Overheating 91 Accord LX

Discussion in 'Accord' started by dannd, Mar 3, 2007.

  1. dannd

    dannd Guest

    Hi,

    I have an overheating condition with my Accord that I've been working
    with for about a month now.

    So far my parts list consists of:
    1)Thermostat and hoses
    2)Radiator
    3)Temperature switch A ( Water outlet housing )
    4)Gauge temperature sender
    5)Timing belt and water pump (1 year ago as of Feb 22 from the
    dealership)

    Around town car is fine (temp gauge reads around halfway mark),
    Thermostat opens as I can feel the top hose is hot. On highway gauge
    climbs to around the 3/4 mark about 1/4 away from hot. Turn heater on
    to bleed off excess heat and everything settles down until temp goes
    back up.
    I have done a meat thermometer test with the cap off, and the temp
    goes up to 195 and levels off, with the gauge showing about halfway. I
    turned the A/C on and the fans do not automatically turn on, they wait
    about a minute or two before coming on. After parking the car and
    turning it off, the fan comes on about 3 minutes after the car is
    parked at normal operating temperature. I am not losing any coolant,
    and nothing is mixing with the oil. I don't have any smoke other than
    normal cold morning exhaust. I'm going to have the compression checked
    just in case, but this really doesn't seem to be a head gasket or head
    issue.

    Anybody have any ideas?
     
    dannd, Mar 3, 2007
    #1
  2. dannd

    jim beam Guest

    look for bubbles in the expansion bottle. if you have any, it's
    definitely head gasket. you'll see them at idle when the motor is at
    full working temperature. traditional symptoms of water in the oil are
    rare in hondas because of the wet cylinder liner configuration - any gas
    leaking from the cylinders can only go into the coolant unless the head
    is cracked.

    regarding repair, are you planning on doing the work yourself? if so,
    the math works, but if you're having it done by a shop, examine the
    economics of simply replacing the engine with a used low mileage
    japanese import engine. head gasket repair takes hours and is very
    labor intensive. shops also routinely skim heads, which i personally
    don't approve of unless there's a definite head warping problem.
     
    jim beam, Mar 3, 2007
    #2
  3. dannd

    Tegger Guest

    wrote in 30g2000cwc.googlegroups.com:


    If the car begins to overheat when the engine is operating at elevated
    speeds, there is a problem with heat being shed.

    What coolant are you using? I wonder if your block and/or rad is silted up
    and not allowing sufficient fluid flow.

    How old is the radiator, and what brand is it? If you have an automatic, is
    the rad a dual-core or single-core?
     
    Tegger, Mar 3, 2007
    #3
  4. dannd

    dannd Guest

    It's a brand new radiator from Advance, the motor is low mileage by
    Honda standards (85,000). Since the fans don't come on with the A/C
    I'm leaning towards it being either :
    A) The fan timer ( I think I've found where it is in the car , but I'm
    not sure exactly)
    B)A wiring problem between the switch and the fan motor.
    C)Fan motor

    But since neither of the fans are coming on with the A/C it's
    screaming to me that it's the timer.

    P.S.: I swapped the power window relay with the Fan relay on the under-
    hood fuse box, and no change.
     
    dannd, Mar 3, 2007
    #4
  5. dannd

    jim beam Guest

    you're barking up the wrong tree dude. if the car overheats when you're
    on the freeway, it's /not/ the fans. freeway airflow vastly exceeds
    fan-induced airflow. especially this time of year.

    check for gotchas like newspaper stuck to the a/c condenser, but mainly,
    look into the head gasket. you only need to over-heat the motor once
    [say a crack in the old radiator] and differential thermal expansion can
    break the seal. from that point on, it's going to leak slowly, which
    you won't notice, then faster, until you do notice. overheating at
    freeway speed is one of those symptoms.
     
    jim beam, Mar 3, 2007
    #5
  6. dannd

    dannd Guest

    Yeah, but still the fans not coming on with the A/C is another symptom
    towards it being a switch or relay.
     
    dannd, Mar 3, 2007
    #6
  7. dannd

    motsco_ Guest

    ----------------------------------

    Are you keeping the reservoir filled to the -MAX- mark (per the manual)?
    It's one of the best ways to really figure out what's happening. If you
    don't keep enough coolant in the reservoir the temp sensors can end up
    high-n-dry when the thermostat opens and then the fan won't run when you
    come off the highway.

    It's also a good way to tell if you're USING coolant, either to displace
    air or through leakage. That's why the manual tells you to make sure to
    fill the reservoir any time you change the coolant or have work
    performed on the system. It just makes sense to keep some reserve in the
    reservoir.

    My coolant stays at max summer and winter, by itself. It's a 'peace of
    mind' kind of thing.

    'Curly'
     
    motsco_, Mar 3, 2007
    #7
  8. dannd

    dannd Guest

    It is right smack dab between the Min and Max mark, it never runs any
    lower, or higher.
    I also ran it up to temp and turned the A/C on a little while ago and
    let it run for about 10 minutes. The temp never went up past half on
    the gauge (should be around 195 degrees). And neither of the fans came
    on. I unplugged the A switch (the one that controls the radiator fan)
    and checked it for continuity with my volt meter it showed a constant
    flow across the terminals of around 11.5 volts. Noting that the upper
    hose is hot, and the bottom hose is pressurized, this tells me that
    the water pump is flowing correctly, the thermostat is open, and the
    switch on the outlet housing has continuity. It's looking more and
    more like the timer is bad.
     
    dannd, Mar 3, 2007
    #8
  9. dannd

    Tegger Guest

    wrote in


    This is NOT your problem. Fans are there to force airflow through the heat
    exchangers at IDLE. At speed they are neither used nor needed.

    You have a problem with fluid flow through the cores or through the block.
    You should also verify the actual temperature with an infrared thermometer,
    just to be certain it isn't the gauge misleading you.

    Did you use an OEM thermostat? Just because the upper hose gets hot doesn't
    mean the thermostat has opened, or has opened enough.

    When the car is beginning to overheat, feel the rad all over with your
    hand. Is it equally hot all over, or are there cooler spots?
     
    Tegger, Mar 3, 2007
    #9
  10. dannd

    dannd Guest

    Another one I just tried was jumpering the connections across the
    harness that plugs into A switch. by theory, and advice, this should
    have made the fan come on. The fan did not start. I then used my handy
    old volt meter to check and I was getting 13.5 VDC across the harness
    which tells me the circuit is powered up. The relay is good, as I
    checked it by swapping it with the power window relay right next to it
    and the power windows still work. It's either got to be the timer, the
    motor, or the wiring.
     
    dannd, Mar 3, 2007
    #10
  11. dannd

    Tegger Guest

    wrote in @z35g2000cwz.googlegroups.com:


    This does not tell you the thermostat is open, or is/isn't open all the
    way.
     
    Tegger, Mar 3, 2007
    #11
  12. dannd

    dannd Guest

    Tegger, I used a Stant thermostat from Advance and installed it at the
    same time as the radiator about 3 weeks ago.
    The dealership said I was getting proper coolant flow through the
    block as they checked out the water pump under warranty. The reason I
    am suspicious about the radiator fans not coming on when the A/C is
    engaged is I have been told by several people that the fans should
    come on with the A/C.
     
    dannd, Mar 3, 2007
    #12
  13. dannd

    jim beam Guest

    ok, now we're getting there. use a honda thermostat. yes, the
    aftermarket "should" be ok, but it isn't. make sure it's fitted
    correctly too. right way up, right way out. forget the fans in your
    diagnostics. you'll need to fix them, but they're not the cause of the
    overheating.
     
    jim beam, Mar 3, 2007
    #13

  14. How old is the radiator? You are stating the classic conditions for a
    plugged up unit...

    JT
     
    Grumpy AuContraire, Mar 3, 2007
    #14
  15. dannd

    Tegger Guest

    wrote in



    There ya go. Rip that sucker out and put in a proper dealer thermostat.

    Bet your problem goes away.
     
    Tegger, Mar 3, 2007
    #15
  16. dannd

    dannd Guest

    Turns out it was a brand new junk thermostat from Advance auto parts.
    Installed correctly and everything. We used a buddy of mine's IR temp
    gauge and noticed that the temp was 195 on the engine side of the
    thermostat, and 120 on the hose side. BINGO!!! no coolant flow.
    Thanks for the input.
     
    dannd, Mar 4, 2007
    #16
  17. dannd

    Tegger Guest

    wrote in @c51g2000cwc.googlegroups.com:



    Ah, the joys of aftermarket parts!

    Hope you learned a lesson here.
     
    Tegger, Mar 4, 2007
    #17
  18. Though I have not had any overheating problems, I am going to get a
    couple of OEM thermostats for the next incursion into the cooling
    system. I'm convinced!

    JT
     
    Grumpy AuContraire, Mar 4, 2007
    #18
  19. I learned my lesson with my old Volvos, the first cars I had in a while that
    had temperature guages. Aftermarket thermostats, mostly Stants, were all
    over the place. Some were too hot, most too cold, and nearly all of them
    wandered up and down the temperature scale at will. The first time I used a
    genuine OEM thermostat it was like magic.

    Mike
     
    Michael Pardee, Mar 4, 2007
    #19
  20. dannd

    dgk Guest

    I don't get it. If it's so well known that aftermarket thermostats are
    crap (I had the same problem once, replaced the thermostat and the
    problem remained), isn't it time that they got sued? Car manufacturers
    with bad parts have to do recalls.
     
    dgk, Mar 6, 2007
    #20
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