1992 Maxima SE Temp gauge

Ok, here is another issue. The temp gauge has a mind of its own. Some days its fine and reads right in the middle. While I'm driving it will either shoot up to hot and stay there for about 5 minutes, then come back to normal, or drop to cold and stay there for the same amount of time then come back to normal.

It does not happen all the time but perhaps about once a month.
I'm waiting for the Mass Flow Air sensor to arrive any moment so I think it may have something to do with that...or not.

Any suggestions? Thermostat needs to be replaced? Bad sensor somewhere?

...Any suggestions? Thermostat needs to be replaced? Bad sensor somewhere?

Most propably oxidized connector at temp sensor. Clean, add contact grease. Sensor is '5$' and easily replaced.

Nothing to do with MAF; btw it needs to be changed only if problems exist, test shows malfunction.