Team Camaro Tech banner
1 - 7 of 7 Posts

294 Posts
Discussion Starter · #1 ·
Just want to make sure my console temp gauge is working right.
There are no labels or numbers on this. Even after running the car for a half hour, the needle never gets too far past the first black line.

I guess I'm just used to the ones that have operating range about half way.

Is this normal?


16,053 Posts
Yep mine ran one 'tick' (small line) past the first larger black line (1/4 line) :)

Premium Member
616 Posts
Hi 68RS
I went thru some Cooling Issues with my 69 427 BB, lots of info out there and tried a bunch of stuff.

And I agree with you as to What do the Different Lines on the Console Gauge or Dash Gauge represent for Temperatures.

I read somewhere about the Yellow part of the Gauge being 212 Deg. and the Red being 230 Deg.

I had all my Gauges Cleaned and Recalibrated by Instrument Specialties in North Kingston, RI.
I can only assume my Gauge’s will give me the Proper readings, that being from where they get the Voltage or How much Resistance in the Circuit.

I started with a Hot Running BB and did get some “Pegging” of my Temperature Gauge.
I played with Thermostats 160/ 180 Deg., Fan Clutch, Radiators and I will say I finally got my Cooling issues under Control.

Using my eBay Laser Temp Gun, I felt the Readings on my Gauge was not correct, Always in or above the start of the Yellow Bar.

I also bought 3 Temperature Sending Units and all they do is Limit the Voltage going to Ground, I tried getting a consistent reading with each, bought a Mechanical Gauge just to see where my Temps were. Each Temperature Sending unit, all for the BB had different OHM resistant, from 570 to 640 OHM’s.

I had bought a small Hot Plate a while ago and decided to do a little test, Heated a pot of water till Boiling, Where I live in CT 210 Deg.+ . Had the Hot Plate on top of the Radiator Support, Put the Mechanical Gauge sending unit and one of the Sending units with a Jumper only to the Threads,
Mechanical 210, Console Gauge – pegged.
Kept the water at a Boil, switched the 3 Sending units around and one of them stayed just at the start of the Yellow !

Installed that on in my Intake Manifold (L-72 Winters Foundry) and with a 180 Deg. Thermostat, I can see the Temp climb over 180 and then settle down to Just above the Middle Mark, I will call that 180 Deg.

I also did a little Power Point/ Calculator Picture of what my Gauge will read.
It is Only what I think my car is at, while running.


13,314 Posts
Mine behaves and reads very similar to Timmy above for the same reasons... also checked in an electric jug with a thermometer hooked up to the gauge from cold

Originally.. factory.. they came out with 195 deg thermostats....but list replacements as 180 deg. I have no idea why.
The only original which Im only close to 100% knowing it is, has a slightly smaller diameter full open hole
My thermostat opens where the needle is on the pic above, and runs slightly below vertical around town and lightly over it on open highway

Slow getting to temp can be a couple things.
1/ no bypass hole ... This hole / valve allows min flow thru the thermostat so as not to get hot spots in the engine AND to allow the hotter water move up to the thermostat to open it AND to the sensor on the other side of the closed thermostat.
2/ The valve in the by pass hole has been removed or a by pass hole has been drilled and too big....allowing far too much coolant thru, cooling the engine too fast before reaches temp.
3/ Gauge reads wrong...dont use the infra red things... test as per mentioned above.. either method, pot or jug... u are reading actual temp at the sensor.. not the temp of the thermostat housing exterior surface.. which if shiny will be even more inaccurate.

Also the idiot light sensor goes on at 235 degs.. which is the same temp as the red line on the gauge.
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.