Temp Gauge Behavior

[james accordino]

--- "Martin W. N. Suryadarma"
<msuryadarma at mail.wesleyan.edu> wrote:
> In the summer, my engine temp usually goes up to the
> middle line and the
> fan will kick in. It stays around the middle during
> city driving. If I go
> to highway, it can go down to the line before the
> middle one.

Normal, so far.

> have air conditioner running, the temp will never go
> as high as to the
> middle line. It seems that the air conditioner makes
> the engine run
> cooler, which doesn't make sense

You're right, that doesn't make sense.  The condenser
SHOULD be dumping heat right in front of the radiator,
raising it's temp.  That's what happens in every car
I've ever owned or driven with AC.
 
> Now in the winter, the same thing happens. During
> city driving it gets to
> the middle, then fan kicks in. Of course, I'm in
> Philly, so it's not that
> cold yet here. BUT I just noticed, if I have the
> heater on, the temp is
> really low, it's only around the 1/4 mark, and
> doesn't move up during the
> same driving condition. 

The heater core is acting like a secondary radiator,
dumping engine heat into the pass. compartment.  The
colder the pass. compartment, and the higher the fan
speed, the greater the drop on the temp. gauge.  This
is both normal and expected.

Jim Accordino