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Gunky Oil -- what is it? Is it anything?

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by cyberpriusII, Mar 22, 2013.

  1. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    Had car in for water pump recall on Monday.

    Changed oil today. Put maybe 55 miles on since the water pump work.

    When I pulled the oil drain tub out from under the car, noticed a clump of yellowish/white gunk, more of a streak than a clump. Not too big -- hmmm....maybe a third of the width of a number 2 pencil and about as long as a US 25-cent piece. Maybe as thick as a dime.

    Wondered about it, but I store the oil drain tub where mice and rats have wild parties, so....

    Changed oil, pulled out dipstick to check and noticed a little bit of this yellow film along the dipstick. Not any thickness to it, but pretty much the length of the "quart marks."

    A little baffled and a little wary, I went ahead and did a 10 minute test drive, let the car sit for about 30 minutes and then checked the dip stick. Oil level fine, no streaks.

    BTW, checked oil last weekend, before taking it for recall work, did not notice anything at that time.

    I guess I could have imagined it, but am wondering. Anything come to mind at all?
     
    #1 cyberpriusII, Mar 22, 2013
  2. SteveLee

    SteveLee Active Member

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    The possibilities that come to mind are:
    1.Water in the oil either from condensation due to mostly short trips in cold weather that does not allow for the condensed moisture to burn off, or a leaking head gasket allowing coolant into the oil.
    2. Over-filling the oil.

    The amount is more indicative of condensation. If so, it will likely get better with warmer weather and longer trips. Do you typically drive short distances?
     
    #2 SteveLee, Mar 23, 2013
  3. css28

    css28 Senior Member

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    It does sound like moisture in the oil (forms sort of an emulsion).

    Search the forum for PCV valve information. PCV stands for positive crankcase ventilation. If the PCV valve isn't functioning properly it can cause unnecessary moisture buildup inside the sump.

    As far as warming up is concerned, that has be a downside of hybrid vehicles like this. On my 20 mile commute this time of year the coolant doesn't reach operating temperature until I get on the freeway. Oil temperature generally lags coolant temperature so I doubt my oil has gotten profoundly hot since my last extended drive (over an hour).
     
    #3 css28, Mar 23, 2013
  4. css28

    css28 Senior Member

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    Search completed.
    Here's how to replace the PCV (involves removing the wiper module, among other things):
    PCV replacement how-to with photos | PriusChat

    If you read the discussion that follows, two things become apparent:
    1) You can probably effect the change without removing the wiper module.
    2) When you get to it you'll probably find that the PCV valve is just fine.

    I'd recommend that you leave things alone for now. I have a 16 year old BMW that I bought when it was three years old. Shortly after bringing it home I discovered to my horror some yellow gunk on the underside of the oil filler cap. 13 years and 100,000 miles later the car's just fine. As long as you use high quality oil and change it at the recommended interval you should be fine.
     
    #4 css28, Mar 23, 2013
  5. wjtracy

    wjtracy Senior Member

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    What type of oil are you using?
     
    #5 wjtracy, Mar 23, 2013
  6. cyberpriusII

    cyberpriusII Prodigyplace says I'm Super Kris

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    Hi Folks:

    As always thanks to all of you for your helpful and intelligent replies!:)

    I was a bit worried about head gasket, since I had an old corolla that it seems I saw the same thing with, only more so....can anyone say "hydrolock."

    It has been extra cold around here lately and lots of moisture -- set a precipitation record a day or so ago.

    And I have only been driving about 10 minutes a day for the past week or so....5 minutes in the morning and another 5 in the evening. Normally, I would bike or walk that, but it is COLD and I am recovering from a foot issue....

    So, at 50K, I am hoping for the "cold condensation" to be the issue -- or should I say non-issue!

    So, I think I will do what I like best, nothing!(y)

    As for oil. I am not certain what I used in September. It was probably NAPA 5w-30 (or whatever viscosity Toyota calls for). It could have been Valvoline or Quaker. I just put in Castrol. I buy what I can get for $3-ish per quart as long as it is a reputable brand. Oil filter was a Carquest Blue. I just put on a NAPA Silver ($3.40 on sale).
     
    #6 cyberpriusII, Mar 23, 2013
  7. wjtracy

    wjtracy Senior Member

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    May I suggest synthetic oil
     
    #7 wjtracy, Mar 23, 2013
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