my temp gauge keeps going up and down on my 98 stratus, i thought maybe it could be my thermostat or maybe i need to change the head gasket, any suggestions

 

last time the cooling sys was flushed? most newer cars have t-stats that close when cold instead of opening when hot (they fail open). if the cooling sys is gummed up the t-stst may have trouble opening and closing. be a good idea to change the t-stat and have the cooling sys flushed, call around for prices, might save some money. happy motoring.