This is just weird !!  Does anybody know what would cause this? Engine running. Fans on. IR gun says 192 at the tank. I was putting the screw back in the gauge panel and when I moved the screwdriver past the front of the gauge I noticed it moved so I took this video.

Thanks in advance for any ideas.


Doug M



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Original Post

Your screwdriver has a magnetic tip. 

You are messing with the lines of magnetic flux in the gauge mechanism. It’s a coil that the needle pivots on. 


Thanks Rocky,   That has to be the reason. I'm pretty sure the screwdriver is not magnetic but I'll check it. Had the car out last night and was running hotter than usual. It's almost always an electrical problem so I pulled the gauge panel and checked all the connections.  I'll get it back out in the next day or so and see if I made any difference.  With no screwdriver anywhere near it.


Thanks again

Magnetic tip screwdriver!  Verify the accuracy of your gauge with an IR Temp Gun at the temp sensor on the block.  That's the only way to know what's really going on with your engine temp.  I found my factory gauge to be quite accurate!

The screwdriver WAS ever so slightly magnetized.  I had to move down to the tiniest finishing screw before it would lift it off the counter. But it did. I had no idea the gauge was that sensitive. And yes, I have checked with an IR gun several times over the years and my gauge is dead accurate. 

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