Low engine coolant

Hello,
92 Pontiac Bonneville with a 3.8L (no supercharge). A while ago you guys helped me out when the temp would go up while the car was idleing. Last few days I have been getting a low engine coolant alarm
on the dash board once the engine warms up (not right away). The overflow tank is up to the mark for hot and the radiator is full. I opened the brass screw on top of the thermostat housing to see if air would bleed out but no air.
The car does not run hot so i'm thinking the computer is getting bad information. Where would the sensor be that sends this information to the computer? I don't see any wires going to the overflow tank??? Isn't that the normal place?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
They're usually mounted on the radiator tank.
Brian

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Probably about 1/3 way down on the suction side. If there is sufficent air it will move to that side of the radiator, especially as you speed up the engine.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

You need to have the engine running to bleed air from the system. You also need to take the bleeder screw about half to three quarters of the way out. When you get a constant stream of coolant, then it is bleed. Charles
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.