1975 Stingray running hot
Thread Starter
Cruising
Joined: Sep 2009
Posts: 14
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From: Wadsworth Ohio
1975 Stingray running hot
I have replaced the radiator, water pump and thermostat. When I am on the highway in fourth gear, the car run's hot. When I downshift, the temperature drops a little. I still think it is running way too hot at 220 degrees. Any suggestions? Thanks
Racer
Joined: Jan 2009
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From: Near Round Top (pop. 90) Texas
Race Director
Joined: May 2007
Posts: 11,334
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From: Out of Site...Out of Mind. Corvette: anything else is just transportation.
St. Jude Donor '09 thru '20
My '75's been running around 200 lately. Usually stays around 180. Have had some carb issues that has made me have to throttle the gas pedal in order for it to stay running at a stop. Have the carb dialed in to where it idles smoother and at a proper RPM. Now all I have to do is wait for the skies to clear.
Racer
Joined: Jan 2009
Posts: 482
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From: Near Round Top (pop. 90) Texas
I was thinking a 160 degree thermostat.
My '75's been running around 200 lately. Usually stays around 180. Have had some carb issues that has made me have to throttle the gas pedal in order for it to stay running at a stop. Have the carb dialed in to where it idles smoother and at a proper RPM. Now all I have to do is wait for the skies to clear.
My '75's been running around 200 lately. Usually stays around 180. Have had some carb issues that has made me have to throttle the gas pedal in order for it to stay running at a stop. Have the carb dialed in to where it idles smoother and at a proper RPM. Now all I have to do is wait for the skies to clear.
Also if you run with a 160 thermostat, you run the risk of it staying open continuously, actually causing your car to overheat.
In extreem conditions all the water in a factory rad system can get too hot.
A 185 thermostat running at 200 degrees is actually close to ideal.
If you have a 160 degree thermostat and you are running 200 degrees ya might want to look for the real problem and change back to a 180.
JMHO
Instructor
Joined: Sep 2008
Posts: 143
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From: San Francisco CA
Exactly the question i wanted to ask about my 75 running hot also.
I have on order a 180degree thermo to be installed, and also have a new aluminum 3 row radiator to be isntalled as well with dual electric fans.
The car is missing the radiator fan shrouds since the stock fan is removed, but I will fabricate something for it hear the top.
As for the bottom, toolman1981, you mentioned front under spoilers? So should I not make the lower shroud piece and instead make a sort of "scoop" similar to the C5 radiator lower air scoop spoiler?
This overheating is pretty much the only thing keeping me from driving the car. =/
PS my water pump is new from what the previous owner had said when motor was rebuilt. Other than that, I am guessing I have the same problem as jskenter
I have on order a 180degree thermo to be installed, and also have a new aluminum 3 row radiator to be isntalled as well with dual electric fans.
The car is missing the radiator fan shrouds since the stock fan is removed, but I will fabricate something for it hear the top.
As for the bottom, toolman1981, you mentioned front under spoilers? So should I not make the lower shroud piece and instead make a sort of "scoop" similar to the C5 radiator lower air scoop spoiler?
This overheating is pretty much the only thing keeping me from driving the car. =/
PS my water pump is new from what the previous owner had said when motor was rebuilt. Other than that, I am guessing I have the same problem as jskenter
Administrator
Joined: Jul 2000
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From: About 1100 miles from where I call home.
A couple other thoughts:
-The temp sending units are notorious for incorrect readings. Can you verify that the temp readings are correct?
-Check the timing.
-The temp sending units are notorious for incorrect readings. Can you verify that the temp readings are correct?
-Check the timing.
Race Director
Joined: May 2007
Posts: 11,334
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From: Out of Site...Out of Mind. Corvette: anything else is just transportation.
St. Jude Donor '09 thru '20
Be careful not to run it too cool, vac switches still need temp to properly function.
Also if you run with a 160 thermostat, you run the risk of it staying open continuously, actually causing your car to overheat.
In extreem conditions all the water in a factory rad system can get too hot.
A 185 thermostat running at 200 degrees is actually close to ideal.
If you have a 160 degree thermostat and you are running 200 degrees ya might want to look for the real problem and change back to a 180.
JMHO
Also if you run with a 160 thermostat, you run the risk of it staying open continuously, actually causing your car to overheat.
In extreem conditions all the water in a factory rad system can get too hot.
A 185 thermostat running at 200 degrees is actually close to ideal.
If you have a 160 degree thermostat and you are running 200 degrees ya might want to look for the real problem and change back to a 180.
JMHO
I got my '75 out today. Still hitting 200-205. Beginning to think the thermostat might be trying to stick.
Might try another 180 thermostat and see what happens.
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Race Director
Joined: May 2007
Posts: 11,334
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From: Out of Site...Out of Mind. Corvette: anything else is just transportation.
St. Jude Donor '09 thru '20
Got the new 180 thermostat in today. Unfortunantly, rain moved in so I will have to do a shake down run another day.
OP. How's your '75 doing?
OP. How's your '75 doing?
Race Director
Joined: Jun 2000
Posts: 10,046
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From: FL
Make sure you have the spoiler and the radiator seals. Without both, you will not airflow through the radiator.
Seals ($25):
http://www.ecklers.com/product.asp?p...5&dept_id=1256
Spoiler ($40):
http://www.ecklers.com/product.asp?p...3&dept_id=1435
Seals ($25):
http://www.ecklers.com/product.asp?p...5&dept_id=1256
Spoiler ($40):
http://www.ecklers.com/product.asp?p...3&dept_id=1435
