Clem, Thanks for your response.
I realize that you can't wait for it to cool when it's red-lined. But if you
> turn the a/c on does the temp ever get out of hand?
Yes, if the car is running hot and I turn on the AC, which in turn switches on the fan, even then the temperature doesn't go down. It keeps rising.
Now... if the fan running still doesn't cool your engine, then I'd go with
> the thermostat change.
Is it normal for the car to overheat so bad that even the fan running cannot cool it. Could this signal a problem in addition to the bad sensor/thermostat ?
Thanks!!
> Thanks to all those replied. Based on the responses, can I assume that
> > for the symptoms that my car is showing, its not a radiator problem.
> > Can I rule out replacing a radiator or a radiator flush ? The problem
> > could be a bad fan relay, coolant temperature sensor, thermostat ?? >
>
> Sounds like you got it. :) It's interesting that when the fan IS running
> (With a/c on) it still does not cool the engine.
>
> I realize that you can't wait for it to cool when it's red-lined. But if you
> turn the a/c on does the temp ever get out of hand?
>
> I bet you have a bad coolant switch. You called it a sensor... which would
> have variable resistance output and is used to give the computer a reading,
> or the gauge a reading. The cooling switch (for the fan) is just that. It
> closes the switch to turn the fan on when it gets hot enough, and opens the
> switch when it's cool enough. If your engine is overheating and the fan is
> not running, something is wrong with this switch (since you've determined
> that the fan does actually work) or the associated wires.
>
> Now... if the fan running still doesn't cool your engine, then I'd go with
> the thermostat change.