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Thread: Head Gasket Failure

  1. #1

    Default Head Gasket Failure

    Hi,

    that's why i used NSXprime to store all my NSX photos, right up until it stopped
    allowing uploads to our personal gallery and only as attachments.

    Because of this, and also because the nsx is waiting that i fix the leaking headgasket,
    i stopped any updates to my thread until i manage to have my own site.

    A shame, but it is what it is

    Nuno

  2. #2
    Join Date
    Dec 2007
    Location
    Switzerland
    Posts
    1,006

    Default

    Quote Originally Posted by UnhuZ View Post
    leaking headgasket
    Hi Nuno

    What happened?

  3. #3

    Default

    Hi Thomas,

    remember my never ending quest chasing coolant leaks ?!

    well... it ended... with a blown head gasket a little over 4 years ago.

    after replacing everything in the coolant circuit, ence building pressure for
    the next eak link to go kaboom, my oem radiator broke on the bottom fins,
    and that together with traffic made my eyes go out of the temp gauge for
    more than usual and for sure, when i looked back, the temp was in the red.

    i repalced it with a used oem one, tested under pressure, but then i found
    out it was too late.

    now i need to replace everything with new and wash very carefully the heads
    and block as i have oil in water... the typical caramel looking coolant..

    on top of that, my clutch finally died at the very same time... no getting into
    gear with the car standing still... only starting it up already in gear.

    everything but the aluminium pipes under the car will be replaced.

    i've been colecting all necessary parts ever since... necessary to do a major
    ... MAJOR... engine refresh... basically everything gasket/seal/washer.

    Have everything here, just need to send an original spare clutch i have to
    the clutch rebuilders, so they do their CF marvell.

    let's see if i have the nsx back on the road until the end of this year

    Thanks,
    Nuno

  4. #4
    Join Date
    Dec 2007
    Location
    Switzerland
    Posts
    1,006

    Default

    Sorry to hear your horror story.

    Did your car had the 'wrong' coolant in the system?

  5. #5

    Default

    Hi,

    first of all, this is much better, because it was a full blown thread hijack
    (sorry for that @britlude)

    Thomas, i always used coolant fully compatible with aluminium, but to chase
    all the leaks, one after the other, i didn't use OEM Honda...is way too expensive.

    it will be awhile, but the next update will be with the clutch rebuild... it's not
    directly Head Gasket Failure related, but it will go in under the same MAJOR
    job.

    Thanks,
    Nuno

  6. #6
    Join Date
    Dec 2007
    Location
    Switzerland
    Posts
    1,006

    Default

    Did you ever change all the hoses in the past?

  7. #7

    Default

    Hi,

    yeap... every one of them, back arround 2010

    back then, the big hoses under the car had leaks through the ropes
    inside the rubber.

    I used a Venair set for the 6 big ones, and every other i used OEM.
    Also a new tank back then

    Thanks,
    Nuno

  8. #8
    Join Date
    Dec 2007
    Location
    Switzerland
    Posts
    1,006

    Default

    Just wondering why you still had leaks after the big replacement of all hoses? Ok, you wrote that your head gasket failure was mainly due a radiator failure. A part that seldomly fails in a Honda, well, let's say much less than in other makes.

    Your story reminds me a little bit of the A/C leaks story since I have the car.

    I've heard of one that had a leaking system due to the wrong coolant used where the aluminium lines were attacked badly.

  9. #9

    Default

    As a retired radiator engineer can I add my two penny worth? Sounds to me that you first had a head gasket leak between the combustion chamber and the coolant. This would lead to over pressure in the coolant circuit,contamination of the coolant by corrosive combustion gases leading to hose and radiator failure.The value of using the correct coolant is the inhibitors which protect against corrosion.These are gradually depleted and the coolant needs to be replaced.
    "radiator broke on bottom fins" sounds like over pressure to me.

  10. #10

    Default

    Hi,

    Thomas and pralognan, the sequence of failures was:

    1 - Coolant level was dropping in the tank, slowly but steady.

    2 - At first glance, i didn't see any leaks in any part of the circuit

    3 - after a short while, i was able to get the car on a lift and remove the black plastic covering the hoses
    under the car. Found coolant green residues on the upside of that cover and saw that it was getting out by
    the ropes on both edges of both big hoses under the car.

    4 - Replaced all hoses, 6 Big ones with Venair, the rest OEM Honda and a new OEM tank

    5 - Coolant level kept going down, slower, but surely.

    6 - Discovered leaks on one of the big aluminium pipes that go from under the car and over the fuel tank.
    Replaced with a pressure tested used one.

    7 - Coolant level stabilized and slowly got down again. This time was one of the big alumium pipes that go
    from under the car to the front, the driver side thicker one. Again, replaced with a pressure tested used one.

    8 - Coolant level was stable for some time, like 3 or 4 months, and then it start to go down faster than ever
    before. This was when my OEM radiator failed... it was leaking bad...


    as i needed to daily drive the car, i checked the tank level right before every time i started the car... i never
    let the tank get empty, and always had an eye on the temp needle.

    If it started to go up, a quick blip on the throtle and it came immediatly down, which only happened when
    stopped at a light and such.

    In one of the drives, for the first time i found myself in a stop and go traffic and to avoid being hit by an
    asshole on a bike, i didn't look to the temp for like 2 or 3 minutes, and when i looked, it was up there in the
    red, with a blip, it came immediatly back down one trace below the middle. This was what killed my head
    gasket.

    Up to this point, the coolant was always clean just like the one in the jug, but after this, the coolant color
    got darker and some time later it suddenly became brownish, this was when the oil started to get in the
    coolant and right when i stopped the car for good.

    So, pralognan, i don't think that the first thing was the head gasket failure, just because of this:
    (but i can well be dead wrong)

    Prior to that red temp event, the compression test was always 200-210 in all 6 cylinders.

    Right after that high temp event, i made another test within a couple of days after and 5 cylinders were
    still at 200-210 and one on the front bank was just going up to 185.
    And it took more time for this to get to 185 than the others to 200-210.

    additional things i checked:

    - no coolant in the oil. Oil is still crystal clean today. Dark brown color as i use Sikolene Titan Race Pro S.
    - no significative oil level drop. As always, from 3/4 down to 1/4 in each oil change, i.e. each 7500kms.

    I discussed both with Kaz and with Larry B if i should change bearings and piston rings in this major refresh.

    Things in favour of NOT to do it:
    - The oil consumption doesn't justify it.
    - The compression tests show good compression.
    - My worries on mistakes torquing back the crank and rod screws/bolts and everything then go KABOOOM !

    So, with the above, they both said that it wasn't necessary as the block is apparentely with good health.
    BTW, it now has 220.000kms

    Man... i think i never wrote a post this long.. loool

    Thanks,
    Nuno

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