Coolant flush advice, please

[voileauciel]

One important item to take note of: be very, VERY careful when re-installing the water pump bleed bolt. The threads it screws into are very soft and can easily strip. I made this mistake when I replaced my water pump last year.

[timsatx]

Yes yes, this is serious thread resurection. I was searching for an answer on this issue once again as it was never resolved. I installed a new sensor and it is still not woking. I also checked my gauge and I know it is working. I did all the bleeding and I have actually topped of the radiator a couple of times. Not much, just a tiny bit each time. I was wondering if it could be a grounding issue from the thread sealant. Anybody ever find that an issue?

[Jim __]

Thread sealant can definitely effect the ground.  Get an OHM meter and measure the resistance from the metal portion of the sending unit to the ground lead on the battery.  Should be about 1 ohm or less.  Disconnect the wire from the sending unit and connect it to ground through a 10 to 15 ohm resistor.  You should see at least half scale on the gauge.  Or, momentarily short the connection on the sending unit to true ground.  You should see full scale. 

[Nosmo]

Several years ago I had a problem with my temp gauge and found the wire terminals on the back of the gauge very corroded and a bit loose giving intermittent high resistance.  I removed the screws and cleaned the terminals with 600 grit sand paper and reinstalled them and problem solved.  NOTE if you try this, only take out ONE screw at a time, if you remove them all at once, the gauge will get loose and you might have to disassemble the instrument panel to reattach everything.  Ask me how I know........