Honda thermostat fixed + how to test your thermostat...

Discussion in 'General Motoring' started by corrymartin, Mar 17, 2009.

  1. corrymartin

    corrymartin Guest

    See my original message below:

    So after taking the car into the dealer for a total of seven times (3
    of which were to have them flush the radiator because they couldn't
    seem to remember to fill the reservoir tank...), I finally got fed up
    with the lack of service from my dealer and called Honda Canada.

    After explaining the problem, they called the dealer on my behalf.
    The dealer ordered a new thermostat, and installed it when it
    arrived. My car heats up fine now. Even at -30. The service manager
    said it must have been 'selectively sticking'. (Probably just when
    the engine was running).

    FYI: From what I can tell, there is only one temperature of
    thermostat available for the 06+ generation civic at this point, (set
    at 170 degrees) I've called jobber shops and most don't even stock the
    part because its a new style. (They usually start making parts once
    the warranties are up). Canadian tire carries the right thermostat.
    If you get a chance to order a hotter thermostat (190 degrees), they
    work great- very nice investment for the wintertime. You will however
    notice a small drop in fuel economy and performance.

    My advice:

    If your car reaches normal temperature and then the temperature drops
    during long downhills or when your heater is on full- then your
    thermostat is shot. My test was the 'two mile hill' test. Once the
    engine is at full temperature, drop the car in neutral at the top of a
    large hill (keep the load on the engine minimal), turn the heater on
    full and watch the temperature gauge. You shouldn't notice the
    temperature drop. The thermostat is there to keep your engine at
    proper temperature- that's it's only purpose. Once the coolant
    temperature starts dropping, the thermostat closes to keep the engine
    at proper temp. If your temperature drops, then the thermostat is
    stuck open.

    The only way to know for sure what is going on is to remove the
    thermostat. The factory service manual describes removing the
    thermostat, place it in a pot of water with a thermometer, and heat it
    up. (suspend the thermostat/thermometer off the bottom of the pot).
    The thermostat should be closed initially, and start opening at about
    155 or 160, fully open at 170 and visa-versa.

    Part of my frustration was because every time I brought the car in,
    I'd ask what they did. They refused to pull the thermostat just to
    test it- even though it says to do so in the dealers' service manual.
    If they aren't doing that- what are they doing?

    If your dealer isn't honoring your warranty, call Honda Canada. It
    worked for me. Other than that, I've resolved to sell my car. I've
    owned honda's all my life and they've been great- but right now I'm
    worried that if something serious happens, I'll be left in the cold
    (... yeah I know). At least I won't be buying a new car without a


    (OLD Message Below)

    Forgot to mention that I drive an 07 Civic. This is its first cold
    winter, so I'm only noticing the problem now.

    corrymartin, Mar 17, 2009
  2. corrymartin

    jim beam Guest

    saving themselves money and trying to run the clock down on you. they
    don't get paid as much for warranty repair as they do for stuff out of

    not sure i follow the logic of that. you've just cracked the code for
    getting stuff done, but now you're walking away.
    jim beam, Mar 17, 2009
  3. corrymartin

    Tegger Guest

    wrote in

    Like I've said all along: There's surely a TSB coming soon.

    No Honda has an "optional" OEM thermostat. The cooling system works just
    fine with the single one that's specified.

    That's interesting. I wonder what's the difference between old and new?

    Bad idea. Never install a hotter thermostat than what was specified for
    your car.

    Your car is meant to take a thermostat that says "78C" on it, which
    translates to 170F. That's the temperature at which it starts to open. A
    170 is fully open at 90C, or 194F.

    A thermostat that says 90C or 194F on it will be fully open at about
    215. WAY too hot.
    Tegger, Mar 17, 2009
  4. corrymartin

    M.A. Stewart Guest

    From the 1986 Canadian Honda Accord Shop Manual (First Edition 9/85)
    Honda No.'s 62SE300C and (SM)C3408706G

    Page 10-7

    Lift height: 8 mm (0.31 in.)
    Starts opening: Primary: 82 Deg. C plus or minus 2 (180F + or - 3)
    Secondary: 85 C + or- 2 (185F + or - 3)
    Fully open: 95 C (203F)

    Lift height: 8 mm (0.32 in.)
    Starts opening: 86--90 Deg C (187--194F)
    Fully open: 100 C (212F)

    Happy St. Paddy's (Mar.17)
    M.A. Stewart, Mar 17, 2009
  5. corrymartin

    Tegger Guest

    (M.A. Stewart) wrote in

    Well, if you want to go THAT far back...

    Let me a bit more precise, then: No Honda made _after 1989_ had an
    "optional" thermostat.

    None of my numerous Honda shop manuals list any optional thermostat. Except
    the one for the '86-'89 Accord.

    Certainly, however, the OP's '07 Civic takes only one specified thermostat
    rating, so your point is moot.

    I'd be happier if St. Paddy's was on the weekend. It's tough getting
    hammered when you have to go to work the next day.
    Tegger, Mar 17, 2009
  6. corrymartin

    jim beam Guest

    that's a carburetted vehicle though. fuel injection vehicles are very
    particular on coolant temperature being correctly maintained. that's
    why defects like sensor drift or thermostat drift have such significant
    jim beam, Mar 18, 2009
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