Author Topic: temp guage  (Read 1701 times)


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temp guage
« on: January 04, 2011, 11:15:05 PM »
The temp gauge on my 69 L78 never moves above the 2nd line above "cold", even after driving for half an hour. 
Is that normal, or is it a bad gauge?


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Re: temp guage
« Reply #1 on: January 05, 2011, 01:29:13 AM »
Tape some plastic as an "apron" over your radiator and go for a short drive. Watch the gauge as it should want to over-heat.

Maybe your cooling system has ample capacity.

You could try a warmer (perhaps 195F) thermostat if you think it's running too cold. Maybe it has a 160F or 180F in there now.
195F is the original factory temp according to the Service Manual.
Restoring my RHD 69 Jane in Melbourne, Australia.


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Re: temp guage
« Reply #2 on: January 05, 2011, 04:22:38 AM »
Sounds like a thermostat issue. It is not supposed to open until correct operating temp has been reached. This was a common solution for customers with heater problems. Pull the radiator cap, look inside with cold running motor. Solution should not be flowing much until it heats up.
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Re: temp guage
« Reply #3 on: January 05, 2011, 05:42:34 PM »
These gauges aren't laboratory-standard instruments - they give general indications. Shoot the upper radiator hose just above the thermostat housing after it warms up (thermostat open) with an I.R. gun to see the actual operating temperature.
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