My sister called me tonight and said the temp guage on her 1996 was "up in the red for like 20 seconds" and has been jumping around. I told her what to do if it happens again and said I'd look at it tomorrow.

Anywhere specific to start? I was thinking thermostat.

Thanks.

 

thermostat, coolant level (ie-slow leak so it's not reading well/causing a massive air bubble), and maybe a small air bubble that's getting stuck in the water pump at low rpm.