Temperature guage question

[Gary G.]

I have a 75 coupe. Recently, the temp guage rises to the first mark between zero and 200. The car used to have the guage near the middle, or 200. The car runs ok, but the reading bothers me. I have searched the archives, and know that the guages are not that accurate. Do I have a malfunctioning guage, t stat, sender? Everything on the car is original, except the stat, which is a 195.

Any help would be appreciated.

[Tom H.]

Re: Temperature guage question

Hi Gary !

Looks like you live in CT. Are your readings you are getting for right now? Winter time vs. summer higher readings. I would say with cold outside conditions, you are probably reading about right.

[Gary G.]

Re: Temperature guage question

Yes Tom, the readings are today and a day that was about 16 degrees. Today it is about 45. I have fresh 50/50 antifreeze in the car, it runs fine. Maybe I will wait for a 90 degree day to see what it reads. I am also running 15/40 Rotella oil.

Perhaps everything is fine.

[Tom H.]

Re: Temperature guage question

She will get a bit hotter on a 90 degree day. Mother nature was helping out your cooling system today !!

[Joe L.]

Re: Temperature guage question

I have a 75 coupe. Recently, the temp guage rises to the first mark between zero and 200. The car used to have the guage near the middle, or 200. The car runs ok, but the reading bothers me. I have searched the archives, and know that the guages are not that accurate. Do I have a malfunctioning guage, t stat, sender? Everything on the car is original, except the stat, which is a 195.

Any help would be appreciated.

Gary------


First of all, a 195 degree thermostat is the correct thermostat for your application. You could use a 180, but that's not what was originally installed and it won't do much to reduce engine operating temperature, anyway, if there really is a cooling problem. A thermostat only controls the LOWEST temperature an engine will operate at after warm-up, NOT the highest.

I've never experienced a problem in which a gauge or sender suddenly "went out of calibration". Usually, they just fail and don't work, at all. However, I suppose it's possible that such a thing could happen. You could confirm the readings in several ways. First, use an IR non-contact thermometer. Or, buy a test gauge with sender of the appropriate range and temporarily install it.