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ICE Coolant Contaminated. Little worried.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by AzWxGuy, Sep 15, 2013.

  1. AzWxGuy

    AzWxGuy Weather Guy

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    I was doing my usual bi-monthly oil change this morning, and since I just passed through 150K miles I spent some time checking out the various other systems in the car. When I came to the ICE cooling system, I might have found a problem. A little history first. I replaced the ICE water pump myself at 71K miles in July 2011. I drained the coolant, replaced the pump, and since the coolant looked perfectly good (nice pink color, no suspended particulates) I put the used coolant back in. Made it easy to eliminate all the air that way. Then in June 2012 at 108K miles I had the dealer drain and replace both the ICE and inverter coolant. Might have been done in conjunction with a 100K service. So today, I removed the radiator cap and take a look down there and I'm seeing some strange colors.

    DSC02237.JPG

    It looks orange and a bit milky. The fluid in the overflow reservoir is the typical pink, clear fluid so it either just happened or the cooling system doesn't ever heat up enough to expand into the overflow tank. Several things come to mind. Oil contamination for one. I don't know what SLLC with oil in it would look like. There was no evidence of coolant in the oil I just drained. So the chances of it being some sort of head gasket failure seem remote. Engine performs well, nice smooth acceleration curve, no "white smoke" in the exhaust. The only other thing I can think of that might be pertinent is, when I replaced the ICE water pump I noticed there was like a quarter inch stripe of orange paint on one of the impeller blades of the new pump. Something from the manufacturing process perhaps. I wouldn't think that small bit of paint would suddenly decide to dissolve and be of sufficient quantity to color the whole coolant charge. I will probably go ahead and drain and replace the coolant here soon to see if the problem persists. Just wondering if anyone else has any suggestions.
     
  2. wjtracy

    wjtracy Senior Member

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    I can't tell from the pic, but if the oily material is just on the top I would to clean it from the top, eg; with paper towels or maybe old turkey baster to suck out the top oily liquids, maybe several times.

    Once I accidentally put a couple of glubs of motor oil my washer fluid (other car not Prius). I was able to absorb the oil off the top of the fluid with rolled up paper towels.
     
  3. bisco

    bisco cookie crumbler

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    are you losing any oil between changes?
     
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  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    That is an excellent idea. My first thought given the opaque quality of the fluid is that the coolant is contaminated with engine oil. When the coolant is drained, see what the inside of the radiator, as visible from the radiator neck opening, looks like. If it has oily deposits within, that would be more evidence of oil in the coolant.
     
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  5. AzWxGuy

    AzWxGuy Weather Guy

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    That was my first thought also. But no oily residue on the exposed surfaces of the radiator cap, which is usually a dead giveaway. Dipped a paper towel in the radiator neck opening and nothing "floating" on the surface nor any oily feeling to it. Oil usage has remained stable since I switched to Valvoline High Mileage 5W30 five oil changes ago, just about a quart in 5000 miles. I would almost think it was rust, hope not though. How long does "Super Long-Life" coolant last anyway? At least 100K miles according to the Scheduled Maintenance Guide. Maybe someone else can "visual" this out for me. In the mean time, I'll have it changed out. I think a trip to the dealer, who changed the fluid at the 108K mark, would be best. Maybe they have an explanation.
     
  6. bisco

    bisco cookie crumbler

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    would an oil analysis tell what's in it?
     
  7. wjtracy

    wjtracy Senior Member

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    I do not have too much experience with oil in the antifreeze but it could be emulsified which might cause the milky color.
     
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    The service interval is 50K mile intervals, after the initial change at 100K miles.

    It is reasonable to have the service dept tech look at the fluid. Which dealer did the service: Precision or Desert?
     
  9. AzWxGuy

    AzWxGuy Weather Guy

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    It was Desert.
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I have more confidence in the Precision service department.
     
  11. AzWxGuy

    AzWxGuy Weather Guy

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    Upon closer inspection, actually withdrawing a sample, it looks like all is well. Fluid is "in the pink" and clear. Must have been some curious function of the light or radiator filler tube to give it that orange tint. I should have pulled a sample that day, but I was running out of time. Anyway, disaster averted. I will take that recommendation Patrick to do (or get) another drain and fill. I imagine this applies to both cooling loops, ICE and inverter. Hmm, to DIY or dealer service. Reading about problems with trapped air isn't very encouraging. Especially the inverter circuit. Then, what to do with 3+ gallons of used coolant. Isn't as easily recyclable as engine oil. Might just spring for the dealer service and be done with it. All in a days work.
     
  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Actually the 2G inverter coolant loop is relatively easy to purge the air out (compared to Classic) but the 2G engine coolant loop is fairly difficult due to the CHRS canister.

    Regarding the used coolant, just take it to your local dump in Tucson for household hazardous chemicals recycling. This is what I do in Sahuarita.