Hello,

I need some help I have an 83 TA with a 305 (Vin H), the temp gets almost into the red at hiway speeds above 65 and any where from 55-65 it runs around 220-250 deg but I can idle and cruse 30-50 all day long and it does not get above 220 on the guage on a 70 deg day, it has a clutch fan and the air dams are in place, in the winter it does not get above the 220 mark and the heat is hot.

and when it is running hot I can turn the heater on but that does not change the temp guage readings at all.

Please help I really do not want to blow the engine or head gaskets.

 

pull off your radiator hose and water neck and see if you have a thermostat in it. if not, when running at higher rpms, the water is running to quickly through the engine and radiator and not properly getting cooled down. you need a "restrictor" in there. either a thermostat, or just the housing with the guts pulled out.

 

sounds like the gauge could be reading higher than
actual temp-my '82 z28 with mostly stock cooling
system,including A/C in operation runs around 195 in
70*weather,but i can get it up to around 220-230 by
running it hard on the highway on a hot day-thirds,at
least the earlier ones,do not get the best ram airflow
through the radiator at high speeds-tested this once
by placing a spare electric fan in front of the radiator
and hooked the motor wires to a voltmeter so the volts
generated could be measured to recon the airflow.
on one very hot day tried a direct drive flex fan in
place of the stock clutch fan-fixed the high speed
heating problem and pulled a lot more air through the
radiator than the ram airflow was providing at 80 mph
-could notice the HP draw at over 4500 rpm though,so
stuck with the clutch fan.
For your car,an old dirty radiator might be the problem
as the aluminum core ones in particular seem to lose
effectiveness when they get just a little rust and scale
and the air dam might need improved as they can fold
back under at high speed if they have been damaged
over the years-mine does this,will make an improved
one later-it's low on the list right now

 

Thanks for the input but I found what I missed the first time the thermostat was stuck partally open and would not move either to close or open all the way.