1. Attachments are working again! Check out this thread for more details and to report any other bugs.

Head Gasket Bolt Failure

Discussion in 'Prius c Care, Maintenance and Troubleshooting' started by Just Curious, Jul 14, 2019.

  1. Just Curious

    Just Curious New Member

    Joined:
    Jul 11, 2019
    6
    3
    0
    Location:
    Portland, Oregon
    Vehicle:
    2014 Prius c
    Model:
    LE
    2014 Prius C (75,000 Miles)

    Had a very strange situation occur the other day when my engine temperature sensor turned on and within 2 minutes, smoke started coming out of my engine and loud combustion noises came from underneath the hood. We immediately pulled over and then had the car towed to the dealer. My Prius C is only 4.5 years old but I am out of warranty by 15,000 miles. The dealer who originally said it was a failed gasket... cost $3500. But then received a call from them saying that something else "might" be wrong and that I should pay $550 for them to investigate... and that a complete engine replacement was likely. We took very good care of our Prius - went for regular oil changes and fluid refills and kept on schedule all requested check-ups. With this in mind, we asked Toyota if they would assist since Prius engine failure after four years is not just odd, but likely due to a manufacturer's defect. Not satisfied with Toyota's response and higher repair costs, I went to a local dealer who immediately noticed that one of the head bolts kept turning when they tried to loosen it. They explained that the head bolt had cracked some time ago and that oil and coolant was leaking acutely throughout the engine. Half of the bolt was lodged into the engine and removal would likely deform the engine head. In short, we had to change engine. Took the removable portion of the bolt to a metallurgist who explained that the bolt end was cracked and corroded and likely due to either (1) defect in material (2) long term excess engine heat or (3) original insertion/torque specification failure. Has anyone else experienced this issue with their Prius? Despite an indisputable reputation, even Prius isn't immune to failure.
     
    michael.sfo and Mendel Leisk like this.
  2. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Technically, it's tough luck, but considering the nature of the failure, hopefully you can get Toyota to step up.

    What have they said, so far?
     
    ztanos likes this.
  3. fotomoto

    fotomoto Senior Member

    Joined:
    Apr 22, 2009
    5,596
    3,770
    0
    Location:
    So. Texas
    Vehicle:
    Other Hybrid
    Do a search on Camry 4 cylinder head bolt failures. No pretty but you'll also see some remedies if you don't want to pursue engine replacement.
     
  4. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    10,774
    4,372
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    We need a law against stealersips charging people $500 just to look around and not fix anything. I say triple damages for any criminal who charges that much and doesn't even fix anything!
     
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Maybe a two-level rate: a bit cheaper for diagnostics? I can appreciate time is money, but paying without forseable resolution is frustrating.
     
    PriusCamper likes this.
  6. Georgina Rudkus

    Georgina Rudkus Senior Member

    Joined:
    Sep 15, 2018
    3,096
    2,163
    0
    Location:
    Taylors, SC
    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    It's called being an informed consumer and making a smart choice with your "feet." Simply, noting from the initial finding, an inexpensive compression test was needed, although there may have be a charge for removing the cowl to get to them.

    My choice would be a complete new, used or rebuilt engine.

    Head bolt failure can result from improperly forged or a bad batch of ally used to make them or improper torqueing and installation.
     
    dubit and Just Curious like this.
  7. jb in NE

    jb in NE Senior Member

    Joined:
    Apr 13, 2018
    2,233
    1,595
    0
    Location:
    Nebraska
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium
    It's a free market and nobody is forcing anybody to pay this. If you're in the dealership in the first place, you should have one hand tightly clamped on your wallet.
     
    #7 jb in NE, Jul 15, 2019
    Last edited: Jul 16, 2019
    dubit and Dxta like this.
  8. Georgina Rudkus

    Georgina Rudkus Senior Member

    Joined:
    Sep 15, 2018
    3,096
    2,163
    0
    Location:
    Taylors, SC
    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    In hardening of metals, such as the head bolts, metals exhibit a continuum between ductility and frangibility.

    Ductility is whether the metal is soft enough to be drawn out or stretched. Hardened and quenched steels have a high percentage of martensite resulting in a state that is easily broken by shock, bending or stretching.

    After hardening bolts of steel are tempered at a temperature of 250-450 degrees F over a period of time. This restores some ductility to the bolt which increase it's resistance to shock from temperature and pressure.

    Bolts are like rubber bands, it that, when tightened, they are stretched. An improperly tempered bolt will crack under repeated stress.

    Evidently, the bolts in the OP's engine were apparently improperly tempered.
     
    Just Curious likes this.
  9. jb in NE

    jb in NE Senior Member

    Joined:
    Apr 13, 2018
    2,233
    1,595
    0
    Location:
    Nebraska
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium
    .

    Or over torqued. Or had a pre-existing flaw (a crack or stress concentrator). Or improper material, etc. You can't tell without the failed bolt in hand for examination.
     
    Just Curious likes this.
  10. Just Curious

    Just Curious New Member

    Joined:
    Jul 11, 2019
    6
    3
    0
    Location:
    Portland, Oregon
    Vehicle:
    2014 Prius c
    Model:
    LE
    Thank you JB for your insights. The metallurgist is asking $2500 for a complete investigation of the bold end. A little steep for my situation.
     
  11. Just Curious

    Just Curious New Member

    Joined:
    Jul 11, 2019
    6
    3
    0
    Location:
    Portland, Oregon
    Vehicle:
    2014 Prius c
    Model:
    LE
    Thanks. In the end, we decided to replace the engine.

    Ha ha!! Yes, I felt completely ripped off, so I decided to get my prius towed away from the dealer and fixed for a fraction of the price at a local auto shop with a good reputation.

    Is there any way to get the bolt tested without paying thousands of dollars? If I can prove that the bolt was defective from the start then a small claims suit might be the way to go.
     
    #11 Just Curious, Jul 16, 2019
    Last edited by a moderator: Jul 16, 2019
    Georgina Rudkus likes this.
  12. Dxta

    Dxta Senior Member

    Joined:
    Nov 7, 2016
    1,932
    766
    0
    Location:
    Lagos
    Vehicle:
    2008 Prius
    Model:
    II
    Well, not a Prius though, but have experienced this situation on a Camry 05. Was pretty much overheating and boiling water out.
    Had to removed the bolts.
    I still don't know what caused all that. About 5 bolts were not just tightening the top
     
  13. Dxta

    Dxta Senior Member

    Joined:
    Nov 7, 2016
    1,932
    766
    0
    Location:
    Lagos
    Vehicle:
    2008 Prius
    Model:
    II
    You already are getting another engine. Y wasting that funds to investigate a bolt failure? Are you intent on using the old engi
     
  14. Georgina Rudkus

    Georgina Rudkus Senior Member

    Joined:
    Sep 15, 2018
    3,096
    2,163
    0
    Location:
    Taylors, SC
    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    Try the local university engineering research lab.

    Steel alloys are like an aggregate of crystals of iron, carbon and other alloying elements that are "forged" and heat treated. That process caused the crystals to become very brittle. Tempering reduces some of the stress and "toughens" the

    Hundreds of thousands, even millions of stress cycles of pressure and heating and cooling causes the bonds between the alloying crystals to separate. This cannot be predicted before the bolt is installed.

    In aircraft applications, engines are required to be torn down and examined after a certain number of hours of operation. Metals parts are examined for stress cracks. For steel, Magnaflux is one method of finding stress cracks.Even then, they prematurely fail suddenly before the required rebuild.
     
    Just Curious and Mendel Leisk like this.
  15. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,474
    38,106
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Now I'm scared. :eek:
     
  16. Georgina Rudkus

    Georgina Rudkus Senior Member

    Joined:
    Sep 15, 2018
    3,096
    2,163
    0
    Location:
    Taylors, SC
    Vehicle:
    2012 Prius v wagon
    Model:
    Two
    Neither the Charpy V-notch test or the "stretch" or tensile strength test can predict long term fastener failure. And, the bolt does not have to stressed to the elastic limit to eventually fail. Aluminum is more susceptible to low level repeated stress cycles than steel alloys due to vibration and change in pressurized cabins in aircraft. Like bending metal back and forth, the crystals begin to separate at the crystalline boundaries. It is commonly referred as metal fatigue.
     
    Mendel Leisk likes this.
  17. DonutRobot

    DonutRobot Junior Member

    Joined:
    Jul 16, 2019
    9
    4
    1
    Location:
    Ohio
    Vehicle:
    2013 Prius c
    Model:
    One
    I am looking at a 2013 Prius C to purchase. When reviewing the maintenance history available on the Toyota website I noticed the same issue as you, @Just Curious. It was at 78k miles. The details state: CYLINDER HEAD GASKET ~|~VEHICLE IS LEAKING COOLANT ~|~HEADGASKET LEAKING FOUND HEAD BOLT STREACHED REPLACE GASKET AND BOLTS.
    It was repaired under the Toyota Care Warranty. I haven't purchased this car yet but wanted to share.
     
  18. PriusCamper

    PriusCamper Senior Member

    Joined:
    Mar 3, 2012
    10,774
    4,372
    0
    Location:
    Pacific Northwest, USA
    Vehicle:
    2007 Prius
    Model:
    Two
    Sometimes being an informed consumer and making a choice with your feet isn't an option... When monopolies like Amazon & FB keep destroying the competition and aren't held in check with regulations, consumers get no vote. It's even worse when it comes to competition amongst internet and cable TV providers, once they establish a monopoly and are the only viable option, they can make life very expensive and being an informed consumer becomes irrelevant.
     
    Mendel Leisk likes this.
  19. jb in NE

    jb in NE Senior Member

    Joined:
    Apr 13, 2018
    2,233
    1,595
    0
    Location:
    Nebraska
    Vehicle:
    2018 Prius Prime
    Model:
    Prime Premium
    In the case of automobiles (as was described by the OP), there are other dealers and a plethora of independent mechanics who can do work for you. So, despite your concerns about the state of the free market in general, in this case it is quite easy to vote with the feet. In fact, that's what was done in this case.
     
    dubit likes this.
  20. Just Curious

    Just Curious New Member

    Joined:
    Jul 11, 2019
    6
    3
    0
    Location:
    Portland, Oregon
    Vehicle:
    2014 Prius c
    Model:
    LE
    Impressive analysis!! Thank you.