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found engine oil leak but not sure where it's from

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by working1, Dec 24, 2014.

  1. kitkit201

    kitkit201 Member

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    Ironic that i found this thread today when I went to get a oil change at the dealer. They said it would cost $2400.. i laughed at that and said i'll keep an eye on it. Post #10 is truth
     
    bisco likes this.
  2. A617

    A617 Member

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    Check the oil pressure switch, they seem to have a tendency to leak, its located on the passanger side of the engine, i took mine out, replace it with a new one w/thread lock, no leak so far.
     
  3. PriusCamper

    PriusCamper Senior Member

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    Hi Everyone...

    Looking for PriusChat links for severe oil loss on a 2012 Prius C with only 35K miles on it. I did the oil change on it in early March and everything was fine until a week or two ago when owner discovered the leak. So last night I stopped by and added a little more than 2 quarts to get dipstick to full. Oil drips from bottom off oil pan, but bolt is plenty tight and bolts holding oil pan in place are tight with no leaks.

    There is tiny bit of oil on timing chain cover bolt on the back exhaust side near the top...

    What's most challenging is its such a low mileage engine that it's really clean, and so is the oil so it's not the usual oil leak hunt routine of cleaning the dirt away to track it down. So far everywhere I put my hand is dry other than that one bolt on timing chain cover and bottom of oil pan.

    So I'll be heading back out there this evening to see how easy it is to check oil pressure sensor and and crankshaft sensor and PVC valve. Then if that turns up nothing I might swap the oil filter and possibly event the oil pan, but skeptical that's the fix. There is a tiny amount of barely noticeable corrosion around the oil pan drain plug, but again, that's not the place an oil leak happens despite the fact after engine started there was quickly a drop of oil hanging from under the plug. Any thoughts on what to check?
     
  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Is this car driving or hotel mode? If it's driving and leaking a lot of oil, you'll find it all over the back window and the liftgate.

    If the car isn't being driven, the location of the puddle underneath will give clues as to the leak source.

    You can get some dye to add with oil, then look for it with a UV flashlight. That can help narrow down a leak. Check it before you add the dye in case somebody else already used dye in there.

    No puddle? No oil film all over the back? That usually means the car is burning the oil, not leaking it.
     
    PriusCamper likes this.