Temp sensor swap

[Roger G.]

Do you use a thread sealer on the temp sensor?
Any tips on replacing it without losing a bunch of coolant?
And finally, torque setting?

THANKS

[Michael G.]

Re: Temp sensor swap

Do you use a thread sealer on the temp sensor?
Any tips on replacing it without losing a bunch of coolant?
And finally, torque setting?

THANKS

Roger,

You may need to remove a small amount of coolant from the radiator at the petcock. Personally never torque to a particular spec. Using a small amount of sealant I torque till sender is reasonably taunt.

[Stephen L.]

Re: Temp sensor swap

Sealant could act as an insulator causing a malfunction as the sensor electrical ground is thru the brass threads.

[Cliff P.]

Re: Temp sensor swap

No sealant. If you have new sensor ready and change first thing in morning or before car has been started that day lay rag around sending unit you will not loose enough coolant to get past the rag.

[Jim L.]

Re: Temp sensor swap

Do you use a thread sealer on the temp sensor?

I use anti-seize so I can remove the sender in the future, if need be. Teflon paste also works well. Don't worry about loss of a ground connection. The wedging action of tapered pipe threads always ensures metal-to-metal contact.

Any tips on replacing it without losing a bunch of coolant?

Drain a small amount of coolant out of the radiator before you start.

And finally, torque setting?

No specific torque setting. 1-1/2 to 2 turns after finger tight will seal well.

[Roger G.]

Re: Temp sensor swap

Well, this turned into an afternoon of frustration. The swap went well, however the sender 1513321 doesn't seem to be calibrated to the gage very well. It is reading way too low. The IR gun gives me 180 at the thermostat housing and the gage reads 120. I thought maybe the gage wasn't working correctly, but it pegs out when the cable is grounded. So I guess its back to the old sender

[Michael G.]

Re: Temp sensor swap

Well, this turned into an afternoon of frustration. The swap went well, however the sender 1513321 doesn't seem to be calibrated to the gage very well. It is reading way too low. The IR gun gives me 180 at the thermostat housing and the gage reads 120. I thought maybe the gage wasn't working correctly, but it pegs out when the cable is grounded. So I guess its back to the old sender

That seems to be the MO of the available temp senders. I probably purchased 3 before I found one that read close to what the gauge stated.

[Joe L.]

Re: Temp sensor swap

Well, this turned into an afternoon of frustration. The swap went well, however the sender 1513321 doesn't seem to be calibrated to the gage very well. It is reading way too low. The IR gun gives me 180 at the thermostat housing and the gage reads 120. I thought maybe the gage wasn't working correctly, but it pegs out when the cable is grounded. So I guess its back to the old sender

roger------



If you have an NOS GM #1513321 sender, I have found that those work quite well and indicate the correct temperature. Please report what happens when you install the original sender.

[Roger G.]

Re: Temp sensor swap

roger------



If you have an NOS GM #1513321 sender, I have found that those work quite well and indicate the correct temperature. Please report what happens when you install the original sender.

Joe, will do...it is a NOS unit... So I was surprised.... Before I do the swap back, I'm going to take it out and clean the Teflon off the threads and give it another shot... Or maybe try to ground it with a wire to the barrel

[Joe L.]

Re: Temp sensor swap

Joe, will do...it is a NOS unit... So I was surprised.... Before I do the swap back, I'm going to take it out and clean the Teflon off the threads and give it another shot... Or maybe try to ground it with a wire to the barrel

roger-------


That's a good thing to try. Personally, I absolutely do not recommend using ANYTHING on these threads. Once-upon-a-time I replaced a sender and used teflon tape on the threads. The gauge turned up being quite erratic and I just could not understand why. Finally, I surmised that maybe the teflon tape had somehow interfered. So, I completely removed the tape from the threads of the sender and the head. I re-installed the sender and it worked perfectly.

The pipe threads on the sender are known as "Dryseal" and require no sealer of any kind. GM originally used none.

Torque the sender to 20 lb/ft which is the GM specification.

[Roger G.]

Re: Temp sensor swap

roger-------


That's a good thing to try. Personally, I absolutely do not recommend using ANYTHING on these threads. Once-upon-a-time I replaced a sender and used teflon tape on the threads. The gauge turned up being quite erratic and I just could not understand why. Finally, I surmised that maybe the teflon tape had somehow interfered. So, I completely removed the tape from the threads of the sender and the head. I re-installed the sender and it worked perfectly.

The pipe threads on the sender are known as "Dryseal" and require no sealer of any kind. GM originally used none.

Torque the sender to 20 lb/ft which is the GM specification.

After work today, I got an alligator clamp on the barrel and grounded it. It still reads at 120 with the engine at 180. I then connected a new BWD WT 203 from O'Reillys to the sensor cable and grounded it with the alligator clamp. Stuck it down by the manifold and let it warm up. Then shot it at different temps with an IR gun to see how accurate it was to the gage. It got fairly accurate readings on the gage.

So looks like a bad NOS GM #1513321. Next step is to take it out and map the resistance at different temps before returning it. Is this data available?

[John H.]

Re: Temp sensor swap

So looks like a bad NOS GM #1513321. Next step is to take it out and map the resistance at different temps before returning it. Is this data available?

Roger -

The chart below is a composite of several #1513321 sender tests.


TempSenderCurveDZ.jpg

[Roger G.]

Re: Temp sensor swap

Roger -

The chart below is a composite of several #1513321 sender tests.


[ATTACH=CONFIG]52017[/ATTACH]

Thanks John....That's exactly what I was looking for! And it is more linear than I though it would be Is this published?

[Joe L.]

Re: Temp sensor swap

After work today, I got an alligator clamp on the barrel and grounded it. It still reads at 120 with the engine at 180. I then connected a new BWD WT 203 from O'Reillys to the sensor cable and grounded it with the alligator clamp. Stuck it down by the manifold and let it warm up. Then shot it at different temps with an IR gun to see how accurate it was to the gage. It got fairly accurate readings on the gage.

So looks like a bad NOS GM #1513321. Next step is to take it out and map the resistance at different temps before returning it. Is this data available?

Roger-------


Did you try the 1513321 with the teflon tape removed and cleaned up? Did you install the BWD sender with teflon tape?

[John H.]

Re: Temp sensor swap

Thanks John....That's exactly what I was looking for! And it is more linear than I though it would be Is this published?

Roger -

It was put together by Dave Zuberer, published over on the C1/C2 Forum at CF about 4 years ago.