes:
    extremely short trips on a frequent basis
    too long of an interval between oil changes
    water contamination in fuel

    at his workplace they keep an eye on the oil cap and if there's any buildup they recommend a shorter oil change interval to prevent sludging.
     
    #5 galaxee, Jun 16, 2006
  6. bwilson4web

    bwilson4web BMW i3 and Model 3

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    <div class='quotetop'>QUOTE(statultra @ Jun 15 2006, 10:49 PM) [snapback]272013[/snapback]</div>
    Did your transaxle oil change include dropping the pan and wiping down all of the surfaces?

    Bob Wilson
     
    #6 bwilson4web, Jun 19, 2006
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