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

Rough start after extensive cleaning and replacement parts

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by run4priz, Aug 31, 2021.

  1. rjparker

    rjparker Tu Humilde Sirviente

    Joined:
    Jun 6, 2008
    7,471
    4,373
    7
    Location:
    Texas Hill Country
    Vehicle:
    2012 Prius v wagon
    Model:
    Three
    I have heard mixed reviews about piston soaks but some mechanics say it helps. Just be sure you don't hydrolock a cylinder by electrically spinning the engine before the chemical is removed or leaks into the crankcase.

    Borescope pics with a cylinder coolant leak usually show a much cleaner piston. All yours seems to show is excessive carbon buildup. I would be surprised if the engine did not ping occasionally, especially on regular.

    The bottom line question: Has it rattled on start up since your post cleanup episode?
     
    #21 rjparker, Sep 6, 2021
    Last edited: Sep 6, 2021
  2. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Wedging a breaker bar and holding it to ensure it didn’t move or slam into something was what i did. I resorted to having it point upward. My breaker bar was not long enough to point downward and reach with my foot. It might not have technically been a breaker bar. It was a non-ratcheting 1/2 drive, about twice as long as most 1/2 ratchets you’d get in a set, but not as long as some of the pics I’ve seen illustrating various items. I think the readings i have a pretty good. I used a wooden dowel that i marked the top location on one of the cylinders. Once i determined which one of the cylinders was was in the up position i then determined easily which one was in the compression stroke vs power stroke. I then went from than cylinder to the next one in the firing order after rotating that next piston to the top of the cylinder.

    I read in another thread somewhere that the prius valves are a little finicky to determine exactly where both are closed due to the narrow window between compression and power.
     
  3. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Hi RJParker. In answer to your question about any further rattles on start up, yes. For about a sec or so and then would stop. Nothing like before where it would do it for 20-30 seconds or longer.

    Definitely will make sure cylinder is clear of liquid before starting back up.
     
  4. Rebound

    Rebound Senior Member

    Joined:
    Mar 11, 2010
    3,961
    2,609
    0
    Location:
    Portland, OR
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    Yes! That definitely happened to me once, after doing a complete intake manifold clean/EGR cooler swap/oil catch can install. It ran really bad at first startup. We killed the engine, started again, and it's been fine ever since. Lesson Learned: I disconnect the 12V battery before disconnecting those engine sensors. Since then, haven't had such problems after doing this work. At any rate, YES, I've had the exact same thing happen and it hasn't been a problem. (It wasn't my car, but the owner didn't report any problems after a year).

    Have you ran a code reader again? What codes, if any, do you get now?
     
    Raytheeagle likes this.
  5. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,467
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Outa my depth, but I heard (Eric the Car Guy video) that for leak-down it has to be at TDC AND on the compression stroke. He had a trick for determining that.
     
  6. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Hey rebound, thx for the reply. Just sent the car back with my son. No codes. Generally running well. Rattles briefly at start up but then goes away about as quickly. Still a little puzzled by that one. I guess I would expect another CEL if it was an actual misfire. Still not seeing coolant leaks and really cleaned the EGR valve and cooler well. I may have him run a few takes of higher grade gas to see if that has any affect.

    The rattle is not anywhere close to the level previously experienced. We’re going to monitor the oils consumption of the next 1,000 miles and see how it goes. I’ve got him laser focused on it now. Running seafoam in the gas and then running MMO in the crankcase. MMO is much cheaper so finishing out the last of the seafoam. Hopefully no more CEL’s for a bit. I think I’ll take a peak at the pistons again when he brings it back.

    I’m guessing new piston rings are probably warranted at some point. Not sure I’m ready to tackle that one yet. But may be close…working on another family members car this weekend which may push me even closer to that task.

    thx Mendel, I’ve watched a few of his. I think his trick was a screwdriver if it’s the same video of the Chevy Tahoe or suburban. I personally like the wooden dowel. DIY Dave had a good trick for marking TDC on the dowel, which is what I did. Unless there’s something to the Atkinson cycle in the Prius affecting where TDC actually occurs, I think I found it.
     
    Mendel Leisk likes this.
  7. Rebound

    Rebound Senior Member

    Joined:
    Mar 11, 2010
    3,961
    2,609
    0
    Location:
    Portland, OR
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    I think you should check the vehicle codes as soon as possible.
    You could be getting codes even though you aren't getting a CEL. And, you need to be very careful when reading codes. 99% of people think the code tells you what's broken. They do not. They tell you that one or more sensors have detected a value out of range. That's just the beginning of a diagnosis, not the end.

    A classic example is an O2 sensor error message. You will get this error almost any time the car is running too rich or too lean, which can be caused by pretty much anything. So people replace the expensive O2 sensors, clear the code, it's gone! ...and then the code comes back, because the problem was never fixed in the first place.
     
    run4priz and ASRDogman like this.
  8. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Looks like we’re back to the possibility of a blown head gasket. Noticed the coolant was all of a sudden low. A couple of short start-up rattles but no CEL. No white smoke or discoloration in oil. Possible it just a minimal head gasket issue at the moment (if there’s such a thing)? Are white smoke or discoloration not always a given when a head gasket fails?

    Going to double check for any other obvious coolant leak possibilities, but planning to do a head gasket replacement this weekend. Everything seems to generally point to it.

    BTW, oil consumption has dropped since the other work. Close to 2k miles before having to add oil. Normally would have been 600 miles or so.
     
    Mendel Leisk likes this.
  9. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,467
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    Part numbers for head bolts and Toyota gasket kit (has head gasket, and pretty much every other pliable item you'll take off, if I'm not mistaken) in the attachment. Toyota recommends 12mm double hex bit for the head bolts.

    Some of the links in my signature will be helpful. Besides the obvious head gasket ones, the EGR link has torque values that'll be of use.
     

    Attached Files:

    #29 Mendel Leisk, Nov 1, 2021
    Last edited: Nov 1, 2021
    run4priz likes this.
  10. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,467
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
    This video is a good overview:

     
    run4priz likes this.
  11. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Thx Mendel. I found that video over the weekend and gave me enough info/confidence to tackle it myself.

    Also, thx for the part #. I had narrowed it down to that on as well. Thx again!

    Here's to a positive experience this weekend...and not issues on the head bolts.
     
    Mendel Leisk likes this.
  12. Rebound

    Rebound Senior Member

    Joined:
    Mar 11, 2010
    3,961
    2,609
    0
    Location:
    Portland, OR
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    A blown head gasket will almost always do one of three things:
    Leak into the exhaust
    Leak into the intake
    Leak into the coolant
     
    run4priz likes this.
  13. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    Appreciate all of the feedback on this.

    This car is my son’s so trying to help him out with the repairs and teaching some maintenance along the way. First car for him to own. The gasket kit / new head bolts…OEM, about $260.

    I was also doing some checking on cost of a replacement engine…just for comparison purposes. Cost of a replacement engine (long block, used, not rebuilt), found one with 73k miles for $2500 and one with 26k miles for $3200, delivered from wherever to GA, no core charge. Both come with 6 month warranty. Confirmed US sourced and not JDM. Thoughts on these? These seem a little on the high side based upon other posts I’ve seen.

    178k miles on current one. My math says try the $260 repair first and see if / how long that helps. Based upon everything we’ve found so far, the piston rings are worn out, given the oil consumption issues we were originally having.

    We’re doing all of the work ourselves.
     
  14. Rebound

    Rebound Senior Member

    Joined:
    Mar 11, 2010
    3,961
    2,609
    0
    Location:
    Portland, OR
    Vehicle:
    2012 Prius Plug-in
    Model:
    Plug-in Base
    When you replace a head gasket, you don’t know what you’re dealing with until the cylinder head is off. You have to take the head to a shop to be tested and probably machined, and you have to check the pistons to ensure they’re all flat at TDC, to ensure no rod or bearing damage occurred.

    There’s always a possibility that the problem is more than a head gasket.
     
  15. Mendel Leisk

    Mendel Leisk Senior Member

    Joined:
    Oct 17, 2010
    54,467
    38,101
    80
    Location:
    Greater Vancouver, British Columbia, Canada
    Vehicle:
    2010 Prius
    Model:
    Touring
  16. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    As a conclusion to this thread, here’s an update on what we did and how it turned out:

    we replaced the head gasket with OEM gasket set, which had gaskets for most other parts: changed gaskets on tensioner, water pump, thermostat, EGR, and top engine cover.

    All went well, until we broke a camshaft assembly bolt. We ended up getting sealant in one of the bolt holes. My conclusion was that that affected our ability to properly torque the bolt or rather allowed for over torquing. We replace that bolt and a couple of additional ones where threads looked like they we stretched.

    abilty to get parts was challenging. Dealers were limited on stock. Had to use a regular bolt and washer rather than the flanged OEM style for one of them.

    Upon reassembly we cross threaded a bolt that fastens engine mount to fender well. We fixed that with that with no issue.

    after start up, we had a significant leak at the chain tensioner. After reading several threads we put the engine at TDC and removed, applied a thin layer of sealant and reinstalled and ensured it was properly torqued. Leak fix…for now. (Also notice this was present before we did any work. So it was an existing issue.

    threw P0351-P0354 on start up. Although these all reverted to inactive permanent codes. My conclusion is that since inactive and not pending or current were good.

    Will the permanent aspect go way after drive time is experienced?

    thanks for all of help on this. It was quite a journey and very satisfying to have fixed this issue.
     
    Mendel Leisk likes this.
  17. xliderider

    xliderider Senior Member

    Joined:
    Apr 19, 2012
    7,842
    3,099
    0
    Location:
    Honolulu, HI
    Vehicle:
    2011 Prius
    Model:
    Three
    Good job, sounds like quite the journey.

    If I went through all that, I might've done a piston soak with Berryman's B12 to decarbonize and free up the piston rings. That would hopefully take care of or help with the oil burning issue.

    Did you have a machine shop check/machine the heads?

    Posted via the PriusChat mobile app.
     
  18. run4priz

    run4priz Junior Member

    Joined:
    Aug 26, 2021
    20
    7
    1
    Location:
    Atlanta
    Vehicle:
    2012 Prius v wagon
    Model:
    Five
    I did do a seafoam soak again for a couple of days while we were working on other things but didn’t do Berryman B12…what’s your thought on Berryman vs seafoam? This was also done a couple of months ago as well and we noticed some marginal improvement.

    Do to timing and logistics, we opted against the machine shop this go round. I would have preferred to not do that but we were very limited in time. Definitely a gamble but after checking for flatness, Nothing appeared warped. We also checked the valves for any leaking. Everything appeared good there too.

    we ended up using Toyota’s seal packing rather than Permatex. Seems like it had a faster cure time.
     
    xliderider likes this.
  19. Peter123

    Peter123 Active Member

    Joined:
    Oct 30, 2018
    130
    126
    1
    Location:
    Los Angeles, CA
    Vehicle:
    2011 Prius
    Model:
    Two
    You can clear the permanent codes with techstream or with some of the other odb2 tools. After you do that the car will report that it is not ready for a smog test even though there are no current codes. You will then have to drive the car several hundred miles. After all of the system tests go through a complete cycle without throwing an error, it will report as ready for testing. At that point not having codes is a pass.
     
  20. James Finch

    James Finch Junior Member

    Joined:
    Jul 7, 2021
    69
    12
    1
    Location:
    Whitehall, Mi
    Vehicle:
    2013 Prius
    Model:
    Two
    i see where that's about the only oil consumption reduction chemical treatment that's been significantly effective for DIY Dave in his series.

    What's the latest and greatest regarding performance, after your repairs?