My 289 seems to run warm at highway speeds (65mph or so). It runs about 210-215 but settles down to 190 around town. I thought the lower hose was collapsing but I put a spring in it and didnt help. This is a mildly built 289, headers, new 3 row radiator, Taurus fan w/210 on 190 off t-switch. The fan stays on the entire time I'm on the fwy, but when I get off the fwy it cycles on and off normally. The mechanical guage seems to read with the t-switch plus I checked it with boiling water before installing so I believe it's accurate. Head gaskets were installed correctly. Only other thing is a trans cooler installed in front of the radiator. Shouldnt it be running cooler on the fwy? Thanks in advance.
Runnin warm
- Thread starter 6t7coop
- Start date
since the temps drop back down, i doubt there is an issue. likely what is happening is the thermostat isnt opening quite fully, and when you hit the freeway the temp climbs a bit until airflow brings the temps back down. personally i wouldnt worry unless the temps get above 215 and stay there.
12sec67
Active Member
Possibilities:
- as air flow increases due to speed, through the radiator, fans can actually inhibit optimized air flow. (@ 60 MPH the fan is useless considering a 60 mile an hour head wind)
- If you are running overdrive on the pulley and/OR have a high flow WP, you may not be spending enough time in the radiator.
- I do not run an AOD so pardon the ignorance, is it possible trans temp is contributing differently @ speeds. (I would think not but if the AOD put you close or below your stall RPM...)
- I run only ~ 25% anti-freeze, distilled water, and wetter. Antifreeze raises the boiling point but also decreases heat xsfer properties.
- How's your timing are you getting the advance you need at the higher RPMs?
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- as air flow increases due to speed, through the radiator, fans can actually inhibit optimized air flow. (@ 60 MPH the fan is useless considering a 60 mile an hour head wind)
- If you are running overdrive on the pulley and/OR have a high flow WP, you may not be spending enough time in the radiator.
- I do not run an AOD so pardon the ignorance, is it possible trans temp is contributing differently @ speeds. (I would think not but if the AOD put you close or below your stall RPM...)
- I run only ~ 25% anti-freeze, distilled water, and wetter. Antifreeze raises the boiling point but also decreases heat xsfer properties.
- How's your timing are you getting the advance you need at the higher RPMs?
-
The radiator was new when I first fired up the rebuilt 289. I'm pretty sure all air is out, I let it run w/o rad cap until fully warm and the some. How do you really know if there is an air pocket or not? blandq, the trans is a c4 and someone else also suggested that maybe the coolant is flowing too fast at speed. Although the water pump and pulley are stock. How would one slow the coolant down, is there a restrictor that can be put in the system somewhere. Would a 195 t-stat help?
I hope you are running a shroud, other wise the air is going everywhere but where it needs to. Yes, it should run cooler at highway speeds, much cooler. I threw a belt and was hitting 230 degrees, but once I got up to speed (65 mph), and threw it in neutral, the temp dropped to 195 with no water pump at all! Of course, as soon as I put it in gear to climb a hill, the temp climbed, but a shroud makes a huge difference. Also, the hood seal above the radiator helps air actually flow thru the rad. and not around.
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