Bad Temp Gauge?

Today, my temp gauge on my 3A was pegged at 220. I shot the engine block with a temp gun and it was 160 give or take. So does this mean my temp gauge is bad? Can they go bad?

 

Yeah, I had one on an old Chevy truck that went bad after towing a loaded trailer.
It was either the gauge or sending unit, I installed a mechanical gauge so never figured out which was bad.

 

It is a mechanical gauge.

 

Oh

Sorry, I was thinking stock electric gauges.
I would think if a mechanical went bad (hole in the capillary tube and fluid loss) it would read low.

 

Now that it has cooled down, I'll look to see what it is reading.

 

The only mechanical gauge I had fail on me was one that was hooked to an f-head that severely overheated. I think it must’ve stretched the capillary. The needle still moved the same “distance of sweep” after that, but it was higher on the dial. It read 200° cold and about 290° at normal temp.

 

Mine is reading 175 cold. So I’m guessing it’s junk

 

They are simple devices, as I recall. A bulb with alcohol or some other liquid at the sender, and a tube from the bulb to a Bourdon tube that moves the dial. Same principle as a mechanical oil pressure gauge, with the addition of the alcohol. Changing vapor pressure with temperature moves the needle. Any device like this will fail after enough time and use.

 

Movement could wear out, tube could spring a leak. Anything made of copper or aluminum will accumulate stress over time and eventually crack.

Bourdon Tube - an overview | ScienceDirect Topics.

 

Mine stay cold a long time, then 140 on normal driving, and for more power, in hot weather, I go to 180 190. It is a direct gauge, same as on WWII Jeeps.
WOA8188 - GAUGE WATER TEMPERATURE STANDART - JEEPEST

 

The fact that it’s a less than a year old omix ada gauge might have something to do with it.