Gen 3 Valve Seals - The Definitive Source of Oil Burning?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Pollymath, Sep 28, 2020.

  1. Pollymath

    Pollymath Junior Member

    Joined:
    Mar 4, 2020
    64
    32
    0
    Location:
    Flagstaff, AZ
    Vehicle:
    2010 Prius
    Model:
    II
    I know there are few people on this board who replaced their valve seals in an attempt to cure oil burning issues.

    My 2010 Prius burns oil like nobody's business. Like, a quart every 1000 miles. Maybe more.

    I've seen theories that this might be due to the coked up and carbonized "stuck" piston rings, but before I go blowing $75 on Valvoline Premium Blue Restore, I thought I'd check to see if the valve seals solved other peoples problems with oil burning.
     
    #1 Pollymath, Sep 28, 2020
  2. Pollymath

    Pollymath Junior Member

    Joined:
    Mar 4, 2020
    64
    32
    0
    Location:
    Flagstaff, AZ
    Vehicle:
    2010 Prius
    Model:
    II
    Bump?
     
    #2 Pollymath, Oct 9, 2020
  3. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    2,678
    1,709
    0
    Location:
    Indian River County, Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    There has been non update, yet, of the few that have replaced there head gaskets and
    valve guide seal at the same time.
    I guess they have not put enough mileage on it yet.
    I personally believe the seals are the biggest cause from experience with other engines.

    I think we are all waiting to hear an update...
     
    #3 ASRDogman, Oct 9, 2020
    mikey_t likes this.
  4. Pollymath

    Pollymath Junior Member

    Joined:
    Mar 4, 2020
    64
    32
    0
    Location:
    Flagstaff, AZ
    Vehicle:
    2010 Prius
    Model:
    II
    Any ability to squirt some sort of seal softner/conditioner directly on the valve seals, let it sit, and see if the oil consumption decreases afterwards? Even if it doesn't fix cracked/broken seals, it might be enough to identify the problem.

    Somewhere I noticed someone mentioned the relationship between the OCC and PCV. Like, if you OCC wasn't filling up, then maybe you had a PCV issue or vice versa. My OCC is very slow to fill up, despite burning 1qt every 800-1000 miles.
     
    #4 Pollymath, Oct 9, 2020
  5. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    2,678
    1,709
    0
    Location:
    Indian River County, Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    Oil get sucked into the cylinder then burned.
    The seals get hard and brittle. Once they get hard, you can't soften them up.
    You just have to replace them.
     
    #5 ASRDogman, Oct 9, 2020
  6. Pollymath

    Pollymath Junior Member

    Joined:
    Mar 4, 2020
    64
    32
    0
    Location:
    Flagstaff, AZ
    Vehicle:
    2010 Prius
    Model:
    II
    I know how valve seals works and why their failure burns oil.

    To be fair, that's the entire point of seal swell in high mileage oils.

    And, personally, I have seen results from products that claim to make seals more malleable, even once they've been dried and hardened. It doesn't restore them to new, but it does do something.

    Again, the point is merely to use it as a quick and easy determination. I don't want to replace the seals only to find them in excellent shape. It's a PITA process. Then again, by the time I squirt some wonder-lube on them, I'm half way to replacing them.


    I'm still curious if there is a relationship between OCC levels and PCV valve condition.
     
    #6 Pollymath, Oct 9, 2020
  7. ASRDogman

    ASRDogman Senior Member

    Joined:
    May 29, 2018
    2,678
    1,709
    0
    Location:
    Indian River County, Florida
    Vehicle:
    2010 Prius
    Model:
    Two
    I have water front property in south Florida really cheap if you're interested.....

    You are free to try whatever you want.
     
    #7 ASRDogman, Oct 9, 2020
  8. Rebound

    Rebound Senior Member

    Joined:
    Mar 11, 2010
    3,715
    2,328
    0
    Location:
    Portland, OR
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    The valves and the heads are machined to perfect tolerance to seal. It’s not about being soft or hard; it’s not some kind of gasket or soft material.

    MAYBE you can have some cooked-on deposits which prevent perfect seal. But considering the temperatures and pressure that cooks that stuff on, no magic oil is going to get rid of it.
     
    #8 Rebound, Oct 10, 2020
  9. Pollymath

    Pollymath Junior Member

    Joined:
    Mar 4, 2020
    64
    32
    0
    Location:
    Flagstaff, AZ
    Vehicle:
    2010 Prius
    Model:
    II
    No I meant a top end oil of some sort. Essentially getting some sort of conditioner on the top side of the valves and letting it sit.

    Either way, seems like by the time Im that far into it I might as well go all the way.

    I’ll try thicker high-mileage oil, first.
     
    #9 Pollymath, Oct 11, 2020
  10. mikey_t

    mikey_t Active Member

    Joined:
    Feb 5, 2019
    209
    240
    0
    Location:
    Los Angeles
    Vehicle:
    2010 Prius
    Model:
    Two
    Have you tried the BP treatment of 44K, EPR, and and MOA? They helped alleviate some of my 2010's oil burning after the first run, and I use the EPR/MOA with every oil change now, the 44K once a year.
     
    #10 mikey_t, Oct 11, 2020
    Raytheeagle likes this.
  11. Raytheeagle

    Raytheeagle Senior Member

    Joined:
    Jul 1, 2016
    10,600
    14,468
    0
    Location:
    Bay Area, California
    Vehicle:
    2019 Prius Prime
    Model:
    Prime Plus
    Good to hear it is still working :).

    How many miles you up to now:whistle:?
     
    #11 Raytheeagle, Oct 11, 2020
  12. PriusTheGreenest

    PriusTheGreenest New Member

    Joined:
    Oct 9, 2020
    1
    0
    0
    Location:
    San Francisco Bay Area
    Vehicle:
    Other Non-Hybrid
    Model:
    N/A
    I'm in the market for a Gen 3 Prius. It appears the Gen 3 years 2010-2011 are the worst impacted years for poor seals/blown head gasket issue.

    Although it sounds like Gen 3 years 2012-2015 have less of this issue occurring, can anyone confirm if this issue was completely resolved for Gen 3 years 2012-2015 or just occurs less frequently?
     
    #12 PriusTheGreenest, Oct 11, 2020
  13. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    40,842
    29,319
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    I doubt there's much difference. Sometime thru model year 2014 the pistons and rings were revised; that's all I've heard/gleaned. Oh, and EGR valve, and intake manifold had revs, at some point, but don't see that changing oil consumption.
     
    #13 Mendel Leisk, Oct 11, 2020
  14. mikey_t

    mikey_t Active Member

    Joined:
    Feb 5, 2019
    209
    240
    0
    Location:
    Los Angeles
    Vehicle:
    2010 Prius
    Model:
    Two
    I haven't driven much at all this year b/c of Covid, but I'm around 162k miles. I might switch over to 5W-30 oil at my next change though, as last time I checked it seemed like the burning was picking up again.
     
    #14 mikey_t, Oct 11, 2020
    Raytheeagle likes this.
(You must log in or sign up to post here.)
Loading...
Similar Threads - Valve Seals Definitive
  1. Cierra

    Help! Loose Bleeder Valves?

    Cierra, Aug 31, 2020, in forum: Gen 3 Prius Care, Maintenance & Troubleshooting
    Replies:
    1
    Views:
    382
    Kenny94945
    Aug 31, 2020
  2. ThatDudeOnChestnut

    2010 shaking in reverse

    ThatDudeOnChestnut, Aug 12, 2020, in forum: Gen 3 Prius Care, Maintenance & Troubleshooting
    Replies:
    15
    Views:
    1,483
    ThatDudeOnChestnut
    Aug 22, 2020
  3. pingd

    Inserting new spark plug tube seals into the valve cover ... anything better than beat them in?

    pingd, Oct 12, 2019, in forum: Gen 3 Prius Care, Maintenance & Troubleshooting
    Replies:
    25
    Views:
    3,973
    Mendel Leisk
    Oct 26, 2019
  4. pingd

    Valve Cover Spark Plug Seals, Removal Tips?

    pingd, Oct 11, 2019, in forum: Gen 3 Prius Care, Maintenance & Troubleshooting
    Replies:
    4
    Views:
    795
    pingd
    Oct 12, 2019
  5. Mola

    valve stem seal DIY

    Mola, Apr 6, 2018, in forum: Gen 3 Prius Care, Maintenance & Troubleshooting
    Replies:
    102
    Views:
    12,434
    T1 Terry
    Aug 17, 2020