Temperature sensor.
I have been trouble shooting the temperature gauge in the 1980 Corvette. Have to give Bikespace kudo's for posting the link to a wiring diagram as I haven't ordered the correct manuals yet. Wouldn't you know it, PO had a black and green wire hooked up(wrong) dark green wire was suppose to be used!Here is my dilemma, The engine I have is not original and after removing the valve cover I found the stamp markings to be 882 heads and stamped 76. This engine has been rebuilt as the vin number on the block has been machined down and stamped Z4. I am assuming this is a 1976 engine. When I looked up the temp sensor it shows an exact sensor for a 1980 and it has a plastic connector for connection. However the one on the engine has a single prong connector. I have determined that the wiring and gauge is working properly and now I need to replace the sensor. I have read some of the post about matching the right sensor to the car. If I replace the sensor with the 1976 type, will it suffice or should I purchase the one for the 80 model and change out the wiring connector. Your thoughts on the matter.

 

If your car has the 80 temp gauge then you need a sensor for that gauge.
Of course at this point do you know for sure it is the correct gauge?
The gauge/sensor is not be determined by whatever year the heads are.

 

I feel certain that the gauge is correct. As for the heads, just adding little more info on what I had for an engine. Thanx for the info.

 

I'm glad the wiring diagram was helpful!

I would think that you need the 80 sender to match your 80 gauges. It has a single blade connector, as you found. You may want to pick up an IR temperature gun to verify the readings you get. You can also check the internal resistance of the sender you already have with a multimeter. Willcox Corvette has instructions on dialing in your gauges, and checking the sender.

 

The 333882 heads for 76 had a 1/2"-14 NPT temperature sensor, I don't know what the 80 heads had for a thread size, but it may have been the later 3/8"-18 NPT.
You may need a reducer fitting if the 80 is a smaller thread.

Good luck with those 76 333882 heads," they are prone to cracking due to a GM redesign in 75 that allowed more exhaust flow through a new double heat-riser passage. When the heads were redesigned the uppermost cooling passage under the rocker arm studs was eliminated. The former cooling passage became part of the intake passage before the mixture reached the valve. This redesign, and later regular production 333882 heads have an irregularly shaped intake port that doesn’t permit the mixture to flow smoothly at high rpm. They also run hotter than any of the earlier heads. The additional cylinder head heat keeps combustion temperatures higher, thereby reducing exhaust emission levels. Furthermore, beginning in 1975 the carburetor adjustments were made leaner, which creates more heat. The exhaust flows less freely because of the catalytic converter (first used in 1975) in the exhaust system, and this causes even more heat. As a result, with cooling passages eliminated and high engine temperatures, cylinder head cracking is a real problem."

 

Today I attempted to pull the sensor out and dang it is not a sealed thermal coupling type fit. I proceeded to locate the petcock to drain the coolant in which I could not find one. Loosened the fan shroud and pulled it away and maybe it was hiding there. Nope, notta, zilch. Glad I picked up a syphoning pump and removed the coolant. Instead of ordering a switch and waiting for it to come in, off to O'reillys . The only single pole sensor they had was a cheap $19 after market. Well picked it up and installed. I replaced the coolant and then with everything crossed(including Butt cheeks) I started her up to see if I had corrected my problem and low and behold, the temperature started rising. It settled out around 200 degrees and I will verify with an infrared heat gun. It had a new 185 degree thermostat installed. Another issue solved. Now to shimming the starter.
KenSny, thanks for the tip on the 882's, but what puzzled me today when I changed out the left valve cover, it did not have the serial number with 882. Anyways when the old girl gets most of the mechanical issues done, I will be looking into a crate motor set up. But for now just going to enjoy the ride.

 

Good job.
I would be interested in seeing your numbers - gauge vs infrared. If close I would like to know the O'Reillys number. I bought a couple in the past that were off by 20-25 degrees at operating temps. You have to realize that the sensor is non-linear, so only the "normal" operating temp should be of value to us.

 

Here is a few temps taken using a General IRT207 infrared temp gun. On the aluminum intake right below the goose neck(thermostat) 168 degrees, rear of intake 156 degrees and the water pump was at 187 degrees, The temperature gauge on the dash was running at 200 degrees. This car is setting on blocks and was at idle. I am waiting for parts to arrive for bushings and transverse spring replacement then will see how the temperature reacts while driving. The Oreilly's number was a Standard Brand TS76