Thread: Temp Sender?

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When I put my 23 together I put the sender in the back of the intake manifold......highest temp it recorded there was 120 degrees. I moved it to the front, right by the thermostat housing and it went up to 150. Now, with a 190 thermostat it reads about 170 all the time. Not sure why it was so much cooler in the back of the intake.

Don

Thanks guys, I don't know were the correct place was thus the question. I do know that Chevy has used both locations at different times. It just never occured to me that there would be such a difference. It only makes sense if you think about it, the head location has just got's to be hotter governed by whats around it.

After reading what Tech and SG said I went and bought two more temp gauge and installed one in the Manifold by the Thermostat Housing, and the other in the passenger side head. I took the car out for a little drive I was really surprised at the different readings. The gauges are all Autometer manual gauges, the readings at cruising, and I was driving around on the country roads around here. Car is a 1957 2 Door Wagon, with a just rebuilt 383 and a Muncie M21 4 speed.



Car was driven around for about 20 min before I took these readings. Reading from Drivers side head 220 Degree's ( wish we had that little degree symbol) temp from passenger side head 230 degree's, temp from Intake Manifold 195 degree's. The readings being different bothered me some so I went back to the shop and changed the guages around. Drivers side to the manifold, passenger side to the drivers side, and the intake sender to the passenger side. A warning let the damn thing cool waaaay down before you do this, I was a little hasty and I am paying the price for my haste NOW.

Another little cruise and took the readings again. Drivers side head 220 degree's, passenger side head 235 degree's and the intake 190-200 degrees.

One interesting observation, while I was driving there is a big hill going into Guntersville on Hiway 69 down grade is about 3/4 or maybe a little more of a mile. When I topped the crest the readings were just about what is above. I shifted into neutral and let the car coast all the way to the bottom of the hill, I was doing right at 60 MPH and didn't loose much of that speed all the way down. The guages for both heads cooled way down to 195-200 degrees, the guage reading the intake manifold temp did not move and stayed right at 190.

I am going to leave all three gauges hooked up and watch this for a spell. I now believe that the head probably gives a hotter temp and for that reason alone may just be the correct place if you want to really know what is going on. Thanks again Folks!!

RS

Originally Posted by Hombre259

Car was driven around for about 20 min before I took these readings. Reading from Drivers side head 220º (wish we had that little degree symbol) temp from passenger side head 230º, temp from Intake Manifold 195º. The readings being different bothered me some so I went back to the shop and changed the guages around. Drivers side to the manifold, passenger side to the drivers side, and the intake sender to the passenger side. A warning let the damn thing cool waaaay down before you do this, I was a little hasty and I am paying the price for my haste NOW.

Another little cruise and took the readings again. Drivers side head 220º, passenger side head 235º and the intake 190º-200º.

One interesting observation, while I was driving there is a big hill going into Guntersville on Hiway 69 down grade is about 3/4 or maybe a little more of a mile. When I topped the crest the readings were just about what is above. I shifted into neutral and let the car coast all the way to the bottom of the hill, I was doing right at 60 MPH and didn't loose much of that speed all the way down. The guages for both heads cooled way down to 195º-200º, the guage reading the intake manifold temp did not move and stayed right at 190º.

I am going to leave all three gauges hooked up and watch this for a spell. I now believe that the head probably gives a hotter temp and for that reason alone may just be the correct place if you want to really know what is going on. Thanks again Folks!!

RS

Your wish has been granted, now you have it.

Mike

OK Mike Now how do I do it?

RS

It should be always mounted in the manifold. Mounting it in the head will give you a 20-25 deg hotter reading as the coolant is just circulating there in the hottest part of the head around the exhaust valves.
The biggest thing one must remember is that the sending unit in the manifold is reading the coolant at its hottest point, BUT the coolant being read is also leaving the motor and going into the radiator to be cooled down. So if the fan, radiator, water pump are doing there jobs, the coolant should be coming back into the block on the suction side of the lower hose at least 15-20 deg cooler.

Sunsetdart is right, that is why the ECU equipped motors do not use the head sensor to run EFI, they all have one in the manifold they use to tell the ECU what the final (actual) temp of the water is before it leaves the motor. The one in the head is used for a temp gage, at the heat source, not for actual water temp.

Pat

Originally Posted by Hombre259

OK Mike Now how do I do it?

RS

When you need to use the º, simply hold down the ALT key and press the 0186 keys.

Here are a few more for ya,

ALT 0162 = ¢, example - 25¢
ALT 0178 = ², example - H²O
ALT 0188 = ¼, example - drag strip is ¼ mile long
ALT 0189 = ½
ALT 0190 = ¾

Have fun playing,
Mike

Mike, you're my hero, thanks very much...

Originally Posted by techinspector1

Mike, you're my hero, thanks very much...

Tech, if you want to have a little fun try these, start at ALT 0128 and go all the way to ALT 0255. Gotta warn ya though, some are a little weird.

RS, sorry for getting off topic, I apologize!!

Mike