[Mgs] A short tale of parts & service [Postscript]

Barney Gaylord barneymg at mgaguru.com
Sun Oct 7 18:10:16 MDT 2018

Remove the gauge from the dash.  Unscrew the font 
chome ring to remove the face glass.  Place the 
sensor bulb in boiling water.  Pull off the 
needle, reposition it to point at 212dF, and 
press it back on.  You can then use a thermometer 
with variable water temperatures to check if the 
gauge reads correctly at diffeent temperatures.

When it works properly it can read higher 
temperatures up into the oil pressure range.  The 
temperature needle should run out of mechanical 
travel around 82-psi (if you can warm it up to 
about 250dF).  If it stops before it gets that 
far, then the bourdon tube may have been stetched 
beyond its electic limit by overheating, in which all bets are off on accuracy.

Barney Gaylord
1958 MGA with an attitude

At 05:04 PM 10/7/2018, Max Heim via Mgs wrote:
>I just got the engine back together, but now the 
>temperature gauge is malfunctioning.
>It seems to have got stuck at about 220. 
>That’s what it was reading before I even tried 
>to start the car. After warming up to operating 
>temp (estimated, of course), the gauge had 
>climbed into the oil pressure zone, reading at 
>85 psi. At this point my cheap temp gun had the 
>thermostat housing at around 180.
>Anyone seen this before? Any suggestions?
>Max Heim
>'66 MGB

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