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Re: '85 GT cooling probs

In a reply to my earlier question, Zafer Mehmood says:
>Considering that you have problems with the temp fluctuating, here are some
>obvious items to rule out (you may done this already):
>- Operation of the radiator cooling fan. This could be turning on/off at
>the wrong times or running at the wrong speed. This can easily create the
>symptoms you describe. The thermoswitch that determines the engine temp
>and turns the fan on/off could be flaky. I would suggest checking the Bentley
>manual for specifics.

I haven't really checked into this that much.  I've made sure that the radiator
fan is cycling on and off, but the temperature gauge doesn't drop any when it
is running.  I would almost say that the temp. gauge sender is faulty, except 
that the oil temperature increases significantly when the water temp. gauge
is up near H.

>- If this checks out ok, try replacing the thermostat.

I don't think this is the problem.  I pulled the thermostat totally and ran 
without it for a while, and the car exhibited the same symptoms.

>- You mentioned adding fresh coolant recently. Is the coolant concentration
>still within spec? High conc of coolant reduces its heat dissipation 
>The conc should be about 50% with protection down to -38 F.

I'm almost sure that the coolant is within spec.  When I said I added fresh 
coolant recently, I actually meant that I added fresh mix (50/50 ratio).

The only problem I can think of is some sort of blockage, but then I would 
think that it would just run very hot continuously, not fluctuate the way it
Could a dying water pump cause problems?  I've started to lose quite a bit
of coolant within the past 3 weeks, and I cannot find a leak in any hoses or
other obvious connections.  Also, the engine recently has begun making a
high-pitched whining noise, and I haven't had time to look into that.