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Carbon buildup at <25k miles

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by Lisa99, Dec 27, 2019.

  1. Lisa99

    Lisa99 Junior Member

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    At my last oil change the dealership said I have carbon buildup which needs to be fixed to the tune of $200.

    My prime was bought in July 2018 and is a 2018 model. About 75% of the miles are electric.

    Why would there be carbon buildup or am I getting scammed by the dealer?

    I’m also having a problem with the Ensuite rebooting. It just started doing it about 2 weeks ago so don’t know how it could be a firmware issue that I read about in another thread.

    I’m thinking about buying an extended warranty. My last Prius has zero problems so I’m a bit nervous about letting the bumper to bumper expire at 36k with the issues I’m having.
     
  2. frodoz737

    frodoz737 Top Wrench

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    Can you be more specific about that "carbon buildup" and what the $200 fix was?
     
  3. Lisa99

    Lisa99 Junior Member

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    That was the extent of what I was told. That there was a carbon buildup and that to remove it would be $199. I declined the fix.
     
  4. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    1. Your vehicle needs to be updated in your membership profile.

    2. I do not see how it is possible for an 18 month old car with less than 25,000 miles to have excessive carbon build up ANYWHERE. Even with zero EV use.....

    3. I would never EVER go back to that dealership EVER again, and I would dedicate about 2 days in venting my spleen to Toyota USA, the owners of the dealership, the local BBB, and any Consumer action reporter that I might stumble across in the LV area.
    I would become their social media NIGHTMARE.

    4. This sort of thing happened to me once in 1989. I wrote it off as a scummy dealership.
    Then? Another dealership in another state tried it again.
    They both represented the same manufacturer....and as of 2019 I've never bought another car from that OEM again....even though I drive one every day I'm at work.
    I even post regularly on one of their car's forums. ;)

    @ Extended warranty:

    Why?
    If they're going to knock you on the head for a $200 'non-problem' while the car is still under its BASE warranty - what possible benefit could extending that non-coverage provide????

    Extended Warranties are not usually a wise purchase even when you're dealing with an honest merchant.

    YOU?
    Are absolutely NOT.
     
    #4 ETC(SS), Dec 27, 2019
    Last edited: Dec 27, 2019
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  5. frodoz737

    frodoz737 Top Wrench

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    No documentation? Then nothing is wrong except the Service Advisor bumping the bill...like fuel injection cleaning and blinker fluid. They make a commision off up sells buy the way. It's shady Service Advisors that give ALL Dealership Service Depts. a bad name.
     
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  6. Lisa99

    Lisa99 Junior Member

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    Lol, that’s what I thought. (I’ll update my profile. Need to update my location too but can’t find the edit button on my phone app. We’re driving across country so will do it when we get home.)

    They saw a “girl” and thought easy buck.

    I live in Florida and had to fly to Maryland to buy the car last year so I’m expecting all kinds of weird “service” suggestions since as far as I can tell I have the only Prime in my area.
     
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  7. Lisa99

    Lisa99 Junior Member

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    Thanks for everyone’s advice. I LOVE my Prime and only have one because of this forum.
     
  8. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Tell you what....

    Take the $1200 or whatever they charge for an extended warranty and put it in a CD - or even a checking account.
    READ through your car's warranty and Maintenance guide, and do NOTHING to the car that's not spelled out in that guide without reading through this forum.
    Anything that's not maintenance is a REPAIR.
    Those require a different level of involvement than just throwing your wallet on the counter and begging the service manager to be merciful with you.
    Watch some of the @NutzAboutBolts videos that detail some of these maintenance procedures so that you may become more familiar with what's being done to your car.
    That way?
    When they try to charge you $250 for changing your blinker fluid you will be able to ask THEM questions from a position of greater knowledge.
    Ask questions and read threads in this forum when you're unsure.


    Good Luck!
     
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  9. Lisa99

    Lisa99 Junior Member

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    Wonderful advice!
     
  10. Mendel Leisk

    Mendel Leisk Senior Member

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    There is "carbon build-up", in 3rd gen's, primarily in the EGR (Exhaust Gas Recirculation) circuit, which compromises "cooler", "valve", "pipe", the intake manifold, the intake ports and the intake valves. Exhaust gas is returned to the combustion chambers via all of those.

    Carbon inexorably builds up, and somewhere between 80K and 120K miles gets to the point that cleaning is warranted. Failing to do a cleaning, a couple of things happen:

    1. The "cooler", which has a small radiator fed with engine coolant, becomes carbon coated, and this coating make it less effective at heat transfer, meaning the exhaust gas reaching the combustion chamber is hotter than the engineers had designed for, and combustion chamber temperatures are raised.

    2. All of the EGR components, from the "cooler" to intake manifold, suffer carbon clogging, restricting exhaust gas flow, meaning less exhaust gas than the engineers had designed for is being delivered to the combustion chamber. Again, the result is raised combustion chamber temperatures.

    The outcome of raised combustion chamber temperatures is greater stress on all components of the engine, and what usually shakes out is a head gasket failure. If that is left unfixed long enough, then piston arms can be bent, due to (uncompressible) coolant getting into the combustion chamber. Which can lead to bearing failure, new openings in the engine block sidewall, and so on.

    All that said, that is for 3rd gen. Fourth gen: the EGR design has had a couple of significant changes:

    1. An apparent increase in cross-sectional area of all components, roughly 100%. So the system has much flow capacity.

    2. The intake point for the EGR flow has been moved from upstream of the Catalytic Converter, to downstream. This likely means the exhaust gas entering the EGR system is cooler and cleaner.

    Bottom line: a 4th gen with 25K miles, there's no way carbon build-up will have reared it's head.
     
    #10 Mendel Leisk, Dec 27, 2019
    Last edited: Dec 27, 2019
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  11. sam spade 2

    sam spade 2 Senior Member

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    Likely that there is NO "carbon buildup" and the $200 is to apply $10 worth of something like Techron.

    She is wise to question this scammy behavior.
    And I would recommend finding a different dealer for future service.

    BUT.......if there really IS an abnormal condition showing up, it should be fixed NO CHARGE because it is still under warranty.

    A few dishonest dealers gives them all a bad name.

    P,S. All internal combustion engines have some degree of "carbon buildup" inside the engine and that is not necessarily abnormal and in most cases is NOT a problem either.
     
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  12. Chazman62

    Chazman62 Member

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    Excessive carbon build up on top of the piston would increase compression ratio and can cause knocking or pre ignition. The extent of carbon build up can be checked/seen with a bore scope through the spark plug hole and confirmed by compression check.
    Did the dealer do that?
    Not likely.
     
  13. dig4dirt

    dig4dirt MoonGlow

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    As you know already, any question you can post here and more than likely get the answer.

    Don't get duped by the stealership! :cautious:
     
  14. sam spade 2

    sam spade 2 Senior Member

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    The key word in that sentence is "excessive".
    IF.....the engine is operating "normally", as lean as they run these days there should NEVER be "excessive" carbon buildup anywhere.
    ESPECIALLY with a brand new car.

    If there really is excessive buildup on a car that is still under the bumper to bumper warranty,
    THEN IT IS A WARRANTY CLAIM.

    Maybe anybody who gets this BS story from a dealership should call Toyota directly and ask about the warranty coverage for the $200 cost.
    Maybe that would get somebody's attention. But I doubt it.
     
  15. VickyNie

    VickyNie New Member

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    Carbon deposition really needs to be cleaned up regularly, otherwise, it will cause a lot of problems
     
  16. sam spade 2

    sam spade 2 Senior Member

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    Totally, absolutely and positively NOT TRUE.

    A little carbon deposit is normal and will NOT cause any problems unless it gets to be excessive.
    Which it will NOT do in an engine that is running properly.
     
  17. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    Fortunately, I've never been to a deposition.
    I've also never ever ever seen or heard of a car with less than 25,000 miles with any carbon issues.
    Carbon deposits need only be cleaned when and where they occur.

    Performing this service on a PLUG IN HYBRID with less than 25,000 miles on the odometer (even a Prime) could be the same as putting a toddler on statins (or worse...putting in stents!!) for cholesterol deposits that are not yet present.

    ANY mechanic that would recommend this service at this time, for this car is NOT a mechanic!
    They are a thief!

    Period.
    Full Stop.

    Some....maybe even many mechanics earn a living by providing fair service to customers who cannot or will not do their own repairs and maintenance. An in-law of mine, who is a proud first generation Columbia-American is presently making six figures in a one-person shop whose business in my small town is earned by word of mouth, and to the best of my knowledge he is scrupulously honest, and charges reasonable rates.
    He does this the old way....NOT by jacking money out of wallets but by working 6 half days a week.
    12-hours....is a half day... ;)

    However (comma!!!!) not all mechanics are created equal!!!

    Carbon.
    Mechanics sometimes like to scare the crap out of their victims with a spooky diagnosis of a hard-to-verify problem.
    "Carbon" deposits are a favorite because the only way to VERIFY the presence of this element would involve yanking spark plugs and using a bore-scope....doing a compression test.....yanking the head, etc.
    Most (all) automotive gasoline contain additives designed to remove carbon in places where these deposits are likely to occur.
    BUT(!!) engines are ever evolving....despite claims that these are 'end times' for ICE.

    As of this writing, most every Toyota is port injected.
    Port injection is different than newer Direct injection (or sometimes GFI) which HAS caused resurgence in people using the term carbon build-up with engines in automobiles built in the last quarter century - but it's a different sort of problem in another part of the engine (valves instead of piston tops IIRC) in other makes of cars with HIGHER MILEAGES.

    Explained: Why Some Engines Have Both Port and Direct Injection | Feature | Car and Driver

    Ask the Car Guy: How Can Carbon Build-up Impact My Engine?



    Stern Shot:
    I've even heard of the recent rise in engine deposits in GDI engines being blamed on ethanol....which is an eye-roll best debated in another thread. :D
     
    #17 ETC(SS), Dec 31, 2019
    Last edited: Dec 31, 2019
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  18. vvillovv

    vvillovv Senior Member

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    Another thing that can cause carbon buildup is overfilling the oil. It can be frustrating to find, after an oil change, the dip stick shows there is an extra 1/2 to a quart of oil in the crankcase. But even extra oil in the crankcase would probably not show much carbon buildup in the EVAP system after 25k miles, although it will in most cases reduce gas mileage noticeably. I noticed the other day there is extra oil in the prime and I'm wondering how it got there between the two times I checked it most recently.:rolleyes:
    As the car ages past 100k miles keeping an eye on EGR and other EVAP system components it a good idea, and by than most cars already have noticeable carbon buildup in the EVAP systems. as always ymmv...
     
    #18 vvillovv, Dec 31, 2019
    Last edited: Dec 31, 2019
  19. Hayman66

    Hayman66 Member

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    My dealership told me it was suggested by the manufacturer and they wanted to charge me over 300 for this same thing. Or at least I think it was the same thing all I remember was carbon buildup. I declined. My car only has 21,000 miles on it.
     
  20. ETC(SS)

    ETC(SS) The OTHER One Percenter.....

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    See post #17
     
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