"jim beam" > wrote in message
t...
> Gary Kaucher wrote:
> > "jim beam" > wrote in message
> > t...
> >> Gary Kaucher wrote:
> >>> 1994 Honda Accord EX, 4 door
> >>> 4 cylinder, Automatic Transmission
> >>>
> >>> I just recently replaced the Radiator fan motor, and now both my AC
fan
> >>> and Radiator fan seem to be capable of turning on and off. However,
> >>> I don't think that they are turning on soon enough. With the recent
hot
> >>> weather here in PA, if I idle the car with the AC off, I've noticed
that
> >>> the temperature gauge needle will rise to just under the red zone
(hot),
> >>> and then both fans (AC and Radiator) will come on, cool things a
> >>> little, turn off and then cycle on and off as they should, but at a
> >>> generally
> >>> higher temperature than I remember in the past. The radiator cap is
> > rated at
> >>> 13 psi. Is this the correct rating for the above vehicle? I am
wondering
> > if
> >>> it
> >>> may have been accidentally replaced last summer.
> >>>
> >>> Thanks,
> >>>
> >>> Gary
> >>>
> >>>
> >> before worrying about the cap pressure, consider the following:
> >>
> >> when was the thermostat last replaced?
> >>
> >> in what condition is the radiator? is it clogged/sludged? filled with
> >> bugs?
> >>
> >> what level is the coolant? are you losing any? any bubbles in it?
> >> [check inside the radiator, not just look at the expansion bottle.]
> >
> >
> > The thermostat was replaced last summer. When I looked into the
> > radiator recently I did not see anything particulary unsightly, but I
> > suspect that it may have been six years and 50K since the antifreeze
> > has been changed.
>
> hard to change the thermostat without changing the coolant.
>
> > I keep the coolant level between Cold and Hot, and
> > I don't appear to be losing any. I thought that I saw bubbles once in
the
> > expansion bottle, so I fiddled with the radiator cap, and they seemed
> > to go away.
>
> hmm, that's suspect.
>
> > I imagine that I could be due for some kind of radiator
> > flush and antifreeze replacement. The antifreeze doesn't look too bad,
> > but I suspect I've seen cleaner.
>
> can't hurt.
>
> >
> > I called an auto parts place just to see what pressure rating was listed
for
> > my Honda Accord's radiator cap and they said 16 psi. Since the one that
> > I have is 13 psi I wonder if it is the wrong radiator cap, and if it
would
> > make a
> > significant difference in the ECT sensor's ability to turn the fans on
at
> > the correct
> > temperature.
>
> no, it won't affect that at all. a higher pressure cap just elevates
> the boiling point a little.
>
> >
> > Or, is six year old antifreeze more likely to be a factor?
>
> not unless it's really dirty. check the thermal switch and the fan
> relays for operation. if the switch checks out ok, to eliminate the
> head gasket as a suspect, have a chemical test done on the coolant to
> see if there's exhaust gas in there. then look at the radiator again.
> they fill up with bugs and all kinds of other debris that impairs
> airflow significantly. if replacement is in order, i've had good
> experience with these folks:
>
>
http://catalog.eautopartscatalog.com...pe=A utomatic
>
> i'd go plastic tank.


This car is mostly driven on short trips over country roads. It is only
recently that we are
having really hot weather here in PA, so I suspect that this problem may
have existed
for awhile, possibly since last summer. Yesterday was particularly hot, and
I drove the
car for about an hour before I noticed that the fans were cycling at a
higher than
expected temperature (around the 3/4 mark). Overnight things cooled off, and
when
I checked the antifreeze reservoir, it looked like the radiator may have
sipped about
a pint out of it. I removed the radiator cap, started up the engine and
added antifreeze
whenever I could. I would say that it may have taken another pint . Now the
fans are back
to cycling on and off at about the 1/4 mark as Nick indicated. So I think
that might be back
in business. I did notice some things when I purged the radiator:

1) I would sometimes see bubbles coming from the coolant at the radiator
fill.
2) The level of coolant would go up and sometimes overflow
the radiator when I revved the engine up to about 2000 RPM.

Do either of these things imply a bad head gasket? If so, maybe that is the
reason that I needed to
add coolant. If not, maybe the radiator was never properly purged last
summer when the thermostat
was changed.

How can you tell when the thermostat opens? Does the big hose on top of the
radiator become
pressurized?

Thanks everyone for all the help.

Gary