Honda Car Forum

My 91 legend will overheat sometimes and if I turn the dial to hot or 90
degrees it will come back down. When I have it in the 60 degrees(cold)
mark it will jump to hot fast? Sounds like a thermostat I think? Do
you think this is right? Brand new radiator and new fluid within last
month. Headgasket is fine. Does a thermostat close when in cold and
open in hot postition?? Thanks!! Nelson

" " <porshapower@webtv.net> wrote in message
news:19767-3F5AB900-146@storefull-2278.public.lawson.webtv.net...
> My 91 legend will overheat sometimes and if I turn the dial to hot or 90
> degrees it will come back down. When I have it in the 60 degrees(cold)
> mark it will jump to hot fast? Sounds like a thermostat I think? Do
> you think this is right? Brand new radiator and new fluid within last
> month. Headgasket is fine. Does a thermostat close when in cold and
> open in hot postition?? Thanks!! Nelson
>

Overheating is such a common problem, yet pretty easy to pinpoint and
fix (in my opinion). First make sure your water pump is not leaking. Make
sure the two rubber hoses are still soft and plyable and are not cracked or
leaking. Flush out the radio and engine block with radiator cleaner (you've
eliminated this problem by replacing it). Make sure your fans are working
and kicking on. I had a car that everything worked perfect.....just the
radiator fan wasn't working so when I was idling, the car would
overheat...if im on the freeway....no problems. Then you wanna check your
thermostat. If thats ok, you need to make sure your water is actually still
working (is it pumping water?). Take off the top hose going into the top of
the radiator and take a garden hose and with the engine running...."flush"
the coolant system. Try reving the engine while doing this and see if you
are getting water spraying out of the top hose (comming out of the engine
block/thermostat). Of course empty your antifreeze and fill with water for
this test. if that all checks out...sounds like you might have a damaged
head gasket or an internal leak maybe (if you are loosing your coolant). If
you flush your system and test like this though, you should flush your
system again with a mild coolant cleaner to make sure you get all the dirty
garden hose water out of there....you dont want mineral-rich water in your
cooling system :-)

But based on what you are saying...when you turn the heater on...the car
cools down. Sounds like it could be three things (since you've already
replaced your radiator). It could be your fans aren't working, your water
pump is pumping water through the system fast enough (messed up pump? can
test as I said above). Is could very well be a bad thermostat (I am thinking
this). The thermostats should open at a specified temperature. They stay
closed when cold to help the engine heat up faster in the mornings. One the
water in the engine reaches a certain temp (175 F, 180 F...etc) it opens and
allows for the water to flow and cool the engine.

Take out your thermostat and see if it looks damaged. if it looks ok,
stick it into a pot of boiling water. Pop a thermometer into the water
(cooking thermometer or anything) to see the water temperature and see if
the thermostat opens. if the water is rapidly boiling (water temp above 200
degrees F or so) and the thermostat hasn't opened.....thats your problem.

Let us know how it goes.

Gabe

Air in the system?

<porshapower@webtv.net> wrote in message
news:19767-3F5AB900-146@storefull-2278.public.lawson.webtv.net...
> My 91 legend will overheat sometimes and if I turn the dial to hot or 90
> degrees it will come back down. When I have it in the 60 degrees(cold)
> mark it will jump to hot fast? Sounds like a thermostat I think? Do
> you think this is right? Brand new radiator and new fluid within last
> month. Headgasket is fine. Does a thermostat close when in cold and
> open in hot postition?? Thanks!! Nelson
>

I am going to try all this during this week!! Thanks VERY MUCH for your
help!! Nelson

wrote:

> I am going to try all this during this week!! Thanks VERY MUCH for your
> help!! Nelson
>

Gabriel is to be commended, it was an extensive and thorough post

"Franz Bestuchev" <fbestuchev@n05p4m.userealsugar.com> wrote in message
news:bjjjbb$me0$1@peabody.colorado.edu...
> wrote:
>
> > I am going to try all this during this week!! Thanks VERY MUCH for your
> > help!! Nelson
> >
>
> Gabriel is to be commended, it was an extensive and thorough post
>


:-)

Just helping out...Let us know how it goes

:-)

So far so good. Flushed the system and am running a cleaner. Have
driven all day and no overheating. Either there was something clogged
or ?? I will let you know as the next day comes along. Thanks to
Gabriel and everyone else who helped!! Nelson