98 Toyota Camry Overheating

I have a 98 Toyota Camry that's temperature gage says it's
overheating. When I put the heater on the temperature stays the
same. When I put the air conditioning on the temperature gage goes
back down. It doesn't overheat every time I drive it but does most of
the time. I have never fully overheated the temperature gage will
just get really high and I have to turn the AC on or stop driving for
a few minutes. I have replaced the thermostat, radiator, water pump,
and temperature sensor. Could it possibly be something to do with the
fans that are mounted on the radiator? These were not replaced I took
them off of the old radiator and installed them on the new one. It
appears that the fans are not running when the car is running but when
I turn on the AC they start up. Is it possible that it is something
with the fans? Any help would be much appreciated.

Thanks,
Brant

On Tue, 7 Apr 2009 22:02:21 -0700 (PDT), bsmith95610
> wrote:

>I have a 98 Toyota Camry that's temperature gage says it's
>overheating. When I put the heater on the temperature stays the
>same. When I put the air conditioning on the temperature gage goes
>back down. It doesn't overheat every time I drive it but does most of
>the time. I have never fully overheated the temperature gage will
>just get really high and I have to turn the AC on or stop driving for
>a few minutes. I have replaced the thermostat, radiator, water pump,
>and temperature sensor. Could it possibly be something to do with the
>fans that are mounted on the radiator? These were not replaced I took
>them off of the old radiator and installed them on the new one. It
>appears that the fans are not running when the car is running but when
>I turn on the AC they start up. Is it possible that it is something
>with the fans? Any help would be much appreciated.
>
>Thanks,
>Brant

Are you sure it's overheating? Assuming it is, the most likely cause
is that the temperature sensor that is supposed to turn on the fans is
not working properly. Turning on the AC overrides that temp sensor
and makes the fans run which cools down the engine.

On Apr 9, 1:19*am, Ashton Crusher > wrote:
> On Tue, 7 Apr 2009 22:02:21 -0700 (PDT), bsmith95610
>
>
>
>
>
> > wrote:
> >I have a 98 Toyota Camry that's temperature gage says it's
> >overheating. *When I put the heater on the temperature stays the
> >same. *When I put the air conditioning on the temperature gage goes
> >back down. *It doesn't overheat every time I drive it but does most of
> >the time. *I have never fully overheated the temperature gage will
> >just get really high and I have to turn the AC on or stop driving for
> >a few minutes. *I have replaced the thermostat, radiator, water pump,
> >and temperature sensor. *Could it possibly be something to do with the
> >fans that are mounted on the radiator? *These were not replaced I took
> >them off of the old radiator and installed them on the new one. *It
> >appears that the fans are not running when the car is running but when
> >I turn on the AC they start up. *Is it possible that it is something
> >with the fans? *Any help would be much appreciated.
>
> >Thanks,
> >Brant
>
> Are you sure it's overheating? *Assuming it is, the most likely cause
> is that the temperature sensor that is supposed to turn on the fans is
> not working properly. *Turning on the AC overrides that temp sensor
> and makes the fans run which cools down the engine.

What he said. there is probably a relay that turns on the fans, that
would be the first place I would check. Next is whatever thermoswitch
in the radiator controls it. If you're real unlucky the fan relay is
not hard wired to a thermoswitch but to the PCM.

nate

bsmith95610 wrote:
> Could it possibly be something to do with the
> fans that are mounted on the radiator?

That's my guess. It sounds like the engine management system isn't
turning the fans on when the engine gets hot, but since they come on
with the AC, that cools things down.