Oil pressure warning despite the oil being full

Discussion in 'Gen 2 Prius Technical Discussion' started by GotToMakeItTo275K, Jan 28, 2020.

  1. GotToMakeItTo275K

    GotToMakeItTo275K New Member

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    I have a 2006 Toyota Prius (Gen 2) with 274K miles. It has an oil pressure warning despite the oil being full. My mechanic thinks the engine rolled a bearing and needs to be replaced. My gut level instinct is that they are right, but I'm interested in confirmation. Note that I know someone who used to work for my mechanic and believes they are honest.

    Also, are there any countermeasures here to at least buy some time? For example, would putting in 10W-40 or even 20W-50 oil still help at this point? 5W-30 is recommended for this model year, although I've been topping it off with 10W-30 when it gets low. Note that temperatures in my area right now are in the 20's and 30's Fahrenheit (so between plus five and minus five degrees Celsius). I don't expect any tricks to buy more than a few hundred miles, but even that would be useful.

    Observations:

    * In mid-December, about 1300 miles ago, MPG suddenly dropped into the 25-30 range. Immediately before that, it was getting in the 36-39 range. (This is consistent with last winter, when it was usually in the 37-41 range).
    * At about this time, I noticed a loud ticking sound from the engine. Over time, it has been getting louder.
    * At about this time, acceleration started to be sporadically weak. Over time, it has been getting even weaker and more consistently so.
    * At about this time, the car stopped liking expressway speeds. It would do it, but the engine sounded and felt horrible, and it often set off my carbon monoxide detector.
    * The car drinks oil at a rate of about one quart per 400 miles.
    * Performance is worse in colder temperatures.
    * Performance and acceleration are noticeably worse on cold starts. They can actually be decent once the car is warmed up (with the proviso that I never take the car on streets faster than 45 MPH anymore).

    There have now been four incidents where the car accelerated poorly from a cold start and, at about 25 MPH, displayed the oil pressure warning:

    1. The dipstick was about halfway between the full and low marks. Topping it off made the warning go away.
    2. 276 miles later, the same as above.
    3. 74 miles later, the dipstick was only about 20% down from the full mark. Topping it off made the warning go away.
    4. 34 miles later, I just had the car towed to my mechanic, who confirms that the oil is full.

    Finally, I've been quoted $6,400 to install an engine with 94K miles. Can I beat this quote significantly? (The shop in question charges dealership prices in a high cost of living area.)

    Thanks in advance!
     
  2. fotomoto

    fotomoto Senior Member

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    This engine may literally grenade itself in the next 100 miles.

    Yes, $6400 is outrageous; shop around. With nearly 300k miles, a complete engine and transaxle swap may make more sense/cents.

    GOOD LUCK!
     
  3. SFO

    SFO Senior Member

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    Welcome to PriusChat!!

    Are there any stored OBD2 codes or warning lights on the dash?

    Sounds expensive. Call some of the local toyota dealers, bet you can find one that will put a *NEW engine* in for that price.

    Or just buy another gen2 for 6400, there must be a decent one available around that price point : chicago cars & trucks - craigslist

    Check the Yelp reviews first, then contact these folks, maybe they can recommend someone to do a used engine swap, or take a look at the 20+ plus prii they have for sale, might even take yours as a trade in - http://www.autoguys.biz or Economical Prius Repair Specialists Including Hybrid Battery Issues - auto parts - by dealer - vehicle automotive car truck sale

    If you do end up buying, before purchase check the VIN at http://toyota.com/owners, and also run your own carfax to be safe.

    @MilkyWay has always been quite helpful, and could have a couple of options for you (y)
     
  4. fuzzy1

    fuzzy1 Senior Member

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    I once experienced something similar to this on a farm motor. Engine stalled twice (after cooling) while idling as if bearings were getting hot and sticking, or other drag was increasing during warmup until it stopped the motor. I thought is was likely an oil problem. Dad insisted that was impossible because the oil was full, which it was. Shop later determined that the oil pump had failed.

    If your engine still runs, I doubt that it has a full oil pump failure. But likely something else is causing oil problems.
     
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  5. sam spade 2

    sam spade 2 Senior Member

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    Yes. But only one.
    Rent a car until you can find a replacement.
    You have a 14 year old car with near to 300K miles.
    It has had a good life. Now it is time for a funeral.
    SERIOUSLY.

    None of the details make the tiniest little difference.
    It is possible that the engine is about to lock up........and/or catch fire.
    Likely even.
    STOP DRIVING IT.

    P.S. And living where you do, the body is probably wracked with "cancer" from road salt.
    I do NOT think fixing it is a wise thing to do.
     
  6. jerrymildred

    jerrymildred Senior Member

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    Oil pump may be the genesis of the problem, but I suspect that the shop is right and the engine has had it. I would not mess with fixing it. Too much $$$ for a car that old. It's had a good long life. Time to put it out to pasture. If not for the expense of towing and the possible inconvenience, it's always kind of fun when an engine sticks a connection rod out through the case.
     
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  7. sam spade 2

    sam spade 2 Senior Member

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    Not if it also locks up solid.........and throws you into a spin. :eek:
     
  8. jerrymildred

    jerrymildred Senior Member

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    I might be wrong, but I think that would only happen with a manual transmission. If I am wrong, then that's part of the "inconvenience" factor. Right along with getting trapped with no power way over in the fast lane.
     
  9. fuzzy1

    fuzzy1 Senior Member

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    I also very strongly doubt that a seized Prius engine will lock the wheels. The HSD between ICE and wheels should be sufficiently flexible to let it roll, maybe even with power still flowing to help reach safe parking.


    When I broke a timing belt on a manual transmission, I had no control problems, but also hit the clutch the moment something was obviously wrong. I had two lanes (but not from fast lane) to move over to the shoulder in heavy evening commute traffic, but the cars behind detected distress and gave me plenty of room.

    Years before, sis had the same event. But her's happened in the fast lane, also in significant traffic. She not only coasted over to and UP the next offramp, but perfectly parked in a safe parking lot as well. The best excuse I've seen for rolling through a stop sign.
     
    #9 fuzzy1, Jan 28, 2020
    Last edited: Jan 28, 2020
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  10. GotToMakeItTo275K

    GotToMakeItTo275K New Member

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    @fotomoto: Not even getting 100 miles wouldn't surprise me. And I'm seeing newer models with fewer miles around here for about half of that $6,400 figure.

    @SFO: The dashboard displays an exclamation mark inside a red triangle. The video screen says, "Problem", and then displays an icon of a dipstick. There are also the following OBD codes:

    * P0446 Evaporative Emission System Vent Control Circuit
    * P1116 Coolant Temperature Sensor Circuit Stack for Coolant Heat Storage System
    * P2601 Coolant Pump Control Circuit Range/Performance
    * P3193 Fuel Run Out

    Some of these predate the oil pressure problem, but really should be fixed regardless if keeping the car.

    The research I've already done turned up Autoguys fairly quickly. Unfortunately, they're not that optimistic about the car and don't seem that interested in buying it. I don't blame them.

    @sam spade 2: I haven't been driving it since the last oil pressure incident. Good point about the road salt - it seems normal when you live here, but it totally changes the calculation on whether an older car is worth fixing.

    All: I agree it's not worth any risk of the engine failing in a way that causes a safety issue. I'm actually leaning towards donating the car as is and calling it a day. The local community college's automotive program has already expressed interest.
     
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  11. scona

    scona Active Member

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    I'm wondering if you should change the oil filter in case there has been a blockage by foreign material. You could cut it open
    to check for debris and see if the oil pressure returns with a new filter.
     
  12. GotToMakeItTo275K

    GotToMakeItTo275K New Member

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    I was actually wondering the same thing. There were metal shavings in the oil the last time it was changed. Could these be getting into the oil filter and clogging it?

    Question is, would the oil filter, by itself, be enough to cause the symptoms noted?
     
  13. valde3

    valde3 Senior Member

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    Metal in oil means that there's something wrong with the engine. Practically it means that you need engine rebuild or a new (or good used) engine.

    Yes a really bad oil filter could cause engine to go bad. But you can't then fix it by putting a good oil filter on.
     
  14. jerrymildred

    jerrymildred Senior Member

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    Agree with @valde3. Any visible metal particles or shavings in the oil filter would indicate that the engine self destruct timer has been initiated. And it's on silent countdown.
     
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  15. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    There is a breakaway clutch between the engine and the planet carrier in the transaxle. I can't say for certain that it exists for this exact scenario; but I can't think of a better reason to put one there. Not unlike a shear pin in a snowthrower. Apart from that, only a rear-wheel-drive vehicle would be thrown into a spin. Granted, an uncontrolled front lockup would be a weird and violent experience but it wouldn't be a spin per se. I could see the torque steer generated by the unequal length driveshafts as being enough to whip the steering wheel hard enough to break a thumb.

    Oil filters have bypass valves, so when the filter media clogs the oil will continue to flow. In many modern cars the filter is operating in bypass mode most of the time the engine is running. Changing filters won't help this engine.

    Hate to say it but everything I've read in this thread says to me that your car is done. Stick a fork in it, not just resting; no longer pining for the fjords, this is an ex-Prius.

    I would not repair it, but I might buy another like it and harvest the good bits off the old one.
     
    #15 Leadfoot J. McCoalroller, Jan 29, 2020
    Last edited: Jan 29, 2020
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  16. edthefox5

    edthefox5 Senior Member

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    Metal shavings in the oil is your 100% confirmation.
     
  17. sam spade 2

    sam spade 2 Senior Member

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    In a conventional vehicle, yes probably.
    With a hybrid vehicle......?????
     
  18. sam spade 2

    sam spade 2 Senior Member

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    That in itself was your first warning of impending catastrophic engine failure.
    The loss of oil pressure was your second.
    The rest of this discussion is just a waste of time.

    Three strikes and you are OUT.
    :eek:
     
  19. jerrymildred

    jerrymildred Senior Member

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    I can't say for sure how the Prius would respond to a seized engine at speeds higher than MG1 can be spun. @Leadfoot J. McCoalroller mentioned a possible breakaway clutch. I haven't heard that the Prius has one and the descriptions by Professor John at Weber State don't mention one. It might just destroy the transaxle by spinning it too fast unless it's a Prime with the sprague clutch. Whatever happens, I think it might make for an "interesting" day.
     
  20. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I'm pretty sure I first learned about it in one of those Weber videos. I found a reference to it with photo here, just now. We know it isn't like a traditional clutch because there is no pressure plate or release mechanism; but I can't tell if it is supposed to provide a strain relief in the event of a lockup or if it is strictly a damper for NVH reduction.

    The comment on that site:
     
    #20 Leadfoot J. McCoalroller, Jan 30, 2020
    Last edited: Jan 30, 2020
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