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oil change head scratcher

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by Leadfoot J. McCoalroller, Mar 23, 2022.

  1. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I just had the oil filter fall off my c.

    A mile or so from home, got the low pressure warning and stopped immediately to investigate. When it was obvious that I had a major oil leak, I got a ride home and came back with tools. I popped off the plastic belly lid and the filter dropped right out on my hand.

    Ok, that happens when they aren't tight enough, right? So maybe this one wasn't tight enough.

    Except it was tight enough to stay on for the past 3,207 miles since last change, with nary a drop lost.

    And then it fell off. That's really odd to me. I put it on myself, so I've only got myself to blame for choosing that particular one and installing it but it just seems like a very weird failure mode.
     
  2. jzchen

    jzchen Newbie!

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    Too loose, too tight, not sure which happens more. That reminds me that my torque wrenches are my friends....

    (Had a rental Chrysler Pacifica with around 9k miles. Drove home and heard horrible scraping from one of the wheels as I literally pulled up to the driveway. Pulled the wheel off and found one of the caliper bolts loosened so much the brake pad was dragging on the rotor)...

    REVVL V+ 5G ?
     
  3. PriusCamper

    PriusCamper Senior Member

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    Wow, thanks for sharing... Good thing you pulled over right away...
     
  4. Salamander_King

    Salamander_King Senior Member

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  5. PriusCamper

    PriusCamper Senior Member

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    Pretty sure all Prius C are spin on oil filter type...
     
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  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Spec'd install torque is 3/4 of a turn (past first contact) or 13 foot/pounds; did you followed that?

    That said, it is weird: wouldn't you have a major oil leak long before it "fell off in my hands"? I mean even if it was just a turn or two loose, it'd be leaking.
     
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  7. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Aftermarket spin-on. The one I put back on the car today wasn't the same kind as what fell off. Not naming any brands because there's no evidence that it wasn't simply under-torqued; I don't want anyone getting excited with brand wars etc.

    Weird set of circumstances
     
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  8. vvillovv

    vvillovv Senior Member

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    a spin on fallin off in your hand is rare for sure. spin on right? I'd think that there's not much to do in the way of diagnostic either. Kinda like a tire low on air of flat and after pumpin it back up it's good to go for months or years before it happens again, if it happens again.
    I hope at worst it was only a nasty inconvenience and the cleanup wasn't real bad. And no loss of hair from scratching ;)

    edit::
    Salamander_King said: ↑
    Was it spin-on type or element type? OEM or aftermarket?

    Posted via the PriusChat mobile app.
    I'm not seeing Sal's post yet - weird - but it Priuschat !! and I'm gettin used to stuff like that here.

    edit 2::: now I see Sal and P campers posts - wash rinse repeat - it's priuschat again.

    edit 3 - Mendel Liske found this priuschat anomaly 42 minutes ago -now it's 5:50 pm
    Hartle-Hawking State | Page 2 | PriusChat
     
    #8 vvillovv, Mar 23, 2022
    Last edited: Mar 23, 2022
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  9. PriusCamper

    PriusCamper Senior Member

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    Any chance you got an enemy who's tampering with your vehicle? Everytime I unscrew a filter without my oil filter tool but just my hand in a glove about two or three un-turns before it's off it leaks all over the glove and I lose my grip and have a hard time getting it the rest of the way off. Hard to imagine that could come loose without someone intentionally tampering with it?
     
  10. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Well tomorrow I'll have to do some clean-up work under there but I think I should just be thankful that I was able to stop before damaging the engine, and luckier still to do my own roadside recovery without all the time and expense of towing etc.

    I have no direct memory from when I installed it; that was 3000+ miles and a season ago... but I've been doing them approximately like this on lots of cars for decades. I missed something on this one and was lucky to catch it again before it mushroomed into a serious problem.

    The garage floor was spotless when I pulled out this morning. 20 miles later I was on the side of the road.
     
    #10 Leadfoot J. McCoalroller, Mar 23, 2022
    Last edited: Mar 23, 2022
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  11. vvillovv

    vvillovv Senior Member

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    I don't know how long the neck that the filter screws onto is in the C. from what I've seen with the spin ons I change is that once the threads are lined up it takes 25 to 50 full turns before the filter gasket meets metal.

    That would give quite a long time to unscrew itself if it was just loosened up enough to start moving.
    I was gonna ask if you noticed any undercover pins missing or such. But I know I hardly ever check that stuff either when I'm going under the car, unless I'm already suspicious.
     
  12. ChapmanF

    ChapmanF Senior Member

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    Made any enemies lately?
     
  13. Georgina Rudkus

    Georgina Rudkus Senior Member

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    Check for a second gasket. It could be that the original gasket was left on the oil filter adapter which caused the assembly to loosen from vibration and fall off with 3k+ miles driven.

    That's why it's always prudent to check for an old gasket stuck to the oil filter adapter.

    Stripped drain plugs and overfilling is another reason that I do my own oil changes.
     
    #13 Georgina Rudkus, Mar 23, 2022
    Last edited: Mar 23, 2022
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  14. TMR-JWAP

    TMR-JWAP Senior Member

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    Here's an interesting thought. I don't know the specifics of the C, but the cars I know of, the oil pump pushes oil into the outer ring of the oil filter face. Oil goes through the filter element and exits through the center port to flow into the engine distribution paths. I seem to remember most cars have the engine block oil port at an angle going to the filter face. What are the chances this "angled port" flowing oil from the pump to the filter had enough force to make a "semi-loose" filter spin off? May have been lightly torqued and working it's way loose for a while until it hit the breakaway point and then just spun? Just like if I took a stationary fan and sprayed it at an angle with a hose. That fan blade would spin, with the rotation speed determined by the force and angle of the water hitting it.
     
  15. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I went back over everything today and cleaned the bottom of the car, nothing new found.

    I can only guess that I under-torqued the previous filter when I installed it. I don't have a great way to measure the old filter but nothing looked wrong with it. It's still amazing to me that it stayed on the car 3,200 miles.

    When I realized I'd lost all oil my first thought was that somehow the quickchange valve had opened, but it's in the clear.

    I was able to clean up most of the mess with some degreaser and water today, then the carwash to clean the rest. The car ran normally the whole way so I think I've dodged lasting consequences.

    Among the things I learned in the experience:

    • A prius oil pressure alarm can be intermittent, with very long pauses. I was going down a hill on a slow road in the woods, so the engine barely needed to run, and the alarm only comes on when the engine is trying to run. So the hybrid nature of the car made the timing of the problem feel strange.
    • It's ok to trust that fumoto.
    • The oil pressure alarm sounds like 7 or 8 other alarms in the car including the seatbelt and the lane departure warning. Fortunately the video display prints a large clear text message.
    I'm putting the whole thing down to working too quickly when I did the previous oil change. I remember I was trying to get a lot done that day. Middle age has invited me to slow down in many ways, perhaps this is just the latest.
     
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  16. Salamander_King

    Salamander_King Senior Member

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    Thanks for the update. It is really strange how it happened, but now I have to remember that under torquing the filter can happen. I have been reading so many saying over-torqued filter is more of the problem.

    Good to know this. If I keep my PP after my 2 free Toyota Care oil changes, I plan to install Fumoto on it. I already have one installed on our Pathfinder, and it has been working wonderfully. I also plan to re-tap the stripped oil pan drain hole and install a larger bolt size Fumoto on my son's Honda, when the last few threads left in the oil pan give up.
     
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  17. Georgina Rudkus

    Georgina Rudkus Senior Member

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    Everyone claims that spin on oil filters need to only be hand tightened. I never accepted that. I use the method that adds a half to three-quarter turn after contact resistance is felt.

    I've used the Fumoto and the Fram Sure Drain before. Now I just use an aluminum magnetic oil plug, a Viton or HNBR o-ring and tighten it to only about 10 ft lbs. The aluminum threads have half the strength as steel and will give to metal fatigue before the steel.

    The British found that out with the De Havilland Comet in the 1950's. While steel would last almost forever if never stressed to its yield limit, aluminum degrades on the basis of the number of stress loading/unloading cycles many times below its yield limit. That's why over time, aluminum oil pan threads always fail over time with a steel oil plug. An aluminum oil plug would lengthen the time before failure.
     
    #17 Georgina Rudkus, Mar 24, 2022
    Last edited: Mar 24, 2022
  18. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    I will sheepishly admit that I was so concerned that the valve had failed that I carried the original drain plug out there with me when I went to recover the car.

    Very surprised to find it filter-related. But I had one of those in the bag too.
     
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  19. Salamander_King

    Salamander_King Senior Member

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    I have not read a case of Fumoto valve failure anywhere yet. But my guess is that if that is to happen, then it is most likely something on the road hits the protruding valve such that it is physically destroyed. In such a case, I wonder if the thread of the oil pan would stay intact?

    Talking about drain plugs, for my recent oil change on my son's Honda, I had a line-up of the assortment of plugs to choose from. I ended up picking the longest thread plug on the top of the photo below with a Viton O-ring recommended by @Georgina Rudkus. The third one from the top is the OEM plug with aluminum oil pan thread pieces still remaining on the bolt.

    upload_2022-3-24_18-31-37.png
     
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  20. Georgina Rudkus

    Georgina Rudkus Senior Member

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    Wow! I would have tapped it out to M16x1.5 a long time, ago. That's the standard size used by Subarus.

    I'd get this one;

    UTSAUTO Magnetic Oil Drain Plug M16x1.5 Magnetic Sump Drain Nut Aluminum Engine Magnetic Oil Drain Plug for Most Cars with M16x1.5 Threaded

     
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