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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: sbx22 on March 04, 2017, 11:29:08 pm

Title: Normal temperature gauge reading? SEE PIC INSIDE
Post by: sbx22 on March 04, 2017, 11:29:08 pm
This is my normal operating temperature. During a cold morning before starting, the gauge will read all the way to the left, cold. I've always wondered if this is normal, and is it reliable. For some background, I've replaced the temperature sensor on the engine block 3-4 years ago just to make sure things were working when I was doing an overhaul. Thanks for your input.

(http://i462.photobucket.com/albums/qq344/sbx22/0517151313_2.jpg) (http://s462.photobucket.com/user/sbx22/media/0517151313_2.jpg.html)
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: sbx22 on March 05, 2017, 07:32:16 am
Thermostat is 180 degree by the way
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: bedwards on March 05, 2017, 07:47:37 am
The gauges are notoriously inaccurate. Having said that yours looks very low. If you thermostat is stuck open, I would expect the temps to swing wildly with the outside temp, Its easy to tell. You can buy a cheap digital thermometer.
Be sure and get one that reads as high as you need to go. I have this one that does all I need #69465 Harbor Freight.
Get the truck to operating temp and check the temp on the output of the thermostat housing. It should be very near the 180. If not you need a thermostat.
This thermometer can help you figure which cylinder is not firing and many other temp related uses.
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: VileZambonie on March 05, 2017, 09:38:01 am
You should have a 195° thermostat to read normal
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: Engineer on March 06, 2017, 12:00:20 pm
That is where mine would read with the 180°F thermostat.

If you have a 195°F thermostat it will read approximately the same margin on the opposite side of that first white mark.
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: sbx22 on March 08, 2017, 09:08:24 pm
Thanks guys. I will swap to a 195 soon.
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: 75gmck25 on March 10, 2017, 11:34:46 am
I have a 195 degree thermostat, and have both the stock in-dash temp gauge and a separate mechanical temp gauge.  When the mechanical gauge reads about 195, the needle on the in-dash gauge is still only at the white line at quarter scale.   

I've always assumed it reads low due to aged wiring, or a gauge or temp sender that's a little off.

Bruce
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: Rapid Roy on May 04, 2017, 09:16:57 am
I have had strange temp gauge problems for about 2 months. Or at least thought it was gauge problem. Got new gauge, did same thing. Decided to replace sender, fixed problem even though replaced sender last November. Now hand shows from around 12:00 to 1:00 position depending if using AC or not. You may have a sender problem too, not sure. You can look for my recent post on this to get more info. I have the same gauge you have.
Title: Re: Normal temperature gauge reading? SEE PIC INSIDE
Post by: MrFiveOh on May 04, 2017, 09:59:59 am
I have a 195 degree thermostat, and have both the stock in-dash temp gauge and a separate mechanical temp gauge.  When the mechanical gauge reads about 195, the needle on the in-dash gauge is still only at the white line at quarter scale.   

I've always assumed it reads low due to aged wiring, or a gauge or temp sender that's a little off.

Bruce

Id check your coolant level, mine was acting like you describe and it was extremely low.