Temperature sending unit location
Thread Starter
Racer
Joined: Feb 2012
Posts: 333
Likes: 2
From: Aurora Colorado
Temperature sending unit location
How much coolant will gush out if I remove my temp sending unit on my 71 small block? Previous owner put headers on that had the cut out for the unit on the right rear of the engine then ran an ugly wire from the alternator wiring harness around the back of the engine to the new location. My side pipe headers have the cut out in the correct location and I would like to relocate it back to the correct location. Should I just drain all the brand new coolant?
Also, as my engine warms up from cold my temp gauge rises to max then drops almost back all the way two times as the thermostat opens and closes then levels out to normal once the engine is up to operating temp. Is that because of the sensor being in the wrong location? Thanks for any help.
Also, as my engine warms up from cold my temp gauge rises to max then drops almost back all the way two times as the thermostat opens and closes then levels out to normal once the engine is up to operating temp. Is that because of the sensor being in the wrong location? Thanks for any help.
Le Mans Master
Joined: May 2006
Posts: 5,814
Likes: 414
From: Pittsburgh suburbs Pa.
How much coolant will gush out if I remove my temp sending unit on my 71 small block? Previous owner put headers on that had the cut out for the unit on the right rear of the engine then ran an ugly wire from the alternator wiring harness around the back of the engine to the new location. My side pipe headers have the cut out in the correct location and I would like to relocate it back to the correct location. Should I just drain all the brand new coolant?
Also, as my engine warms up from cold my temp gauge rises to max then drops almost back all the way two times as the thermostat opens and closes then levels out to normal once the engine is up to operating temp. Is that because of the sensor being in the wrong location? Thanks for any help.
Also, as my engine warms up from cold my temp gauge rises to max then drops almost back all the way two times as the thermostat opens and closes then levels out to normal once the engine is up to operating temp. Is that because of the sensor being in the wrong location? Thanks for any help.
Thread Starter
Racer
Joined: Feb 2012
Posts: 333
Likes: 2
From: Aurora Colorado
Ok, I tried to relocate the temp sender to the correct side of the engine, unfortunately I can not for the life of me get the plug out with the engine in the car, just can't get enough leverage so that will just have to wait. I replaced the thermostat that I thought was a 180 ° was actually 195 °. I put in a Robert Shaw Stewart style tstat that has 3 holes drilled in it. Now the engine won't really heat up past, I'm guessing 120-130 °, just over the 100 ° mark. Yesterday I drove it about 30 miles each way for a wheel alignment in about 60 ° sunny weather. I'm not even sure the tstat is even opening, the upper hose feels warm but not much pressure when I squeeze it after driving it. Could those holes be letting just enough flow through the radiator to keep the engine cool?
Melting Slicks
Joined: Feb 2006
Posts: 3,105
Likes: 96
From: Sunrise FL
Also, as my engine warms up from cold my temp gauge rises to max then drops almost back all the way two times as the thermostat opens and closes then levels out to normal once the engine is up to operating temp. Is that because of the sensor being in the wrong location? Thanks for any help.
Not sure if 3 holes are too many...
Last edited by mikem350; Mar 13, 2015 at 05:37 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
You might lose 1/2 gallon of coolant (max) if you just pull the temp sender out. But, you can drain that amount (or a little more) from the radiator into a clean bucket BEFORE removing the sender, then pour it back in when you get done with the swap.
