Dash Display Errors

On my Dodge Neon (1998) Dash Display it has been flaky for geez 5 years or so. The speedometer works, and sometimes it doesn't work. It just will go to zero, while driving. The odometer also of course stops recording. Yeah the odometer says 135,000 Miles, but is probably closer to 200,000.

Anyway the other guages also are intermittent. but differently. They just change readings.

Like the gas guage can go from full to empty in seconds and them come back to 1/3 tank or 3/4 or any other value, Ya just gotta go like a motorcycle. How far have i gone since the last fill up.

Those two the speedometer and gas I can live with and ignore. But the temp guage scares me.

It will warm to running temp as always, then as you are driving. and it is soo intermittent I have never caught it going up, but it will suddenly have an alarm going off and it it in the high temp area beeping at us.

But

Withinn a few seconds it slowly drops down back into the normal range area. Now I am never sure if it is relly over heating or also a flaky guage?

Can the engine go from the red overheating area on the guage temp wise, to normal temp areas in ohhhh ten seconds or so?

I myself do not think it could cool down that fast, and that this must also be a guage error. whats everyone here think?