Re: Temperature gauge not working

Posted by HH56 On 2025/3/23 10:56:01

Pivot points may be sort of hidden under the faceplate so if Kev doesn't have a good photo of his Packard gauge showing exactly where to look you can do a Google search for Bourdon tube pressure gauge There are several sites which show illustrations of a typical gauge and where the pivot is located. Here is one of them.

Generally the pivot points are part of the mechanism which connects the moving end of the Bourdon tube to the needle. Linkage will consist of a single or maybe several small pieces of metal linked together in some fashion to move the needle. Pivots are the points which support the needle or actually move where the attachments are made. Some gauges with limited needle movement have it so the needle is pulled directly by linkage via a single metal piece. Other gauges that need to have the needle move a greater distance such as in a circle all around the gauge have a small gear attached to the needle. In those the small tube movement is multiplied so the needle can be operated at a greater range by the piece(s) attached to the tube turning the gear. If your needle seems free and goes back to the relaxed position freely lube may be OK. As Kev said, the working fluid could have just leaked out so there is not enough to move the Bourdon tube. The actual Bourdon tube looks sturdy but can be deformed or bent easily so don't push or pull on the moving end of it very hard.

You can bench test the gauge out of the car by inserting the sensor bulb in a container of heated water. Typically, if your gauge only has marks such as C or H a container of room temperature water will have the needle at the low C end. Heated to somewhere around the engine thermostat range which is typically about 160 will be mid scale and with it boiling, the needle will be somewhere near the top or even past the H. If your gauge is calibrated in actual numbers you could use something like a meat or candy thermometer in the water to see how close the temps match.